Reland "Support 'xcode parallelization' flag on the test blocks level."

This reverts commit c79a7556da9e8e45df3dc0a160d8dd304a2b25cf.

Reason for revert: discussed offline; should be fine on branches due to how run.py parses args_json.

Original change's description:
> Revert "Support 'xcode parallelization' flag on the test blocks level."
> 
> This reverts commit 0f143592b6e3c6db8e13280055065f7ea6b38f1f.
> 
> Reason for revert: xcode parallelization flag should only be present for M73+.
> 
> Original change's description:
> > Support 'xcode parallelization' flag on the test blocks level.
> > 
> > Bug:920300
> > Change-Id: I6a926e12788bff54811b3c034106516e31224a88
> > Recipe-Nontrivial-Roll: build_limited_scripts_slave
> > Reviewed-on: https://chromium-review.googlesource.com/c/1404137
> > Commit-Queue: Maksym Onufriienko <monufriienko@chromium.org>
> > Reviewed-by: Sergey Berezin <sergeyberezin@chromium.org>
> 
> TBR=justincohen@chromium.org,sergeyberezin@chromium.org,lindsayw@chromium.org,monufriienko@chromium.org
> 
> Change-Id: Id6d0cce488714bda96df7b2aba662c97993f5780
> No-Presubmit: true
> No-Tree-Checks: true
> No-Try: true
> Bug: 920300
> Reviewed-on: https://chromium-review.googlesource.com/c/1407213
> Reviewed-by: John Budorick <jbudorick@chromium.org>
> Commit-Queue: John Budorick <jbudorick@chromium.org>

TBR=justincohen@chromium.org,sergeyberezin@chromium.org,lindsayw@chromium.org,jbudorick@chromium.org,monufriienko@chromium.org

Change-Id: I3f27ea8a3567613442f08d1fb296e22b6e13e6e2
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: 920300
Reviewed-on: https://chromium-review.googlesource.com/c/1407218
Reviewed-by: John Budorick <jbudorick@chromium.org>
Commit-Queue: John Budorick <jbudorick@chromium.org>
diff --git a/scripts/slave/README.recipes.md b/scripts/slave/README.recipes.md
index 1c5e087..9476739 100644
--- a/scripts/slave/README.recipes.md
+++ b/scripts/slave/README.recipes.md
@@ -2456,7 +2456,7 @@
 
 Checks out Chromium.
 
-&mdash; **def [collect](/scripts/slave/recipe_modules/ios/api.py#987)(self, tasks, upload_test_results=True):**
+&mdash; **def [collect](/scripts/slave/recipe_modules/ios/api.py#988)(self, tasks, upload_test_results=True):**
 
 Collects the given Swarming task results.
 
@@ -2466,15 +2466,15 @@
 
 &mdash; **def [get\_mac\_toolchain\_cmd](/scripts/slave/recipe_modules/ios/api.py#331)(self):**
 
-&mdash; **def [get\_perftest\_data](/scripts/slave/recipe_modules/ios/api.py#1175)(self, path):**
+&mdash; **def [get\_perftest\_data](/scripts/slave/recipe_modules/ios/api.py#1176)(self, path):**
 
 &emsp; **@staticmethod**<br>&mdash; **def [get\_step\_name](/scripts/slave/recipe_modules/ios/api.py#597)(test):**
 
-&mdash; **def [isolate](/scripts/slave/recipe_modules/ios/api.py#766)(self, scripts_dir='src/ios/build/bots/scripts'):**
+&mdash; **def [isolate](/scripts/slave/recipe_modules/ios/api.py#768)(self, scripts_dir='src/ios/build/bots/scripts'):**
 
 Isolates the tests specified in this bot's build config.
 
-&mdash; **def [isolate\_earlgrey\_test](/scripts/slave/recipe_modules/ios/api.py#711)(self, test, shard_size, tmp_dir, isolate_template):**
+&mdash; **def [isolate\_earlgrey\_test](/scripts/slave/recipe_modules/ios/api.py#713)(self, test, shard_size, tmp_dir, isolate_template):**
 
 Isolate earlgrey test into small shards
 
@@ -2482,16 +2482,16 @@
 
 Isolates a single test.
 
-&emsp; **@property**<br>&mdash; **def [most\_recent\_app\_dir](/scripts/slave/recipe_modules/ios/api.py#1260)(self):**
+&emsp; **@property**<br>&mdash; **def [most\_recent\_app\_dir](/scripts/slave/recipe_modules/ios/api.py#1261)(self):**
 
 Returns the path (relative to checkout working dir) of the most recently
 compiled apps.
 
-&emsp; **@property**<br>&mdash; **def [most\_recent\_app\_path](/scripts/slave/recipe_modules/ios/api.py#1247)(self):**
+&emsp; **@property**<br>&mdash; **def [most\_recent\_app\_path](/scripts/slave/recipe_modules/ios/api.py#1248)(self):**
 
 Returns the Path to the directory of the most recently compiled apps.
 
-&emsp; **@property**<br>&mdash; **def [most\_recent\_iossim](/scripts/slave/recipe_modules/ios/api.py#1275)(self):**
+&emsp; **@property**<br>&mdash; **def [most\_recent\_iossim](/scripts/slave/recipe_modules/ios/api.py#1276)(self):**
 
 Returns the path to the most recently compiled iossim.
 
@@ -2525,11 +2525,11 @@
     out directory, so must have already been compiled.
   url: URL of the symbol server to upload to.
 
-&mdash; **def [test\_swarming](/scripts/slave/recipe_modules/ios/api.py#1224)(self, scripts_dir='src/ios/build/bots/scripts', upload_test_results=True):**
+&mdash; **def [test\_swarming](/scripts/slave/recipe_modules/ios/api.py#1225)(self, scripts_dir='src/ios/build/bots/scripts', upload_test_results=True):**
 
 Runs tests on Swarming as instructed by this bot's build config.
 
-&mdash; **def [trigger](/scripts/slave/recipe_modules/ios/api.py#854)(self, tasks):**
+&mdash; **def [trigger](/scripts/slave/recipe_modules/ios/api.py#855)(self, tasks):**
 
 Triggers the given Swarming tasks.
 
diff --git a/scripts/slave/recipe_modules/ios/api.py b/scripts/slave/recipe_modules/ios/api.py
index 9cbaddd..59b2e89 100644
--- a/scripts/slave/recipe_modules/ios/api.py
+++ b/scripts/slave/recipe_modules/ios/api.py
@@ -656,6 +656,8 @@
       '--config-variable', 'shards', self.m.json.dumps(test.get('shards') or 1),
       '--config-variable', 'test_args', self.m.json.dumps(
           test.get('test args') or []),
+      '--config-variable', 'xcode_parallelization', (
+          'true' if test.get('xcode parallelization') else 'false'),
       '--config-variable', 'test_cases', self.m.json.dumps(test_cases or []),
       '--config-variable', 'xctest', (
         'true' if test.get('xctest') else 'false'),
@@ -776,7 +778,8 @@
       '{"test_args": <(test_args), \
         "xctest": <(xctest), \
         "test_cases": <(test_cases), \
-        "restart": <(restart)}',
+        "restart": <(restart), \
+        "xcode-parallelization": <(xcode_parallelization)}',
       '--out-dir', '${ISOLATED_OUTDIR}',
       '--retries', self.__config.get('retries', '3'),
       '--shards', '<(shards)',
@@ -786,8 +789,6 @@
       '--wpr-tools-path', '<(wpr_tools_path)',
       '--replay-path', '<(replay_path)'
     ]
-    if self.__config.get('xcode parallelization', False):
-      cmd.append('--xcode-parallelization')
 
     files = [
       # .apps are directories. Need the trailing slash to isolate the
diff --git a/scripts/slave/recipe_modules/ios/examples/full.expected/basic.json b/scripts/slave/recipe_modules/ios/examples/full.expected/basic.json
index d52974f..e503319 100644
--- a/scripts/slave/recipe_modules/ios/examples/full.expected/basic.json
+++ b/scripts/slave/recipe_modules/ios/examples/full.expected/basic.json
@@ -774,7 +774,7 @@
       "--json-output",
       "/path/to/tmp/json",
       "copy",
-      "{'conditions': [['OS == \"ios\"', {'variables': {'files': ['<(app_path)/', 'src/ios/build/bots/scripts/', 'src/out/Debug-iphonesimulator/iossim'], 'command': ['src/ios/build/bots/scripts/run.py', '--app', '<(app_path)', '--args-json', '{\"test_args\": <(test_args),         \"xctest\": <(xctest),         \"test_cases\": <(test_cases),         \"restart\": <(restart)}', '--out-dir', '${ISOLATED_OUTDIR}', '--retries', '3', '--shards', '<(shards)', '--<(xcode_arg_name)', '<(xcode_version)', '--mac-toolchain-cmd', './mac_toolchain', '--xcode-path', 'Xcode.app', '--wpr-tools-path', '<(wpr_tools_path)', '--replay-path', '<(replay_path)', '--iossim', 'src/out/Debug-iphonesimulator/iossim', '--platform', '<(platform)', '--version', '<(version)']}}]]}",
+      "{'conditions': [['OS == \"ios\"', {'variables': {'files': ['<(app_path)/', 'src/ios/build/bots/scripts/', 'src/out/Debug-iphonesimulator/iossim'], 'command': ['src/ios/build/bots/scripts/run.py', '--app', '<(app_path)', '--args-json', '{\"test_args\": <(test_args),         \"xctest\": <(xctest),         \"test_cases\": <(test_cases),         \"restart\": <(restart),         \"xcode-parallelization\": <(xcode_parallelization)}', '--out-dir', '${ISOLATED_OUTDIR}', '--retries', '3', '--shards', '<(shards)', '--<(xcode_arg_name)', '<(xcode_version)', '--mac-toolchain-cmd', './mac_toolchain', '--xcode-path', 'Xcode.app', '--wpr-tools-path', '<(wpr_tools_path)', '--replay-path', '<(replay_path)', '--iossim', 'src/out/Debug-iphonesimulator/iossim', '--platform', '<(platform)', '--version', '<(version)']}}]]}",
       "[START_DIR]/template.isolate"
     ],
     "cwd": "[START_DIR]/src",
@@ -793,7 +793,7 @@
       "@@@STEP_LOG_LINE@template.isolate@            \"--app\", @@@",
       "@@@STEP_LOG_LINE@template.isolate@            \"<(app_path)\", @@@",
       "@@@STEP_LOG_LINE@template.isolate@            \"--args-json\", @@@",
-      "@@@STEP_LOG_LINE@template.isolate@            \"{\\\"test_args\\\": <(test_args),         \\\"xctest\\\": <(xctest),         \\\"test_cases\\\": <(test_cases),         \\\"restart\\\": <(restart)}\", @@@",
+      "@@@STEP_LOG_LINE@template.isolate@            \"{\\\"test_args\\\": <(test_args),         \\\"xctest\\\": <(xctest),         \\\"test_cases\\\": <(test_cases),         \\\"restart\\\": <(restart),         \\\"xcode-parallelization\\\": <(xcode_parallelization)}\", @@@",
       "@@@STEP_LOG_LINE@template.isolate@            \"--out-dir\", @@@",
       "@@@STEP_LOG_LINE@template.isolate@            \"${ISOLATED_OUTDIR}\", @@@",
       "@@@STEP_LOG_LINE@template.isolate@            \"--retries\", @@@",
@@ -851,7 +851,7 @@
       "--json-output",
       "/path/to/tmp/json",
       "copy",
-      "{\n  \"args\": [\n    \"--config-variable\", \n    \"OS\", \n    \"ios\", \n    \"--config-variable\", \n    \"app_path\", \n    \"src/out/Debug-iphonesimulator/fake test 0.app\", \n    \"--config-variable\", \n    \"restart\", \n    \"false\", \n    \"--config-variable\", \n    \"shards\", \n    \"1\", \n    \"--config-variable\", \n    \"test_args\", \n    \"[]\", \n    \"--config-variable\", \n    \"test_cases\", \n    \"[\\\"CacheTestCase\\\", \\\"KeyboardTestCase\\\"]\", \n    \"--config-variable\", \n    \"xctest\", \n    \"false\", \n    \"--config-variable\", \n    \"use_trusted_cert\", \n    \"false\", \n    \"--isolate\", \n    \"[START_DIR]/template.isolate\", \n    \"--isolated\", \n    \"[CLEANUP]/isolate_tmp_1/0_0.isolated\", \n    \"--path-variable\", \n    \"app_path\", \n    \"src/out/Debug-iphonesimulator/fake test 0.app\", \n    \"--config-variable\", \n    \"wpr_tools_path\", \n    \"NO_PATH\", \n    \"--config-variable\", \n    \"replay_path\", \n    \"NO_PATH\", \n    \"--config-variable\", \n    \"xcode_arg_name\", \n    \"xcode-build-version\", \n    \"--config-variable\", \n    \"xcode_version\", \n    \"9abc\", \n    \"--config-variable\", \n    \"platform\", \n    \"fake device 0\", \n    \"--config-variable\", \n    \"version\", \n    \"11.0\"\n  ], \n  \"dir\": \"[START_DIR]\", \n  \"version\": 1\n}",
+      "{\n  \"args\": [\n    \"--config-variable\", \n    \"OS\", \n    \"ios\", \n    \"--config-variable\", \n    \"app_path\", \n    \"src/out/Debug-iphonesimulator/fake test 0.app\", \n    \"--config-variable\", \n    \"restart\", \n    \"false\", \n    \"--config-variable\", \n    \"shards\", \n    \"1\", \n    \"--config-variable\", \n    \"test_args\", \n    \"[]\", \n    \"--config-variable\", \n    \"xcode_parallelization\", \n    \"false\", \n    \"--config-variable\", \n    \"test_cases\", \n    \"[\\\"CacheTestCase\\\", \\\"KeyboardTestCase\\\"]\", \n    \"--config-variable\", \n    \"xctest\", \n    \"false\", \n    \"--config-variable\", \n    \"use_trusted_cert\", \n    \"false\", \n    \"--isolate\", \n    \"[START_DIR]/template.isolate\", \n    \"--isolated\", \n    \"[CLEANUP]/isolate_tmp_1/0_0.isolated\", \n    \"--path-variable\", \n    \"app_path\", \n    \"src/out/Debug-iphonesimulator/fake test 0.app\", \n    \"--config-variable\", \n    \"wpr_tools_path\", \n    \"NO_PATH\", \n    \"--config-variable\", \n    \"replay_path\", \n    \"NO_PATH\", \n    \"--config-variable\", \n    \"xcode_arg_name\", \n    \"xcode-build-version\", \n    \"--config-variable\", \n    \"xcode_version\", \n    \"9abc\", \n    \"--config-variable\", \n    \"platform\", \n    \"fake device 0\", \n    \"--config-variable\", \n    \"version\", \n    \"11.0\"\n  ], \n  \"dir\": \"[START_DIR]\", \n  \"version\": 1\n}",
       "[CLEANUP]/isolate_tmp_1/0_0.isolated.gen.json"
     ],
     "cwd": "[START_DIR]/src",
@@ -878,6 +878,9 @@
       "@@@STEP_LOG_LINE@0_0.isolated.gen.json@    \"test_args\", @@@",
       "@@@STEP_LOG_LINE@0_0.isolated.gen.json@    \"[]\", @@@",
       "@@@STEP_LOG_LINE@0_0.isolated.gen.json@    \"--config-variable\", @@@",
+      "@@@STEP_LOG_LINE@0_0.isolated.gen.json@    \"xcode_parallelization\", @@@",
+      "@@@STEP_LOG_LINE@0_0.isolated.gen.json@    \"false\", @@@",
+      "@@@STEP_LOG_LINE@0_0.isolated.gen.json@    \"--config-variable\", @@@",
       "@@@STEP_LOG_LINE@0_0.isolated.gen.json@    \"test_cases\", @@@",
       "@@@STEP_LOG_LINE@0_0.isolated.gen.json@    \"[\\\"CacheTestCase\\\", \\\"KeyboardTestCase\\\"]\", @@@",
       "@@@STEP_LOG_LINE@0_0.isolated.gen.json@    \"--config-variable\", @@@",
@@ -926,7 +929,7 @@
       "--json-output",
       "/path/to/tmp/json",
       "copy",
-      "{\n  \"args\": [\n    \"--config-variable\", \n    \"OS\", \n    \"ios\", \n    \"--config-variable\", \n    \"app_path\", \n    \"src/out/Debug-iphonesimulator/fake test 0.app\", \n    \"--config-variable\", \n    \"restart\", \n    \"false\", \n    \"--config-variable\", \n    \"shards\", \n    \"1\", \n    \"--config-variable\", \n    \"test_args\", \n    \"[]\", \n    \"--config-variable\", \n    \"test_cases\", \n    \"[\\\"PasswordsTestCase\\\", \\\"TabUITestCase\\\"]\", \n    \"--config-variable\", \n    \"xctest\", \n    \"false\", \n    \"--config-variable\", \n    \"use_trusted_cert\", \n    \"false\", \n    \"--isolate\", \n    \"[START_DIR]/template.isolate\", \n    \"--isolated\", \n    \"[CLEANUP]/isolate_tmp_1/0_1.isolated\", \n    \"--path-variable\", \n    \"app_path\", \n    \"src/out/Debug-iphonesimulator/fake test 0.app\", \n    \"--config-variable\", \n    \"wpr_tools_path\", \n    \"NO_PATH\", \n    \"--config-variable\", \n    \"replay_path\", \n    \"NO_PATH\", \n    \"--config-variable\", \n    \"xcode_arg_name\", \n    \"xcode-build-version\", \n    \"--config-variable\", \n    \"xcode_version\", \n    \"9abc\", \n    \"--config-variable\", \n    \"platform\", \n    \"fake device 0\", \n    \"--config-variable\", \n    \"version\", \n    \"11.0\"\n  ], \n  \"dir\": \"[START_DIR]\", \n  \"version\": 1\n}",
+      "{\n  \"args\": [\n    \"--config-variable\", \n    \"OS\", \n    \"ios\", \n    \"--config-variable\", \n    \"app_path\", \n    \"src/out/Debug-iphonesimulator/fake test 0.app\", \n    \"--config-variable\", \n    \"restart\", \n    \"false\", \n    \"--config-variable\", \n    \"shards\", \n    \"1\", \n    \"--config-variable\", \n    \"test_args\", \n    \"[]\", \n    \"--config-variable\", \n    \"xcode_parallelization\", \n    \"false\", \n    \"--config-variable\", \n    \"test_cases\", \n    \"[\\\"PasswordsTestCase\\\", \\\"TabUITestCase\\\"]\", \n    \"--config-variable\", \n    \"xctest\", \n    \"false\", \n    \"--config-variable\", \n    \"use_trusted_cert\", \n    \"false\", \n    \"--isolate\", \n    \"[START_DIR]/template.isolate\", \n    \"--isolated\", \n    \"[CLEANUP]/isolate_tmp_1/0_1.isolated\", \n    \"--path-variable\", \n    \"app_path\", \n    \"src/out/Debug-iphonesimulator/fake test 0.app\", \n    \"--config-variable\", \n    \"wpr_tools_path\", \n    \"NO_PATH\", \n    \"--config-variable\", \n    \"replay_path\", \n    \"NO_PATH\", \n    \"--config-variable\", \n    \"xcode_arg_name\", \n    \"xcode-build-version\", \n    \"--config-variable\", \n    \"xcode_version\", \n    \"9abc\", \n    \"--config-variable\", \n    \"platform\", \n    \"fake device 0\", \n    \"--config-variable\", \n    \"version\", \n    \"11.0\"\n  ], \n  \"dir\": \"[START_DIR]\", \n  \"version\": 1\n}",
       "[CLEANUP]/isolate_tmp_1/0_1.isolated.gen.json"
     ],
     "cwd": "[START_DIR]/src",
@@ -953,6 +956,9 @@
       "@@@STEP_LOG_LINE@0_1.isolated.gen.json@    \"test_args\", @@@",
       "@@@STEP_LOG_LINE@0_1.isolated.gen.json@    \"[]\", @@@",
       "@@@STEP_LOG_LINE@0_1.isolated.gen.json@    \"--config-variable\", @@@",
+      "@@@STEP_LOG_LINE@0_1.isolated.gen.json@    \"xcode_parallelization\", @@@",
+      "@@@STEP_LOG_LINE@0_1.isolated.gen.json@    \"false\", @@@",
+      "@@@STEP_LOG_LINE@0_1.isolated.gen.json@    \"--config-variable\", @@@",
       "@@@STEP_LOG_LINE@0_1.isolated.gen.json@    \"test_cases\", @@@",
       "@@@STEP_LOG_LINE@0_1.isolated.gen.json@    \"[\\\"PasswordsTestCase\\\", \\\"TabUITestCase\\\"]\", @@@",
       "@@@STEP_LOG_LINE@0_1.isolated.gen.json@    \"--config-variable\", @@@",
@@ -1001,7 +1007,7 @@
       "--json-output",
       "/path/to/tmp/json",
       "copy",
-      "{\n  \"args\": [\n    \"--config-variable\", \n    \"OS\", \n    \"ios\", \n    \"--config-variable\", \n    \"app_path\", \n    \"src/out/Debug-iphonesimulator/fake test 0.app\", \n    \"--config-variable\", \n    \"restart\", \n    \"false\", \n    \"--config-variable\", \n    \"shards\", \n    \"1\", \n    \"--config-variable\", \n    \"test_args\", \n    \"[]\", \n    \"--config-variable\", \n    \"test_cases\", \n    \"[\\\"ToolBarTestCase\\\"]\", \n    \"--config-variable\", \n    \"xctest\", \n    \"false\", \n    \"--config-variable\", \n    \"use_trusted_cert\", \n    \"false\", \n    \"--isolate\", \n    \"[START_DIR]/template.isolate\", \n    \"--isolated\", \n    \"[CLEANUP]/isolate_tmp_1/0_2.isolated\", \n    \"--path-variable\", \n    \"app_path\", \n    \"src/out/Debug-iphonesimulator/fake test 0.app\", \n    \"--config-variable\", \n    \"wpr_tools_path\", \n    \"NO_PATH\", \n    \"--config-variable\", \n    \"replay_path\", \n    \"NO_PATH\", \n    \"--config-variable\", \n    \"xcode_arg_name\", \n    \"xcode-build-version\", \n    \"--config-variable\", \n    \"xcode_version\", \n    \"9abc\", \n    \"--config-variable\", \n    \"platform\", \n    \"fake device 0\", \n    \"--config-variable\", \n    \"version\", \n    \"11.0\"\n  ], \n  \"dir\": \"[START_DIR]\", \n  \"version\": 1\n}",
+      "{\n  \"args\": [\n    \"--config-variable\", \n    \"OS\", \n    \"ios\", \n    \"--config-variable\", \n    \"app_path\", \n    \"src/out/Debug-iphonesimulator/fake test 0.app\", \n    \"--config-variable\", \n    \"restart\", \n    \"false\", \n    \"--config-variable\", \n    \"shards\", \n    \"1\", \n    \"--config-variable\", \n    \"test_args\", \n    \"[]\", \n    \"--config-variable\", \n    \"xcode_parallelization\", \n    \"false\", \n    \"--config-variable\", \n    \"test_cases\", \n    \"[\\\"ToolBarTestCase\\\"]\", \n    \"--config-variable\", \n    \"xctest\", \n    \"false\", \n    \"--config-variable\", \n    \"use_trusted_cert\", \n    \"false\", \n    \"--isolate\", \n    \"[START_DIR]/template.isolate\", \n    \"--isolated\", \n    \"[CLEANUP]/isolate_tmp_1/0_2.isolated\", \n    \"--path-variable\", \n    \"app_path\", \n    \"src/out/Debug-iphonesimulator/fake test 0.app\", \n    \"--config-variable\", \n    \"wpr_tools_path\", \n    \"NO_PATH\", \n    \"--config-variable\", \n    \"replay_path\", \n    \"NO_PATH\", \n    \"--config-variable\", \n    \"xcode_arg_name\", \n    \"xcode-build-version\", \n    \"--config-variable\", \n    \"xcode_version\", \n    \"9abc\", \n    \"--config-variable\", \n    \"platform\", \n    \"fake device 0\", \n    \"--config-variable\", \n    \"version\", \n    \"11.0\"\n  ], \n  \"dir\": \"[START_DIR]\", \n  \"version\": 1\n}",
       "[CLEANUP]/isolate_tmp_1/0_2.isolated.gen.json"
     ],
     "cwd": "[START_DIR]/src",
@@ -1028,6 +1034,9 @@
       "@@@STEP_LOG_LINE@0_2.isolated.gen.json@    \"test_args\", @@@",
       "@@@STEP_LOG_LINE@0_2.isolated.gen.json@    \"[]\", @@@",
       "@@@STEP_LOG_LINE@0_2.isolated.gen.json@    \"--config-variable\", @@@",
+      "@@@STEP_LOG_LINE@0_2.isolated.gen.json@    \"xcode_parallelization\", @@@",
+      "@@@STEP_LOG_LINE@0_2.isolated.gen.json@    \"false\", @@@",
+      "@@@STEP_LOG_LINE@0_2.isolated.gen.json@    \"--config-variable\", @@@",
       "@@@STEP_LOG_LINE@0_2.isolated.gen.json@    \"test_cases\", @@@",
       "@@@STEP_LOG_LINE@0_2.isolated.gen.json@    \"[\\\"ToolBarTestCase\\\"]\", @@@",
       "@@@STEP_LOG_LINE@0_2.isolated.gen.json@    \"--config-variable\", @@@",
@@ -1076,7 +1085,7 @@
       "--json-output",
       "/path/to/tmp/json",
       "copy",
-      "{\n  \"args\": [\n    \"--config-variable\", \n    \"OS\", \n    \"ios\", \n    \"--config-variable\", \n    \"app_path\", \n    \"src/out/Debug-iphonesimulator/fake test 1.app\", \n    \"--config-variable\", \n    \"restart\", \n    \"false\", \n    \"--config-variable\", \n    \"shards\", \n    \"1\", \n    \"--config-variable\", \n    \"test_args\", \n    \"[\\\"--fake-arg-1\\\", \\\"--fake-arg-2\\\"]\", \n    \"--config-variable\", \n    \"test_cases\", \n    \"[]\", \n    \"--config-variable\", \n    \"xctest\", \n    \"false\", \n    \"--config-variable\", \n    \"use_trusted_cert\", \n    \"false\", \n    \"--isolate\", \n    \"[START_DIR]/template.isolate\", \n    \"--isolated\", \n    \"[CLEANUP]/isolate_tmp_1/1.isolated\", \n    \"--path-variable\", \n    \"app_path\", \n    \"src/out/Debug-iphonesimulator/fake test 1.app\", \n    \"--config-variable\", \n    \"wpr_tools_path\", \n    \"NO_PATH\", \n    \"--config-variable\", \n    \"replay_path\", \n    \"NO_PATH\", \n    \"--config-variable\", \n    \"xcode_arg_name\", \n    \"xcode-build-version\", \n    \"--config-variable\", \n    \"xcode_version\", \n    \"9abc\", \n    \"--config-variable\", \n    \"platform\", \n    \"fake device 1\", \n    \"--config-variable\", \n    \"version\", \n    \"8.1\"\n  ], \n  \"dir\": \"[START_DIR]\", \n  \"version\": 1\n}",
+      "{\n  \"args\": [\n    \"--config-variable\", \n    \"OS\", \n    \"ios\", \n    \"--config-variable\", \n    \"app_path\", \n    \"src/out/Debug-iphonesimulator/fake test 1.app\", \n    \"--config-variable\", \n    \"restart\", \n    \"false\", \n    \"--config-variable\", \n    \"shards\", \n    \"1\", \n    \"--config-variable\", \n    \"test_args\", \n    \"[\\\"--fake-arg-1\\\", \\\"--fake-arg-2\\\"]\", \n    \"--config-variable\", \n    \"xcode_parallelization\", \n    \"false\", \n    \"--config-variable\", \n    \"test_cases\", \n    \"[]\", \n    \"--config-variable\", \n    \"xctest\", \n    \"false\", \n    \"--config-variable\", \n    \"use_trusted_cert\", \n    \"false\", \n    \"--isolate\", \n    \"[START_DIR]/template.isolate\", \n    \"--isolated\", \n    \"[CLEANUP]/isolate_tmp_1/1.isolated\", \n    \"--path-variable\", \n    \"app_path\", \n    \"src/out/Debug-iphonesimulator/fake test 1.app\", \n    \"--config-variable\", \n    \"wpr_tools_path\", \n    \"NO_PATH\", \n    \"--config-variable\", \n    \"replay_path\", \n    \"NO_PATH\", \n    \"--config-variable\", \n    \"xcode_arg_name\", \n    \"xcode-build-version\", \n    \"--config-variable\", \n    \"xcode_version\", \n    \"9abc\", \n    \"--config-variable\", \n    \"platform\", \n    \"fake device 1\", \n    \"--config-variable\", \n    \"version\", \n    \"8.1\"\n  ], \n  \"dir\": \"[START_DIR]\", \n  \"version\": 1\n}",
       "[CLEANUP]/isolate_tmp_1/1.isolated.gen.json"
     ],
     "cwd": "[START_DIR]/src",
@@ -1103,6 +1112,9 @@
       "@@@STEP_LOG_LINE@1.isolated.gen.json@    \"test_args\", @@@",
       "@@@STEP_LOG_LINE@1.isolated.gen.json@    \"[\\\"--fake-arg-1\\\", \\\"--fake-arg-2\\\"]\", @@@",
       "@@@STEP_LOG_LINE@1.isolated.gen.json@    \"--config-variable\", @@@",
+      "@@@STEP_LOG_LINE@1.isolated.gen.json@    \"xcode_parallelization\", @@@",
+      "@@@STEP_LOG_LINE@1.isolated.gen.json@    \"false\", @@@",
+      "@@@STEP_LOG_LINE@1.isolated.gen.json@    \"--config-variable\", @@@",
       "@@@STEP_LOG_LINE@1.isolated.gen.json@    \"test_cases\", @@@",
       "@@@STEP_LOG_LINE@1.isolated.gen.json@    \"[]\", @@@",
       "@@@STEP_LOG_LINE@1.isolated.gen.json@    \"--config-variable\", @@@",
@@ -1151,7 +1163,7 @@
       "--json-output",
       "/path/to/tmp/json",
       "copy",
-      "{\n  \"args\": [\n    \"--config-variable\", \n    \"OS\", \n    \"ios\", \n    \"--config-variable\", \n    \"app_path\", \n    \"src/out/Debug-iphonesimulator/fake test 2.app\", \n    \"--config-variable\", \n    \"restart\", \n    \"false\", \n    \"--config-variable\", \n    \"shards\", \n    \"4\", \n    \"--config-variable\", \n    \"test_args\", \n    \"[]\", \n    \"--config-variable\", \n    \"test_cases\", \n    \"[]\", \n    \"--config-variable\", \n    \"xctest\", \n    \"false\", \n    \"--config-variable\", \n    \"use_trusted_cert\", \n    \"false\", \n    \"--isolate\", \n    \"[START_DIR]/template.isolate\", \n    \"--isolated\", \n    \"[CLEANUP]/isolate_tmp_1/2.isolated\", \n    \"--path-variable\", \n    \"app_path\", \n    \"src/out/Debug-iphonesimulator/fake test 2.app\", \n    \"--config-variable\", \n    \"wpr_tools_path\", \n    \"NO_PATH\", \n    \"--config-variable\", \n    \"replay_path\", \n    \"NO_PATH\", \n    \"--config-variable\", \n    \"xcode_arg_name\", \n    \"xcode-build-version\", \n    \"--config-variable\", \n    \"xcode_version\", \n    \"9abc\", \n    \"--config-variable\", \n    \"platform\", \n    \"fake device 2\", \n    \"--config-variable\", \n    \"version\", \n    \"8.1\"\n  ], \n  \"dir\": \"[START_DIR]\", \n  \"version\": 1\n}",
+      "{\n  \"args\": [\n    \"--config-variable\", \n    \"OS\", \n    \"ios\", \n    \"--config-variable\", \n    \"app_path\", \n    \"src/out/Debug-iphonesimulator/fake test 2.app\", \n    \"--config-variable\", \n    \"restart\", \n    \"false\", \n    \"--config-variable\", \n    \"shards\", \n    \"4\", \n    \"--config-variable\", \n    \"test_args\", \n    \"[]\", \n    \"--config-variable\", \n    \"xcode_parallelization\", \n    \"false\", \n    \"--config-variable\", \n    \"test_cases\", \n    \"[]\", \n    \"--config-variable\", \n    \"xctest\", \n    \"false\", \n    \"--config-variable\", \n    \"use_trusted_cert\", \n    \"false\", \n    \"--isolate\", \n    \"[START_DIR]/template.isolate\", \n    \"--isolated\", \n    \"[CLEANUP]/isolate_tmp_1/2.isolated\", \n    \"--path-variable\", \n    \"app_path\", \n    \"src/out/Debug-iphonesimulator/fake test 2.app\", \n    \"--config-variable\", \n    \"wpr_tools_path\", \n    \"NO_PATH\", \n    \"--config-variable\", \n    \"replay_path\", \n    \"NO_PATH\", \n    \"--config-variable\", \n    \"xcode_arg_name\", \n    \"xcode-build-version\", \n    \"--config-variable\", \n    \"xcode_version\", \n    \"9abc\", \n    \"--config-variable\", \n    \"platform\", \n    \"fake device 2\", \n    \"--config-variable\", \n    \"version\", \n    \"8.1\"\n  ], \n  \"dir\": \"[START_DIR]\", \n  \"version\": 1\n}",
       "[CLEANUP]/isolate_tmp_1/2.isolated.gen.json"
     ],
     "cwd": "[START_DIR]/src",
@@ -1178,6 +1190,9 @@
       "@@@STEP_LOG_LINE@2.isolated.gen.json@    \"test_args\", @@@",
       "@@@STEP_LOG_LINE@2.isolated.gen.json@    \"[]\", @@@",
       "@@@STEP_LOG_LINE@2.isolated.gen.json@    \"--config-variable\", @@@",
+      "@@@STEP_LOG_LINE@2.isolated.gen.json@    \"xcode_parallelization\", @@@",
+      "@@@STEP_LOG_LINE@2.isolated.gen.json@    \"false\", @@@",
+      "@@@STEP_LOG_LINE@2.isolated.gen.json@    \"--config-variable\", @@@",
       "@@@STEP_LOG_LINE@2.isolated.gen.json@    \"test_cases\", @@@",
       "@@@STEP_LOG_LINE@2.isolated.gen.json@    \"[]\", @@@",
       "@@@STEP_LOG_LINE@2.isolated.gen.json@    \"--config-variable\", @@@",
@@ -1226,7 +1241,7 @@
       "--json-output",
       "/path/to/tmp/json",
       "copy",
-      "{\n  \"args\": [\n    \"--config-variable\", \n    \"OS\", \n    \"ios\", \n    \"--config-variable\", \n    \"app_path\", \n    \"src/out/Debug-iphonesimulator/fake included test 1.app\", \n    \"--config-variable\", \n    \"restart\", \n    \"false\", \n    \"--config-variable\", \n    \"shards\", \n    \"1\", \n    \"--config-variable\", \n    \"test_args\", \n    \"[]\", \n    \"--config-variable\", \n    \"test_cases\", \n    \"[]\", \n    \"--config-variable\", \n    \"xctest\", \n    \"false\", \n    \"--config-variable\", \n    \"use_trusted_cert\", \n    \"false\", \n    \"--isolate\", \n    \"[START_DIR]/template.isolate\", \n    \"--isolated\", \n    \"[CLEANUP]/isolate_tmp_1/3.isolated\", \n    \"--path-variable\", \n    \"app_path\", \n    \"src/out/Debug-iphonesimulator/fake included test 1.app\", \n    \"--config-variable\", \n    \"wpr_tools_path\", \n    \"NO_PATH\", \n    \"--config-variable\", \n    \"replay_path\", \n    \"NO_PATH\", \n    \"--config-variable\", \n    \"xcode_arg_name\", \n    \"xcode-build-version\", \n    \"--config-variable\", \n    \"xcode_version\", \n    \"9abc\", \n    \"--config-variable\", \n    \"platform\", \n    \"fake device 1\", \n    \"--config-variable\", \n    \"version\", \n    \"8.1\"\n  ], \n  \"dir\": \"[START_DIR]\", \n  \"version\": 1\n}",
+      "{\n  \"args\": [\n    \"--config-variable\", \n    \"OS\", \n    \"ios\", \n    \"--config-variable\", \n    \"app_path\", \n    \"src/out/Debug-iphonesimulator/fake included test 1.app\", \n    \"--config-variable\", \n    \"restart\", \n    \"false\", \n    \"--config-variable\", \n    \"shards\", \n    \"1\", \n    \"--config-variable\", \n    \"test_args\", \n    \"[]\", \n    \"--config-variable\", \n    \"xcode_parallelization\", \n    \"false\", \n    \"--config-variable\", \n    \"test_cases\", \n    \"[]\", \n    \"--config-variable\", \n    \"xctest\", \n    \"false\", \n    \"--config-variable\", \n    \"use_trusted_cert\", \n    \"false\", \n    \"--isolate\", \n    \"[START_DIR]/template.isolate\", \n    \"--isolated\", \n    \"[CLEANUP]/isolate_tmp_1/3.isolated\", \n    \"--path-variable\", \n    \"app_path\", \n    \"src/out/Debug-iphonesimulator/fake included test 1.app\", \n    \"--config-variable\", \n    \"wpr_tools_path\", \n    \"NO_PATH\", \n    \"--config-variable\", \n    \"replay_path\", \n    \"NO_PATH\", \n    \"--config-variable\", \n    \"xcode_arg_name\", \n    \"xcode-build-version\", \n    \"--config-variable\", \n    \"xcode_version\", \n    \"9abc\", \n    \"--config-variable\", \n    \"platform\", \n    \"fake device 1\", \n    \"--config-variable\", \n    \"version\", \n    \"8.1\"\n  ], \n  \"dir\": \"[START_DIR]\", \n  \"version\": 1\n}",
       "[CLEANUP]/isolate_tmp_1/3.isolated.gen.json"
     ],
     "cwd": "[START_DIR]/src",
@@ -1253,6 +1268,9 @@
       "@@@STEP_LOG_LINE@3.isolated.gen.json@    \"test_args\", @@@",
       "@@@STEP_LOG_LINE@3.isolated.gen.json@    \"[]\", @@@",
       "@@@STEP_LOG_LINE@3.isolated.gen.json@    \"--config-variable\", @@@",
+      "@@@STEP_LOG_LINE@3.isolated.gen.json@    \"xcode_parallelization\", @@@",
+      "@@@STEP_LOG_LINE@3.isolated.gen.json@    \"false\", @@@",
+      "@@@STEP_LOG_LINE@3.isolated.gen.json@    \"--config-variable\", @@@",
       "@@@STEP_LOG_LINE@3.isolated.gen.json@    \"test_cases\", @@@",
       "@@@STEP_LOG_LINE@3.isolated.gen.json@    \"[]\", @@@",
       "@@@STEP_LOG_LINE@3.isolated.gen.json@    \"--config-variable\", @@@",
@@ -1301,7 +1319,7 @@
       "--json-output",
       "/path/to/tmp/json",
       "copy",
-      "{\n  \"args\": [\n    \"--config-variable\", \n    \"OS\", \n    \"ios\", \n    \"--config-variable\", \n    \"app_path\", \n    \"src/out/Debug-iphonesimulator/fake included test 2.app\", \n    \"--config-variable\", \n    \"restart\", \n    \"false\", \n    \"--config-variable\", \n    \"shards\", \n    \"1\", \n    \"--config-variable\", \n    \"test_args\", \n    \"[]\", \n    \"--config-variable\", \n    \"test_cases\", \n    \"[]\", \n    \"--config-variable\", \n    \"xctest\", \n    \"false\", \n    \"--config-variable\", \n    \"use_trusted_cert\", \n    \"false\", \n    \"--isolate\", \n    \"[START_DIR]/template.isolate\", \n    \"--isolated\", \n    \"[CLEANUP]/isolate_tmp_1/4.isolated\", \n    \"--path-variable\", \n    \"app_path\", \n    \"src/out/Debug-iphonesimulator/fake included test 2.app\", \n    \"--config-variable\", \n    \"wpr_tools_path\", \n    \"NO_PATH\", \n    \"--config-variable\", \n    \"replay_path\", \n    \"NO_PATH\", \n    \"--config-variable\", \n    \"xcode_arg_name\", \n    \"xcode-build-version\", \n    \"--config-variable\", \n    \"xcode_version\", \n    \"9abc\", \n    \"--config-variable\", \n    \"platform\", \n    \"fake device 1\", \n    \"--config-variable\", \n    \"version\", \n    \"8.1\"\n  ], \n  \"dir\": \"[START_DIR]\", \n  \"version\": 1\n}",
+      "{\n  \"args\": [\n    \"--config-variable\", \n    \"OS\", \n    \"ios\", \n    \"--config-variable\", \n    \"app_path\", \n    \"src/out/Debug-iphonesimulator/fake included test 2.app\", \n    \"--config-variable\", \n    \"restart\", \n    \"false\", \n    \"--config-variable\", \n    \"shards\", \n    \"1\", \n    \"--config-variable\", \n    \"test_args\", \n    \"[]\", \n    \"--config-variable\", \n    \"xcode_parallelization\", \n    \"false\", \n    \"--config-variable\", \n    \"test_cases\", \n    \"[]\", \n    \"--config-variable\", \n    \"xctest\", \n    \"false\", \n    \"--config-variable\", \n    \"use_trusted_cert\", \n    \"false\", \n    \"--isolate\", \n    \"[START_DIR]/template.isolate\", \n    \"--isolated\", \n    \"[CLEANUP]/isolate_tmp_1/4.isolated\", \n    \"--path-variable\", \n    \"app_path\", \n    \"src/out/Debug-iphonesimulator/fake included test 2.app\", \n    \"--config-variable\", \n    \"wpr_tools_path\", \n    \"NO_PATH\", \n    \"--config-variable\", \n    \"replay_path\", \n    \"NO_PATH\", \n    \"--config-variable\", \n    \"xcode_arg_name\", \n    \"xcode-build-version\", \n    \"--config-variable\", \n    \"xcode_version\", \n    \"9abc\", \n    \"--config-variable\", \n    \"platform\", \n    \"fake device 1\", \n    \"--config-variable\", \n    \"version\", \n    \"8.1\"\n  ], \n  \"dir\": \"[START_DIR]\", \n  \"version\": 1\n}",
       "[CLEANUP]/isolate_tmp_1/4.isolated.gen.json"
     ],
     "cwd": "[START_DIR]/src",
@@ -1328,6 +1346,9 @@
       "@@@STEP_LOG_LINE@4.isolated.gen.json@    \"test_args\", @@@",
       "@@@STEP_LOG_LINE@4.isolated.gen.json@    \"[]\", @@@",
       "@@@STEP_LOG_LINE@4.isolated.gen.json@    \"--config-variable\", @@@",
+      "@@@STEP_LOG_LINE@4.isolated.gen.json@    \"xcode_parallelization\", @@@",
+      "@@@STEP_LOG_LINE@4.isolated.gen.json@    \"false\", @@@",
+      "@@@STEP_LOG_LINE@4.isolated.gen.json@    \"--config-variable\", @@@",
       "@@@STEP_LOG_LINE@4.isolated.gen.json@    \"test_cases\", @@@",
       "@@@STEP_LOG_LINE@4.isolated.gen.json@    \"[]\", @@@",
       "@@@STEP_LOG_LINE@4.isolated.gen.json@    \"--config-variable\", @@@",
@@ -1376,7 +1397,7 @@
       "--json-output",
       "/path/to/tmp/json",
       "copy",
-      "{\n  \"args\": [\n    \"--config-variable\", \n    \"OS\", \n    \"ios\", \n    \"--config-variable\", \n    \"app_path\", \n    \"src/out/Debug-iphonesimulator/fake test 2.app\", \n    \"--config-variable\", \n    \"restart\", \n    \"false\", \n    \"--config-variable\", \n    \"shards\", \n    \"1\", \n    \"--config-variable\", \n    \"test_args\", \n    \"[]\", \n    \"--config-variable\", \n    \"test_cases\", \n    \"[]\", \n    \"--config-variable\", \n    \"xctest\", \n    \"false\", \n    \"--config-variable\", \n    \"use_trusted_cert\", \n    \"false\", \n    \"--isolate\", \n    \"[START_DIR]/template.isolate\", \n    \"--isolated\", \n    \"[CLEANUP]/isolate_tmp_1/5.isolated\", \n    \"--path-variable\", \n    \"app_path\", \n    \"src/out/Debug-iphonesimulator/fake test 2.app\", \n    \"--config-variable\", \n    \"wpr_tools_path\", \n    \"NO_PATH\", \n    \"--config-variable\", \n    \"replay_path\", \n    \"NO_PATH\", \n    \"--config-variable\", \n    \"xcode_arg_name\", \n    \"xcode-build-version\", \n    \"--config-variable\", \n    \"xcode_version\", \n    \"9abc\", \n    \"--config-variable\", \n    \"platform\", \n    \"fake device 2\", \n    \"--config-variable\", \n    \"version\", \n    \"7.1\"\n  ], \n  \"dir\": \"[START_DIR]\", \n  \"version\": 1\n}",
+      "{\n  \"args\": [\n    \"--config-variable\", \n    \"OS\", \n    \"ios\", \n    \"--config-variable\", \n    \"app_path\", \n    \"src/out/Debug-iphonesimulator/fake test 2.app\", \n    \"--config-variable\", \n    \"restart\", \n    \"false\", \n    \"--config-variable\", \n    \"shards\", \n    \"1\", \n    \"--config-variable\", \n    \"test_args\", \n    \"[]\", \n    \"--config-variable\", \n    \"xcode_parallelization\", \n    \"false\", \n    \"--config-variable\", \n    \"test_cases\", \n    \"[]\", \n    \"--config-variable\", \n    \"xctest\", \n    \"false\", \n    \"--config-variable\", \n    \"use_trusted_cert\", \n    \"false\", \n    \"--isolate\", \n    \"[START_DIR]/template.isolate\", \n    \"--isolated\", \n    \"[CLEANUP]/isolate_tmp_1/5.isolated\", \n    \"--path-variable\", \n    \"app_path\", \n    \"src/out/Debug-iphonesimulator/fake test 2.app\", \n    \"--config-variable\", \n    \"wpr_tools_path\", \n    \"NO_PATH\", \n    \"--config-variable\", \n    \"replay_path\", \n    \"NO_PATH\", \n    \"--config-variable\", \n    \"xcode_arg_name\", \n    \"xcode-build-version\", \n    \"--config-variable\", \n    \"xcode_version\", \n    \"9abc\", \n    \"--config-variable\", \n    \"platform\", \n    \"fake device 2\", \n    \"--config-variable\", \n    \"version\", \n    \"7.1\"\n  ], \n  \"dir\": \"[START_DIR]\", \n  \"version\": 1\n}",
       "[CLEANUP]/isolate_tmp_1/5.isolated.gen.json"
     ],
     "cwd": "[START_DIR]/src",
@@ -1403,6 +1424,9 @@
       "@@@STEP_LOG_LINE@5.isolated.gen.json@    \"test_args\", @@@",
       "@@@STEP_LOG_LINE@5.isolated.gen.json@    \"[]\", @@@",
       "@@@STEP_LOG_LINE@5.isolated.gen.json@    \"--config-variable\", @@@",
+      "@@@STEP_LOG_LINE@5.isolated.gen.json@    \"xcode_parallelization\", @@@",
+      "@@@STEP_LOG_LINE@5.isolated.gen.json@    \"false\", @@@",
+      "@@@STEP_LOG_LINE@5.isolated.gen.json@    \"--config-variable\", @@@",
       "@@@STEP_LOG_LINE@5.isolated.gen.json@    \"test_cases\", @@@",
       "@@@STEP_LOG_LINE@5.isolated.gen.json@    \"[]\", @@@",
       "@@@STEP_LOG_LINE@5.isolated.gen.json@    \"--config-variable\", @@@",
@@ -1451,7 +1475,7 @@
       "--json-output",
       "/path/to/tmp/json",
       "copy",
-      "{\n  \"args\": [\n    \"--config-variable\", \n    \"OS\", \n    \"ios\", \n    \"--config-variable\", \n    \"app_path\", \n    \"src/out/Debug-iphonesimulator/fake included test 1.app\", \n    \"--config-variable\", \n    \"restart\", \n    \"false\", \n    \"--config-variable\", \n    \"shards\", \n    \"1\", \n    \"--config-variable\", \n    \"test_args\", \n    \"[]\", \n    \"--config-variable\", \n    \"test_cases\", \n    \"[]\", \n    \"--config-variable\", \n    \"xctest\", \n    \"false\", \n    \"--config-variable\", \n    \"use_trusted_cert\", \n    \"false\", \n    \"--isolate\", \n    \"[START_DIR]/template.isolate\", \n    \"--isolated\", \n    \"[CLEANUP]/isolate_tmp_1/6.isolated\", \n    \"--path-variable\", \n    \"app_path\", \n    \"src/out/Debug-iphonesimulator/fake included test 1.app\", \n    \"--config-variable\", \n    \"wpr_tools_path\", \n    \"NO_PATH\", \n    \"--config-variable\", \n    \"replay_path\", \n    \"NO_PATH\", \n    \"--config-variable\", \n    \"xcode_arg_name\", \n    \"xcode-build-version\", \n    \"--config-variable\", \n    \"xcode_version\", \n    \"9abc\", \n    \"--config-variable\", \n    \"platform\", \n    \"fake device 2\", \n    \"--config-variable\", \n    \"version\", \n    \"7.1\"\n  ], \n  \"dir\": \"[START_DIR]\", \n  \"version\": 1\n}",
+      "{\n  \"args\": [\n    \"--config-variable\", \n    \"OS\", \n    \"ios\", \n    \"--config-variable\", \n    \"app_path\", \n    \"src/out/Debug-iphonesimulator/fake included test 1.app\", \n    \"--config-variable\", \n    \"restart\", \n    \"false\", \n    \"--config-variable\", \n    \"shards\", \n    \"1\", \n    \"--config-variable\", \n    \"test_args\", \n    \"[]\", \n    \"--config-variable\", \n    \"xcode_parallelization\", \n    \"false\", \n    \"--config-variable\", \n    \"test_cases\", \n    \"[]\", \n    \"--config-variable\", \n    \"xctest\", \n    \"false\", \n    \"--config-variable\", \n    \"use_trusted_cert\", \n    \"false\", \n    \"--isolate\", \n    \"[START_DIR]/template.isolate\", \n    \"--isolated\", \n    \"[CLEANUP]/isolate_tmp_1/6.isolated\", \n    \"--path-variable\", \n    \"app_path\", \n    \"src/out/Debug-iphonesimulator/fake included test 1.app\", \n    \"--config-variable\", \n    \"wpr_tools_path\", \n    \"NO_PATH\", \n    \"--config-variable\", \n    \"replay_path\", \n    \"NO_PATH\", \n    \"--config-variable\", \n    \"xcode_arg_name\", \n    \"xcode-build-version\", \n    \"--config-variable\", \n    \"xcode_version\", \n    \"9abc\", \n    \"--config-variable\", \n    \"platform\", \n    \"fake device 2\", \n    \"--config-variable\", \n    \"version\", \n    \"7.1\"\n  ], \n  \"dir\": \"[START_DIR]\", \n  \"version\": 1\n}",
       "[CLEANUP]/isolate_tmp_1/6.isolated.gen.json"
     ],
     "cwd": "[START_DIR]/src",
@@ -1478,6 +1502,9 @@
       "@@@STEP_LOG_LINE@6.isolated.gen.json@    \"test_args\", @@@",
       "@@@STEP_LOG_LINE@6.isolated.gen.json@    \"[]\", @@@",
       "@@@STEP_LOG_LINE@6.isolated.gen.json@    \"--config-variable\", @@@",
+      "@@@STEP_LOG_LINE@6.isolated.gen.json@    \"xcode_parallelization\", @@@",
+      "@@@STEP_LOG_LINE@6.isolated.gen.json@    \"false\", @@@",
+      "@@@STEP_LOG_LINE@6.isolated.gen.json@    \"--config-variable\", @@@",
       "@@@STEP_LOG_LINE@6.isolated.gen.json@    \"test_cases\", @@@",
       "@@@STEP_LOG_LINE@6.isolated.gen.json@    \"[]\", @@@",
       "@@@STEP_LOG_LINE@6.isolated.gen.json@    \"--config-variable\", @@@",
@@ -1526,7 +1553,7 @@
       "--json-output",
       "/path/to/tmp/json",
       "copy",
-      "{\n  \"args\": [\n    \"--config-variable\", \n    \"OS\", \n    \"ios\", \n    \"--config-variable\", \n    \"app_path\", \n    \"src/out/Debug-iphonesimulator/fake included test 2.app\", \n    \"--config-variable\", \n    \"restart\", \n    \"false\", \n    \"--config-variable\", \n    \"shards\", \n    \"1\", \n    \"--config-variable\", \n    \"test_args\", \n    \"[]\", \n    \"--config-variable\", \n    \"test_cases\", \n    \"[]\", \n    \"--config-variable\", \n    \"xctest\", \n    \"false\", \n    \"--config-variable\", \n    \"use_trusted_cert\", \n    \"false\", \n    \"--isolate\", \n    \"[START_DIR]/template.isolate\", \n    \"--isolated\", \n    \"[CLEANUP]/isolate_tmp_1/7.isolated\", \n    \"--path-variable\", \n    \"app_path\", \n    \"src/out/Debug-iphonesimulator/fake included test 2.app\", \n    \"--config-variable\", \n    \"wpr_tools_path\", \n    \"NO_PATH\", \n    \"--config-variable\", \n    \"replay_path\", \n    \"NO_PATH\", \n    \"--config-variable\", \n    \"xcode_arg_name\", \n    \"xcode-build-version\", \n    \"--config-variable\", \n    \"xcode_version\", \n    \"9abc\", \n    \"--config-variable\", \n    \"platform\", \n    \"fake device 2\", \n    \"--config-variable\", \n    \"version\", \n    \"7.1\"\n  ], \n  \"dir\": \"[START_DIR]\", \n  \"version\": 1\n}",
+      "{\n  \"args\": [\n    \"--config-variable\", \n    \"OS\", \n    \"ios\", \n    \"--config-variable\", \n    \"app_path\", \n    \"src/out/Debug-iphonesimulator/fake included test 2.app\", \n    \"--config-variable\", \n    \"restart\", \n    \"false\", \n    \"--config-variable\", \n    \"shards\", \n    \"1\", \n    \"--config-variable\", \n    \"test_args\", \n    \"[]\", \n    \"--config-variable\", \n    \"xcode_parallelization\", \n    \"false\", \n    \"--config-variable\", \n    \"test_cases\", \n    \"[]\", \n    \"--config-variable\", \n    \"xctest\", \n    \"false\", \n    \"--config-variable\", \n    \"use_trusted_cert\", \n    \"false\", \n    \"--isolate\", \n    \"[START_DIR]/template.isolate\", \n    \"--isolated\", \n    \"[CLEANUP]/isolate_tmp_1/7.isolated\", \n    \"--path-variable\", \n    \"app_path\", \n    \"src/out/Debug-iphonesimulator/fake included test 2.app\", \n    \"--config-variable\", \n    \"wpr_tools_path\", \n    \"NO_PATH\", \n    \"--config-variable\", \n    \"replay_path\", \n    \"NO_PATH\", \n    \"--config-variable\", \n    \"xcode_arg_name\", \n    \"xcode-build-version\", \n    \"--config-variable\", \n    \"xcode_version\", \n    \"9abc\", \n    \"--config-variable\", \n    \"platform\", \n    \"fake device 2\", \n    \"--config-variable\", \n    \"version\", \n    \"7.1\"\n  ], \n  \"dir\": \"[START_DIR]\", \n  \"version\": 1\n}",
       "[CLEANUP]/isolate_tmp_1/7.isolated.gen.json"
     ],
     "cwd": "[START_DIR]/src",
@@ -1553,6 +1580,9 @@
       "@@@STEP_LOG_LINE@7.isolated.gen.json@    \"test_args\", @@@",
       "@@@STEP_LOG_LINE@7.isolated.gen.json@    \"[]\", @@@",
       "@@@STEP_LOG_LINE@7.isolated.gen.json@    \"--config-variable\", @@@",
+      "@@@STEP_LOG_LINE@7.isolated.gen.json@    \"xcode_parallelization\", @@@",
+      "@@@STEP_LOG_LINE@7.isolated.gen.json@    \"false\", @@@",
+      "@@@STEP_LOG_LINE@7.isolated.gen.json@    \"--config-variable\", @@@",
       "@@@STEP_LOG_LINE@7.isolated.gen.json@    \"test_cases\", @@@",
       "@@@STEP_LOG_LINE@7.isolated.gen.json@    \"[]\", @@@",
       "@@@STEP_LOG_LINE@7.isolated.gen.json@    \"--config-variable\", @@@",
@@ -1601,7 +1631,7 @@
       "--json-output",
       "/path/to/tmp/json",
       "copy",
-      "{\n  \"args\": [\n    \"--config-variable\", \n    \"OS\", \n    \"ios\", \n    \"--config-variable\", \n    \"app_path\", \n    \"src/out/Debug-iphonesimulator/fake child test 1.app\", \n    \"--config-variable\", \n    \"restart\", \n    \"false\", \n    \"--config-variable\", \n    \"shards\", \n    \"1\", \n    \"--config-variable\", \n    \"test_args\", \n    \"[]\", \n    \"--config-variable\", \n    \"test_cases\", \n    \"[]\", \n    \"--config-variable\", \n    \"xctest\", \n    \"false\", \n    \"--config-variable\", \n    \"use_trusted_cert\", \n    \"false\", \n    \"--isolate\", \n    \"[START_DIR]/template.isolate\", \n    \"--isolated\", \n    \"[CLEANUP]/isolate_tmp_1/8.isolated\", \n    \"--path-variable\", \n    \"app_path\", \n    \"src/out/Debug-iphonesimulator/fake child test 1.app\", \n    \"--config-variable\", \n    \"wpr_tools_path\", \n    \"NO_PATH\", \n    \"--config-variable\", \n    \"replay_path\", \n    \"NO_PATH\", \n    \"--config-variable\", \n    \"xcode_arg_name\", \n    \"xcode-build-version\", \n    \"--config-variable\", \n    \"xcode_version\", \n    \"9abc\", \n    \"--config-variable\", \n    \"platform\", \n    \"fake child device 1\", \n    \"--config-variable\", \n    \"version\", \n    \"8.1\"\n  ], \n  \"dir\": \"[START_DIR]\", \n  \"version\": 1\n}",
+      "{\n  \"args\": [\n    \"--config-variable\", \n    \"OS\", \n    \"ios\", \n    \"--config-variable\", \n    \"app_path\", \n    \"src/out/Debug-iphonesimulator/fake child test 1.app\", \n    \"--config-variable\", \n    \"restart\", \n    \"false\", \n    \"--config-variable\", \n    \"shards\", \n    \"1\", \n    \"--config-variable\", \n    \"test_args\", \n    \"[]\", \n    \"--config-variable\", \n    \"xcode_parallelization\", \n    \"false\", \n    \"--config-variable\", \n    \"test_cases\", \n    \"[]\", \n    \"--config-variable\", \n    \"xctest\", \n    \"false\", \n    \"--config-variable\", \n    \"use_trusted_cert\", \n    \"false\", \n    \"--isolate\", \n    \"[START_DIR]/template.isolate\", \n    \"--isolated\", \n    \"[CLEANUP]/isolate_tmp_1/8.isolated\", \n    \"--path-variable\", \n    \"app_path\", \n    \"src/out/Debug-iphonesimulator/fake child test 1.app\", \n    \"--config-variable\", \n    \"wpr_tools_path\", \n    \"NO_PATH\", \n    \"--config-variable\", \n    \"replay_path\", \n    \"NO_PATH\", \n    \"--config-variable\", \n    \"xcode_arg_name\", \n    \"xcode-build-version\", \n    \"--config-variable\", \n    \"xcode_version\", \n    \"9abc\", \n    \"--config-variable\", \n    \"platform\", \n    \"fake child device 1\", \n    \"--config-variable\", \n    \"version\", \n    \"8.1\"\n  ], \n  \"dir\": \"[START_DIR]\", \n  \"version\": 1\n}",
       "[CLEANUP]/isolate_tmp_1/8.isolated.gen.json"
     ],
     "cwd": "[START_DIR]/src",
@@ -1628,6 +1658,9 @@
       "@@@STEP_LOG_LINE@8.isolated.gen.json@    \"test_args\", @@@",
       "@@@STEP_LOG_LINE@8.isolated.gen.json@    \"[]\", @@@",
       "@@@STEP_LOG_LINE@8.isolated.gen.json@    \"--config-variable\", @@@",
+      "@@@STEP_LOG_LINE@8.isolated.gen.json@    \"xcode_parallelization\", @@@",
+      "@@@STEP_LOG_LINE@8.isolated.gen.json@    \"false\", @@@",
+      "@@@STEP_LOG_LINE@8.isolated.gen.json@    \"--config-variable\", @@@",
       "@@@STEP_LOG_LINE@8.isolated.gen.json@    \"test_cases\", @@@",
       "@@@STEP_LOG_LINE@8.isolated.gen.json@    \"[]\", @@@",
       "@@@STEP_LOG_LINE@8.isolated.gen.json@    \"--config-variable\", @@@",
@@ -1676,7 +1709,7 @@
       "--json-output",
       "/path/to/tmp/json",
       "copy",
-      "{\n  \"args\": [\n    \"--config-variable\", \n    \"OS\", \n    \"ios\", \n    \"--config-variable\", \n    \"app_path\", \n    \"src/out/Debug-iphonesimulator/fake included test 1.app\", \n    \"--config-variable\", \n    \"restart\", \n    \"false\", \n    \"--config-variable\", \n    \"shards\", \n    \"1\", \n    \"--config-variable\", \n    \"test_args\", \n    \"[]\", \n    \"--config-variable\", \n    \"test_cases\", \n    \"[]\", \n    \"--config-variable\", \n    \"xctest\", \n    \"false\", \n    \"--config-variable\", \n    \"use_trusted_cert\", \n    \"false\", \n    \"--isolate\", \n    \"[START_DIR]/template.isolate\", \n    \"--isolated\", \n    \"[CLEANUP]/isolate_tmp_1/9.isolated\", \n    \"--path-variable\", \n    \"app_path\", \n    \"src/out/Debug-iphonesimulator/fake included test 1.app\", \n    \"--config-variable\", \n    \"wpr_tools_path\", \n    \"NO_PATH\", \n    \"--config-variable\", \n    \"replay_path\", \n    \"NO_PATH\", \n    \"--config-variable\", \n    \"xcode_arg_name\", \n    \"xcode-build-version\", \n    \"--config-variable\", \n    \"xcode_version\", \n    \"9abc\", \n    \"--config-variable\", \n    \"platform\", \n    \"fake child device 2\", \n    \"--config-variable\", \n    \"version\", \n    \"9.0\"\n  ], \n  \"dir\": \"[START_DIR]\", \n  \"version\": 1\n}",
+      "{\n  \"args\": [\n    \"--config-variable\", \n    \"OS\", \n    \"ios\", \n    \"--config-variable\", \n    \"app_path\", \n    \"src/out/Debug-iphonesimulator/fake included test 1.app\", \n    \"--config-variable\", \n    \"restart\", \n    \"false\", \n    \"--config-variable\", \n    \"shards\", \n    \"1\", \n    \"--config-variable\", \n    \"test_args\", \n    \"[]\", \n    \"--config-variable\", \n    \"xcode_parallelization\", \n    \"false\", \n    \"--config-variable\", \n    \"test_cases\", \n    \"[]\", \n    \"--config-variable\", \n    \"xctest\", \n    \"false\", \n    \"--config-variable\", \n    \"use_trusted_cert\", \n    \"false\", \n    \"--isolate\", \n    \"[START_DIR]/template.isolate\", \n    \"--isolated\", \n    \"[CLEANUP]/isolate_tmp_1/9.isolated\", \n    \"--path-variable\", \n    \"app_path\", \n    \"src/out/Debug-iphonesimulator/fake included test 1.app\", \n    \"--config-variable\", \n    \"wpr_tools_path\", \n    \"NO_PATH\", \n    \"--config-variable\", \n    \"replay_path\", \n    \"NO_PATH\", \n    \"--config-variable\", \n    \"xcode_arg_name\", \n    \"xcode-build-version\", \n    \"--config-variable\", \n    \"xcode_version\", \n    \"9abc\", \n    \"--config-variable\", \n    \"platform\", \n    \"fake child device 2\", \n    \"--config-variable\", \n    \"version\", \n    \"9.0\"\n  ], \n  \"dir\": \"[START_DIR]\", \n  \"version\": 1\n}",
       "[CLEANUP]/isolate_tmp_1/9.isolated.gen.json"
     ],
     "cwd": "[START_DIR]/src",
@@ -1703,6 +1736,9 @@
       "@@@STEP_LOG_LINE@9.isolated.gen.json@    \"test_args\", @@@",
       "@@@STEP_LOG_LINE@9.isolated.gen.json@    \"[]\", @@@",
       "@@@STEP_LOG_LINE@9.isolated.gen.json@    \"--config-variable\", @@@",
+      "@@@STEP_LOG_LINE@9.isolated.gen.json@    \"xcode_parallelization\", @@@",
+      "@@@STEP_LOG_LINE@9.isolated.gen.json@    \"false\", @@@",
+      "@@@STEP_LOG_LINE@9.isolated.gen.json@    \"--config-variable\", @@@",
       "@@@STEP_LOG_LINE@9.isolated.gen.json@    \"test_cases\", @@@",
       "@@@STEP_LOG_LINE@9.isolated.gen.json@    \"[]\", @@@",
       "@@@STEP_LOG_LINE@9.isolated.gen.json@    \"--config-variable\", @@@",
@@ -1751,7 +1787,7 @@
       "--json-output",
       "/path/to/tmp/json",
       "copy",
-      "{\n  \"args\": [\n    \"--config-variable\", \n    \"OS\", \n    \"ios\", \n    \"--config-variable\", \n    \"app_path\", \n    \"src/out/Debug-iphonesimulator/fake included test 2.app\", \n    \"--config-variable\", \n    \"restart\", \n    \"false\", \n    \"--config-variable\", \n    \"shards\", \n    \"1\", \n    \"--config-variable\", \n    \"test_args\", \n    \"[]\", \n    \"--config-variable\", \n    \"test_cases\", \n    \"[]\", \n    \"--config-variable\", \n    \"xctest\", \n    \"false\", \n    \"--config-variable\", \n    \"use_trusted_cert\", \n    \"false\", \n    \"--isolate\", \n    \"[START_DIR]/template.isolate\", \n    \"--isolated\", \n    \"[CLEANUP]/isolate_tmp_1/10.isolated\", \n    \"--path-variable\", \n    \"app_path\", \n    \"src/out/Debug-iphonesimulator/fake included test 2.app\", \n    \"--config-variable\", \n    \"wpr_tools_path\", \n    \"NO_PATH\", \n    \"--config-variable\", \n    \"replay_path\", \n    \"NO_PATH\", \n    \"--config-variable\", \n    \"xcode_arg_name\", \n    \"xcode-build-version\", \n    \"--config-variable\", \n    \"xcode_version\", \n    \"9abc\", \n    \"--config-variable\", \n    \"platform\", \n    \"fake child device 2\", \n    \"--config-variable\", \n    \"version\", \n    \"9.0\"\n  ], \n  \"dir\": \"[START_DIR]\", \n  \"version\": 1\n}",
+      "{\n  \"args\": [\n    \"--config-variable\", \n    \"OS\", \n    \"ios\", \n    \"--config-variable\", \n    \"app_path\", \n    \"src/out/Debug-iphonesimulator/fake included test 2.app\", \n    \"--config-variable\", \n    \"restart\", \n    \"false\", \n    \"--config-variable\", \n    \"shards\", \n    \"1\", \n    \"--config-variable\", \n    \"test_args\", \n    \"[]\", \n    \"--config-variable\", \n    \"xcode_parallelization\", \n    \"false\", \n    \"--config-variable\", \n    \"test_cases\", \n    \"[]\", \n    \"--config-variable\", \n    \"xctest\", \n    \"false\", \n    \"--config-variable\", \n    \"use_trusted_cert\", \n    \"false\", \n    \"--isolate\", \n    \"[START_DIR]/template.isolate\", \n    \"--isolated\", \n    \"[CLEANUP]/isolate_tmp_1/10.isolated\", \n    \"--path-variable\", \n    \"app_path\", \n    \"src/out/Debug-iphonesimulator/fake included test 2.app\", \n    \"--config-variable\", \n    \"wpr_tools_path\", \n    \"NO_PATH\", \n    \"--config-variable\", \n    \"replay_path\", \n    \"NO_PATH\", \n    \"--config-variable\", \n    \"xcode_arg_name\", \n    \"xcode-build-version\", \n    \"--config-variable\", \n    \"xcode_version\", \n    \"9abc\", \n    \"--config-variable\", \n    \"platform\", \n    \"fake child device 2\", \n    \"--config-variable\", \n    \"version\", \n    \"9.0\"\n  ], \n  \"dir\": \"[START_DIR]\", \n  \"version\": 1\n}",
       "[CLEANUP]/isolate_tmp_1/10.isolated.gen.json"
     ],
     "cwd": "[START_DIR]/src",
@@ -1778,6 +1814,9 @@
       "@@@STEP_LOG_LINE@10.isolated.gen.json@    \"test_args\", @@@",
       "@@@STEP_LOG_LINE@10.isolated.gen.json@    \"[]\", @@@",
       "@@@STEP_LOG_LINE@10.isolated.gen.json@    \"--config-variable\", @@@",
+      "@@@STEP_LOG_LINE@10.isolated.gen.json@    \"xcode_parallelization\", @@@",
+      "@@@STEP_LOG_LINE@10.isolated.gen.json@    \"false\", @@@",
+      "@@@STEP_LOG_LINE@10.isolated.gen.json@    \"--config-variable\", @@@",
       "@@@STEP_LOG_LINE@10.isolated.gen.json@    \"test_cases\", @@@",
       "@@@STEP_LOG_LINE@10.isolated.gen.json@    \"[]\", @@@",
       "@@@STEP_LOG_LINE@10.isolated.gen.json@    \"--config-variable\", @@@",
diff --git a/scripts/slave/recipe_modules/ios/examples/full.expected/clobber_build.json b/scripts/slave/recipe_modules/ios/examples/full.expected/clobber_build.json
index 0657521..2752362 100644
--- a/scripts/slave/recipe_modules/ios/examples/full.expected/clobber_build.json
+++ b/scripts/slave/recipe_modules/ios/examples/full.expected/clobber_build.json
@@ -370,7 +370,7 @@
       "--json-output",
       "/path/to/tmp/json",
       "copy",
-      "{'conditions': [['OS == \"ios\"', {'variables': {'files': ['<(app_path)/', 'src/ios/build/bots/scripts/', 'src/out/Debug-iphonesimulator/iossim'], 'command': ['src/ios/build/bots/scripts/run.py', '--app', '<(app_path)', '--args-json', '{\"test_args\": <(test_args),         \"xctest\": <(xctest),         \"test_cases\": <(test_cases),         \"restart\": <(restart)}', '--out-dir', '${ISOLATED_OUTDIR}', '--retries', '3', '--shards', '<(shards)', '--<(xcode_arg_name)', '<(xcode_version)', '--mac-toolchain-cmd', './mac_toolchain', '--xcode-path', 'Xcode.app', '--wpr-tools-path', '<(wpr_tools_path)', '--replay-path', '<(replay_path)', '--iossim', 'src/out/Debug-iphonesimulator/iossim', '--platform', '<(platform)', '--version', '<(version)']}}]]}",
+      "{'conditions': [['OS == \"ios\"', {'variables': {'files': ['<(app_path)/', 'src/ios/build/bots/scripts/', 'src/out/Debug-iphonesimulator/iossim'], 'command': ['src/ios/build/bots/scripts/run.py', '--app', '<(app_path)', '--args-json', '{\"test_args\": <(test_args),         \"xctest\": <(xctest),         \"test_cases\": <(test_cases),         \"restart\": <(restart),         \"xcode-parallelization\": <(xcode_parallelization)}', '--out-dir', '${ISOLATED_OUTDIR}', '--retries', '3', '--shards', '<(shards)', '--<(xcode_arg_name)', '<(xcode_version)', '--mac-toolchain-cmd', './mac_toolchain', '--xcode-path', 'Xcode.app', '--wpr-tools-path', '<(wpr_tools_path)', '--replay-path', '<(replay_path)', '--iossim', 'src/out/Debug-iphonesimulator/iossim', '--platform', '<(platform)', '--version', '<(version)']}}]]}",
       "[START_DIR]/template.isolate"
     ],
     "cwd": "[START_DIR]/src",
@@ -389,7 +389,7 @@
       "@@@STEP_LOG_LINE@template.isolate@            \"--app\", @@@",
       "@@@STEP_LOG_LINE@template.isolate@            \"<(app_path)\", @@@",
       "@@@STEP_LOG_LINE@template.isolate@            \"--args-json\", @@@",
-      "@@@STEP_LOG_LINE@template.isolate@            \"{\\\"test_args\\\": <(test_args),         \\\"xctest\\\": <(xctest),         \\\"test_cases\\\": <(test_cases),         \\\"restart\\\": <(restart)}\", @@@",
+      "@@@STEP_LOG_LINE@template.isolate@            \"{\\\"test_args\\\": <(test_args),         \\\"xctest\\\": <(xctest),         \\\"test_cases\\\": <(test_cases),         \\\"restart\\\": <(restart),         \\\"xcode-parallelization\\\": <(xcode_parallelization)}\", @@@",
       "@@@STEP_LOG_LINE@template.isolate@            \"--out-dir\", @@@",
       "@@@STEP_LOG_LINE@template.isolate@            \"${ISOLATED_OUTDIR}\", @@@",
       "@@@STEP_LOG_LINE@template.isolate@            \"--retries\", @@@",
diff --git a/scripts/slave/recipe_modules/ios/examples/full.expected/clobber_checkout.json b/scripts/slave/recipe_modules/ios/examples/full.expected/clobber_checkout.json
index 2fb4803..266c243 100644
--- a/scripts/slave/recipe_modules/ios/examples/full.expected/clobber_checkout.json
+++ b/scripts/slave/recipe_modules/ios/examples/full.expected/clobber_checkout.json
@@ -369,7 +369,7 @@
       "--json-output",
       "/path/to/tmp/json",
       "copy",
-      "{'conditions': [['OS == \"ios\"', {'variables': {'files': ['<(app_path)/', 'src/ios/build/bots/scripts/', 'src/out/Debug-iphonesimulator/iossim'], 'command': ['src/ios/build/bots/scripts/run.py', '--app', '<(app_path)', '--args-json', '{\"test_args\": <(test_args),         \"xctest\": <(xctest),         \"test_cases\": <(test_cases),         \"restart\": <(restart)}', '--out-dir', '${ISOLATED_OUTDIR}', '--retries', '3', '--shards', '<(shards)', '--<(xcode_arg_name)', '<(xcode_version)', '--mac-toolchain-cmd', './mac_toolchain', '--xcode-path', 'Xcode.app', '--wpr-tools-path', '<(wpr_tools_path)', '--replay-path', '<(replay_path)', '--iossim', 'src/out/Debug-iphonesimulator/iossim', '--platform', '<(platform)', '--version', '<(version)']}}]]}",
+      "{'conditions': [['OS == \"ios\"', {'variables': {'files': ['<(app_path)/', 'src/ios/build/bots/scripts/', 'src/out/Debug-iphonesimulator/iossim'], 'command': ['src/ios/build/bots/scripts/run.py', '--app', '<(app_path)', '--args-json', '{\"test_args\": <(test_args),         \"xctest\": <(xctest),         \"test_cases\": <(test_cases),         \"restart\": <(restart),         \"xcode-parallelization\": <(xcode_parallelization)}', '--out-dir', '${ISOLATED_OUTDIR}', '--retries', '3', '--shards', '<(shards)', '--<(xcode_arg_name)', '<(xcode_version)', '--mac-toolchain-cmd', './mac_toolchain', '--xcode-path', 'Xcode.app', '--wpr-tools-path', '<(wpr_tools_path)', '--replay-path', '<(replay_path)', '--iossim', 'src/out/Debug-iphonesimulator/iossim', '--platform', '<(platform)', '--version', '<(version)']}}]]}",
       "[START_DIR]/template.isolate"
     ],
     "cwd": "[START_DIR]/src",
@@ -388,7 +388,7 @@
       "@@@STEP_LOG_LINE@template.isolate@            \"--app\", @@@",
       "@@@STEP_LOG_LINE@template.isolate@            \"<(app_path)\", @@@",
       "@@@STEP_LOG_LINE@template.isolate@            \"--args-json\", @@@",
-      "@@@STEP_LOG_LINE@template.isolate@            \"{\\\"test_args\\\": <(test_args),         \\\"xctest\\\": <(xctest),         \\\"test_cases\\\": <(test_cases),         \\\"restart\\\": <(restart)}\", @@@",
+      "@@@STEP_LOG_LINE@template.isolate@            \"{\\\"test_args\\\": <(test_args),         \\\"xctest\\\": <(xctest),         \\\"test_cases\\\": <(test_cases),         \\\"restart\\\": <(restart),         \\\"xcode-parallelization\\\": <(xcode_parallelization)}\", @@@",
       "@@@STEP_LOG_LINE@template.isolate@            \"--out-dir\", @@@",
       "@@@STEP_LOG_LINE@template.isolate@            \"${ISOLATED_OUTDIR}\", @@@",
       "@@@STEP_LOG_LINE@template.isolate@            \"--retries\", @@@",
diff --git a/scripts/slave/recipe_modules/ios/examples/full.expected/deprecate_xcode_version.json b/scripts/slave/recipe_modules/ios/examples/full.expected/deprecate_xcode_version.json
index 75bc1f1..457fff6 100644
--- a/scripts/slave/recipe_modules/ios/examples/full.expected/deprecate_xcode_version.json
+++ b/scripts/slave/recipe_modules/ios/examples/full.expected/deprecate_xcode_version.json
@@ -379,7 +379,7 @@
       "--json-output",
       "/path/to/tmp/json",
       "copy",
-      "{'conditions': [['OS == \"ios\"', {'variables': {'files': ['<(app_path)/', 'src/ios/build/bots/scripts/'], 'command': ['src/ios/build/bots/scripts/run.py', '--app', '<(app_path)', '--args-json', '{\"test_args\": <(test_args),         \"xctest\": <(xctest),         \"test_cases\": <(test_cases),         \"restart\": <(restart)}', '--out-dir', '${ISOLATED_OUTDIR}', '--retries', '3', '--shards', '<(shards)', '--<(xcode_arg_name)', '<(xcode_version)', '--mac-toolchain-cmd', './mac_toolchain', '--xcode-path', 'Xcode.app', '--wpr-tools-path', '<(wpr_tools_path)', '--replay-path', '<(replay_path)']}}]]}",
+      "{'conditions': [['OS == \"ios\"', {'variables': {'files': ['<(app_path)/', 'src/ios/build/bots/scripts/'], 'command': ['src/ios/build/bots/scripts/run.py', '--app', '<(app_path)', '--args-json', '{\"test_args\": <(test_args),         \"xctest\": <(xctest),         \"test_cases\": <(test_cases),         \"restart\": <(restart),         \"xcode-parallelization\": <(xcode_parallelization)}', '--out-dir', '${ISOLATED_OUTDIR}', '--retries', '3', '--shards', '<(shards)', '--<(xcode_arg_name)', '<(xcode_version)', '--mac-toolchain-cmd', './mac_toolchain', '--xcode-path', 'Xcode.app', '--wpr-tools-path', '<(wpr_tools_path)', '--replay-path', '<(replay_path)']}}]]}",
       "[START_DIR]/template.isolate"
     ],
     "cwd": "[START_DIR]/src",
@@ -398,7 +398,7 @@
       "@@@STEP_LOG_LINE@template.isolate@            \"--app\", @@@",
       "@@@STEP_LOG_LINE@template.isolate@            \"<(app_path)\", @@@",
       "@@@STEP_LOG_LINE@template.isolate@            \"--args-json\", @@@",
-      "@@@STEP_LOG_LINE@template.isolate@            \"{\\\"test_args\\\": <(test_args),         \\\"xctest\\\": <(xctest),         \\\"test_cases\\\": <(test_cases),         \\\"restart\\\": <(restart)}\", @@@",
+      "@@@STEP_LOG_LINE@template.isolate@            \"{\\\"test_args\\\": <(test_args),         \\\"xctest\\\": <(xctest),         \\\"test_cases\\\": <(test_cases),         \\\"restart\\\": <(restart),         \\\"xcode-parallelization\\\": <(xcode_parallelization)}\", @@@",
       "@@@STEP_LOG_LINE@template.isolate@            \"--out-dir\", @@@",
       "@@@STEP_LOG_LINE@template.isolate@            \"${ISOLATED_OUTDIR}\", @@@",
       "@@@STEP_LOG_LINE@template.isolate@            \"--retries\", @@@",
@@ -436,7 +436,7 @@
       "--json-output",
       "/path/to/tmp/json",
       "copy",
-      "{\n  \"args\": [\n    \"--config-variable\", \n    \"OS\", \n    \"ios\", \n    \"--config-variable\", \n    \"app_path\", \n    \"src/out/Debug-iphoneos/build-global xcode version.app\", \n    \"--config-variable\", \n    \"restart\", \n    \"false\", \n    \"--config-variable\", \n    \"shards\", \n    \"1\", \n    \"--config-variable\", \n    \"test_args\", \n    \"[]\", \n    \"--config-variable\", \n    \"test_cases\", \n    \"[]\", \n    \"--config-variable\", \n    \"xctest\", \n    \"false\", \n    \"--config-variable\", \n    \"use_trusted_cert\", \n    \"false\", \n    \"--isolate\", \n    \"[START_DIR]/template.isolate\", \n    \"--isolated\", \n    \"[CLEANUP]/isolate_tmp_1/0.isolated\", \n    \"--path-variable\", \n    \"app_path\", \n    \"src/out/Debug-iphoneos/build-global xcode version.app\", \n    \"--config-variable\", \n    \"wpr_tools_path\", \n    \"NO_PATH\", \n    \"--config-variable\", \n    \"replay_path\", \n    \"NO_PATH\", \n    \"--config-variable\", \n    \"xcode_arg_name\", \n    \"xcode-build-version\", \n    \"--config-variable\", \n    \"xcode_version\", \n    \"8a218a\"\n  ], \n  \"dir\": \"[START_DIR]\", \n  \"version\": 1\n}",
+      "{\n  \"args\": [\n    \"--config-variable\", \n    \"OS\", \n    \"ios\", \n    \"--config-variable\", \n    \"app_path\", \n    \"src/out/Debug-iphoneos/build-global xcode version.app\", \n    \"--config-variable\", \n    \"restart\", \n    \"false\", \n    \"--config-variable\", \n    \"shards\", \n    \"1\", \n    \"--config-variable\", \n    \"test_args\", \n    \"[]\", \n    \"--config-variable\", \n    \"xcode_parallelization\", \n    \"false\", \n    \"--config-variable\", \n    \"test_cases\", \n    \"[]\", \n    \"--config-variable\", \n    \"xctest\", \n    \"false\", \n    \"--config-variable\", \n    \"use_trusted_cert\", \n    \"false\", \n    \"--isolate\", \n    \"[START_DIR]/template.isolate\", \n    \"--isolated\", \n    \"[CLEANUP]/isolate_tmp_1/0.isolated\", \n    \"--path-variable\", \n    \"app_path\", \n    \"src/out/Debug-iphoneos/build-global xcode version.app\", \n    \"--config-variable\", \n    \"wpr_tools_path\", \n    \"NO_PATH\", \n    \"--config-variable\", \n    \"replay_path\", \n    \"NO_PATH\", \n    \"--config-variable\", \n    \"xcode_arg_name\", \n    \"xcode-build-version\", \n    \"--config-variable\", \n    \"xcode_version\", \n    \"8a218a\"\n  ], \n  \"dir\": \"[START_DIR]\", \n  \"version\": 1\n}",
       "[CLEANUP]/isolate_tmp_1/0.isolated.gen.json"
     ],
     "cwd": "[START_DIR]/src",
@@ -463,6 +463,9 @@
       "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"test_args\", @@@",
       "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"[]\", @@@",
       "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"--config-variable\", @@@",
+      "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"xcode_parallelization\", @@@",
+      "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"false\", @@@",
+      "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"--config-variable\", @@@",
       "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"test_cases\", @@@",
       "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"[]\", @@@",
       "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"--config-variable\", @@@",
@@ -515,7 +518,7 @@
       "--json-output",
       "/path/to/tmp/json",
       "copy",
-      "{\n  \"args\": [\n    \"--config-variable\", \n    \"OS\", \n    \"ios\", \n    \"--config-variable\", \n    \"app_path\", \n    \"src/out/Debug-iphoneos/test-local xcode version.app\", \n    \"--config-variable\", \n    \"restart\", \n    \"false\", \n    \"--config-variable\", \n    \"shards\", \n    \"1\", \n    \"--config-variable\", \n    \"test_args\", \n    \"[]\", \n    \"--config-variable\", \n    \"test_cases\", \n    \"[]\", \n    \"--config-variable\", \n    \"xctest\", \n    \"false\", \n    \"--config-variable\", \n    \"use_trusted_cert\", \n    \"false\", \n    \"--isolate\", \n    \"[START_DIR]/template.isolate\", \n    \"--isolated\", \n    \"[CLEANUP]/isolate_tmp_1/1.isolated\", \n    \"--path-variable\", \n    \"app_path\", \n    \"src/out/Debug-iphoneos/test-local xcode version.app\", \n    \"--config-variable\", \n    \"wpr_tools_path\", \n    \"NO_PATH\", \n    \"--config-variable\", \n    \"replay_path\", \n    \"NO_PATH\", \n    \"--config-variable\", \n    \"xcode_arg_name\", \n    \"xcode-build-version\", \n    \"--config-variable\", \n    \"xcode_version\", \n    \"9a235\"\n  ], \n  \"dir\": \"[START_DIR]\", \n  \"version\": 1\n}",
+      "{\n  \"args\": [\n    \"--config-variable\", \n    \"OS\", \n    \"ios\", \n    \"--config-variable\", \n    \"app_path\", \n    \"src/out/Debug-iphoneos/test-local xcode version.app\", \n    \"--config-variable\", \n    \"restart\", \n    \"false\", \n    \"--config-variable\", \n    \"shards\", \n    \"1\", \n    \"--config-variable\", \n    \"test_args\", \n    \"[]\", \n    \"--config-variable\", \n    \"xcode_parallelization\", \n    \"false\", \n    \"--config-variable\", \n    \"test_cases\", \n    \"[]\", \n    \"--config-variable\", \n    \"xctest\", \n    \"false\", \n    \"--config-variable\", \n    \"use_trusted_cert\", \n    \"false\", \n    \"--isolate\", \n    \"[START_DIR]/template.isolate\", \n    \"--isolated\", \n    \"[CLEANUP]/isolate_tmp_1/1.isolated\", \n    \"--path-variable\", \n    \"app_path\", \n    \"src/out/Debug-iphoneos/test-local xcode version.app\", \n    \"--config-variable\", \n    \"wpr_tools_path\", \n    \"NO_PATH\", \n    \"--config-variable\", \n    \"replay_path\", \n    \"NO_PATH\", \n    \"--config-variable\", \n    \"xcode_arg_name\", \n    \"xcode-build-version\", \n    \"--config-variable\", \n    \"xcode_version\", \n    \"9a235\"\n  ], \n  \"dir\": \"[START_DIR]\", \n  \"version\": 1\n}",
       "[CLEANUP]/isolate_tmp_1/1.isolated.gen.json"
     ],
     "cwd": "[START_DIR]/src",
@@ -542,6 +545,9 @@
       "@@@STEP_LOG_LINE@1.isolated.gen.json@    \"test_args\", @@@",
       "@@@STEP_LOG_LINE@1.isolated.gen.json@    \"[]\", @@@",
       "@@@STEP_LOG_LINE@1.isolated.gen.json@    \"--config-variable\", @@@",
+      "@@@STEP_LOG_LINE@1.isolated.gen.json@    \"xcode_parallelization\", @@@",
+      "@@@STEP_LOG_LINE@1.isolated.gen.json@    \"false\", @@@",
+      "@@@STEP_LOG_LINE@1.isolated.gen.json@    \"--config-variable\", @@@",
       "@@@STEP_LOG_LINE@1.isolated.gen.json@    \"test_cases\", @@@",
       "@@@STEP_LOG_LINE@1.isolated.gen.json@    \"[]\", @@@",
       "@@@STEP_LOG_LINE@1.isolated.gen.json@    \"--config-variable\", @@@",
diff --git a/scripts/slave/recipe_modules/ios/examples/full.expected/device_check_false.json b/scripts/slave/recipe_modules/ios/examples/full.expected/device_check_false.json
index bb0b586..0aea187 100644
--- a/scripts/slave/recipe_modules/ios/examples/full.expected/device_check_false.json
+++ b/scripts/slave/recipe_modules/ios/examples/full.expected/device_check_false.json
@@ -364,7 +364,7 @@
       "--json-output",
       "/path/to/tmp/json",
       "copy",
-      "{'conditions': [['OS == \"ios\"', {'variables': {'files': ['<(app_path)/', 'src/ios/build/bots/scripts/'], 'command': ['src/ios/build/bots/scripts/run.py', '--app', '<(app_path)', '--args-json', '{\"test_args\": <(test_args),         \"xctest\": <(xctest),         \"test_cases\": <(test_cases),         \"restart\": <(restart)}', '--out-dir', '${ISOLATED_OUTDIR}', '--retries', '3', '--shards', '<(shards)', '--<(xcode_arg_name)', '<(xcode_version)', '--mac-toolchain-cmd', './mac_toolchain', '--xcode-path', 'Xcode.app', '--wpr-tools-path', '<(wpr_tools_path)', '--replay-path', '<(replay_path)']}}]]}",
+      "{'conditions': [['OS == \"ios\"', {'variables': {'files': ['<(app_path)/', 'src/ios/build/bots/scripts/'], 'command': ['src/ios/build/bots/scripts/run.py', '--app', '<(app_path)', '--args-json', '{\"test_args\": <(test_args),         \"xctest\": <(xctest),         \"test_cases\": <(test_cases),         \"restart\": <(restart),         \"xcode-parallelization\": <(xcode_parallelization)}', '--out-dir', '${ISOLATED_OUTDIR}', '--retries', '3', '--shards', '<(shards)', '--<(xcode_arg_name)', '<(xcode_version)', '--mac-toolchain-cmd', './mac_toolchain', '--xcode-path', 'Xcode.app', '--wpr-tools-path', '<(wpr_tools_path)', '--replay-path', '<(replay_path)']}}]]}",
       "[START_DIR]/template.isolate"
     ],
     "cwd": "[START_DIR]/src",
@@ -383,7 +383,7 @@
       "@@@STEP_LOG_LINE@template.isolate@            \"--app\", @@@",
       "@@@STEP_LOG_LINE@template.isolate@            \"<(app_path)\", @@@",
       "@@@STEP_LOG_LINE@template.isolate@            \"--args-json\", @@@",
-      "@@@STEP_LOG_LINE@template.isolate@            \"{\\\"test_args\\\": <(test_args),         \\\"xctest\\\": <(xctest),         \\\"test_cases\\\": <(test_cases),         \\\"restart\\\": <(restart)}\", @@@",
+      "@@@STEP_LOG_LINE@template.isolate@            \"{\\\"test_args\\\": <(test_args),         \\\"xctest\\\": <(xctest),         \\\"test_cases\\\": <(test_cases),         \\\"restart\\\": <(restart),         \\\"xcode-parallelization\\\": <(xcode_parallelization)}\", @@@",
       "@@@STEP_LOG_LINE@template.isolate@            \"--out-dir\", @@@",
       "@@@STEP_LOG_LINE@template.isolate@            \"${ISOLATED_OUTDIR}\", @@@",
       "@@@STEP_LOG_LINE@template.isolate@            \"--retries\", @@@",
@@ -421,7 +421,7 @@
       "--json-output",
       "/path/to/tmp/json",
       "copy",
-      "{\n  \"args\": [\n    \"--config-variable\", \n    \"OS\", \n    \"ios\", \n    \"--config-variable\", \n    \"app_path\", \n    \"src/out/Debug-iphoneos/build-global xcode build version.app\", \n    \"--config-variable\", \n    \"restart\", \n    \"false\", \n    \"--config-variable\", \n    \"shards\", \n    \"1\", \n    \"--config-variable\", \n    \"test_args\", \n    \"[]\", \n    \"--config-variable\", \n    \"test_cases\", \n    \"[]\", \n    \"--config-variable\", \n    \"xctest\", \n    \"false\", \n    \"--config-variable\", \n    \"use_trusted_cert\", \n    \"false\", \n    \"--isolate\", \n    \"[START_DIR]/template.isolate\", \n    \"--isolated\", \n    \"[CLEANUP]/isolate_tmp_1/0.isolated\", \n    \"--path-variable\", \n    \"app_path\", \n    \"src/out/Debug-iphoneos/build-global xcode build version.app\", \n    \"--config-variable\", \n    \"wpr_tools_path\", \n    \"NO_PATH\", \n    \"--config-variable\", \n    \"replay_path\", \n    \"NO_PATH\", \n    \"--config-variable\", \n    \"xcode_arg_name\", \n    \"xcode-build-version\", \n    \"--config-variable\", \n    \"xcode_version\", \n    \"9a123\"\n  ], \n  \"dir\": \"[START_DIR]\", \n  \"version\": 1\n}",
+      "{\n  \"args\": [\n    \"--config-variable\", \n    \"OS\", \n    \"ios\", \n    \"--config-variable\", \n    \"app_path\", \n    \"src/out/Debug-iphoneos/build-global xcode build version.app\", \n    \"--config-variable\", \n    \"restart\", \n    \"false\", \n    \"--config-variable\", \n    \"shards\", \n    \"1\", \n    \"--config-variable\", \n    \"test_args\", \n    \"[]\", \n    \"--config-variable\", \n    \"xcode_parallelization\", \n    \"false\", \n    \"--config-variable\", \n    \"test_cases\", \n    \"[]\", \n    \"--config-variable\", \n    \"xctest\", \n    \"false\", \n    \"--config-variable\", \n    \"use_trusted_cert\", \n    \"false\", \n    \"--isolate\", \n    \"[START_DIR]/template.isolate\", \n    \"--isolated\", \n    \"[CLEANUP]/isolate_tmp_1/0.isolated\", \n    \"--path-variable\", \n    \"app_path\", \n    \"src/out/Debug-iphoneos/build-global xcode build version.app\", \n    \"--config-variable\", \n    \"wpr_tools_path\", \n    \"NO_PATH\", \n    \"--config-variable\", \n    \"replay_path\", \n    \"NO_PATH\", \n    \"--config-variable\", \n    \"xcode_arg_name\", \n    \"xcode-build-version\", \n    \"--config-variable\", \n    \"xcode_version\", \n    \"9a123\"\n  ], \n  \"dir\": \"[START_DIR]\", \n  \"version\": 1\n}",
       "[CLEANUP]/isolate_tmp_1/0.isolated.gen.json"
     ],
     "cwd": "[START_DIR]/src",
@@ -448,6 +448,9 @@
       "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"test_args\", @@@",
       "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"[]\", @@@",
       "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"--config-variable\", @@@",
+      "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"xcode_parallelization\", @@@",
+      "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"false\", @@@",
+      "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"--config-variable\", @@@",
       "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"test_cases\", @@@",
       "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"[]\", @@@",
       "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"--config-variable\", @@@",
diff --git a/scripts/slave/recipe_modules/ios/examples/full.expected/errors.json b/scripts/slave/recipe_modules/ios/examples/full.expected/errors.json
index fc6b72c..59a017e 100644
--- a/scripts/slave/recipe_modules/ios/examples/full.expected/errors.json
+++ b/scripts/slave/recipe_modules/ios/examples/full.expected/errors.json
@@ -381,7 +381,7 @@
       "--json-output",
       "/path/to/tmp/json",
       "copy",
-      "{'conditions': [['OS == \"ios\"', {'variables': {'files': ['<(app_path)/', 'src/ios/build/bots/scripts/'], 'command': ['src/ios/build/bots/scripts/run.py', '--app', '<(app_path)', '--args-json', '{\"test_args\": <(test_args),         \"xctest\": <(xctest),         \"test_cases\": <(test_cases),         \"restart\": <(restart)}', '--out-dir', '${ISOLATED_OUTDIR}', '--retries', '3', '--shards', '<(shards)', '--<(xcode_arg_name)', '<(xcode_version)', '--mac-toolchain-cmd', './mac_toolchain', '--xcode-path', 'Xcode.app', '--wpr-tools-path', '<(wpr_tools_path)', '--replay-path', '<(replay_path)']}}]]}",
+      "{'conditions': [['OS == \"ios\"', {'variables': {'files': ['<(app_path)/', 'src/ios/build/bots/scripts/'], 'command': ['src/ios/build/bots/scripts/run.py', '--app', '<(app_path)', '--args-json', '{\"test_args\": <(test_args),         \"xctest\": <(xctest),         \"test_cases\": <(test_cases),         \"restart\": <(restart),         \"xcode-parallelization\": <(xcode_parallelization)}', '--out-dir', '${ISOLATED_OUTDIR}', '--retries', '3', '--shards', '<(shards)', '--<(xcode_arg_name)', '<(xcode_version)', '--mac-toolchain-cmd', './mac_toolchain', '--xcode-path', 'Xcode.app', '--wpr-tools-path', '<(wpr_tools_path)', '--replay-path', '<(replay_path)']}}]]}",
       "[START_DIR]/template.isolate"
     ],
     "cwd": "[START_DIR]/src",
@@ -400,7 +400,7 @@
       "@@@STEP_LOG_LINE@template.isolate@            \"--app\", @@@",
       "@@@STEP_LOG_LINE@template.isolate@            \"<(app_path)\", @@@",
       "@@@STEP_LOG_LINE@template.isolate@            \"--args-json\", @@@",
-      "@@@STEP_LOG_LINE@template.isolate@            \"{\\\"test_args\\\": <(test_args),         \\\"xctest\\\": <(xctest),         \\\"test_cases\\\": <(test_cases),         \\\"restart\\\": <(restart)}\", @@@",
+      "@@@STEP_LOG_LINE@template.isolate@            \"{\\\"test_args\\\": <(test_args),         \\\"xctest\\\": <(xctest),         \\\"test_cases\\\": <(test_cases),         \\\"restart\\\": <(restart),         \\\"xcode-parallelization\\\": <(xcode_parallelization)}\", @@@",
       "@@@STEP_LOG_LINE@template.isolate@            \"--out-dir\", @@@",
       "@@@STEP_LOG_LINE@template.isolate@            \"${ISOLATED_OUTDIR}\", @@@",
       "@@@STEP_LOG_LINE@template.isolate@            \"--retries\", @@@",
@@ -438,7 +438,7 @@
       "--json-output",
       "/path/to/tmp/json",
       "copy",
-      "{\n  \"args\": [\n    \"--config-variable\", \n    \"OS\", \n    \"ios\", \n    \"--config-variable\", \n    \"app_path\", \n    \"src/out/Release-iphoneos/fake test 1.app\", \n    \"--config-variable\", \n    \"restart\", \n    \"false\", \n    \"--config-variable\", \n    \"shards\", \n    \"1\", \n    \"--config-variable\", \n    \"test_args\", \n    \"[]\", \n    \"--config-variable\", \n    \"test_cases\", \n    \"[]\", \n    \"--config-variable\", \n    \"xctest\", \n    \"false\", \n    \"--config-variable\", \n    \"use_trusted_cert\", \n    \"false\", \n    \"--isolate\", \n    \"[START_DIR]/template.isolate\", \n    \"--isolated\", \n    \"[CLEANUP]/isolate_tmp_1/0.isolated\", \n    \"--path-variable\", \n    \"app_path\", \n    \"src/out/Release-iphoneos/fake test 1.app\", \n    \"--config-variable\", \n    \"wpr_tools_path\", \n    \"NO_PATH\", \n    \"--config-variable\", \n    \"replay_path\", \n    \"NO_PATH\", \n    \"--config-variable\", \n    \"xcode_arg_name\", \n    \"xcode-build-version\", \n    \"--config-variable\", \n    \"xcode_version\", \n    \"9abc\"\n  ], \n  \"dir\": \"[START_DIR]\", \n  \"version\": 1\n}",
+      "{\n  \"args\": [\n    \"--config-variable\", \n    \"OS\", \n    \"ios\", \n    \"--config-variable\", \n    \"app_path\", \n    \"src/out/Release-iphoneos/fake test 1.app\", \n    \"--config-variable\", \n    \"restart\", \n    \"false\", \n    \"--config-variable\", \n    \"shards\", \n    \"1\", \n    \"--config-variable\", \n    \"test_args\", \n    \"[]\", \n    \"--config-variable\", \n    \"xcode_parallelization\", \n    \"false\", \n    \"--config-variable\", \n    \"test_cases\", \n    \"[]\", \n    \"--config-variable\", \n    \"xctest\", \n    \"false\", \n    \"--config-variable\", \n    \"use_trusted_cert\", \n    \"false\", \n    \"--isolate\", \n    \"[START_DIR]/template.isolate\", \n    \"--isolated\", \n    \"[CLEANUP]/isolate_tmp_1/0.isolated\", \n    \"--path-variable\", \n    \"app_path\", \n    \"src/out/Release-iphoneos/fake test 1.app\", \n    \"--config-variable\", \n    \"wpr_tools_path\", \n    \"NO_PATH\", \n    \"--config-variable\", \n    \"replay_path\", \n    \"NO_PATH\", \n    \"--config-variable\", \n    \"xcode_arg_name\", \n    \"xcode-build-version\", \n    \"--config-variable\", \n    \"xcode_version\", \n    \"9abc\"\n  ], \n  \"dir\": \"[START_DIR]\", \n  \"version\": 1\n}",
       "[CLEANUP]/isolate_tmp_1/0.isolated.gen.json"
     ],
     "cwd": "[START_DIR]/src",
@@ -458,7 +458,7 @@
       "--json-output",
       "/path/to/tmp/json",
       "copy",
-      "{\n  \"args\": [\n    \"--config-variable\", \n    \"OS\", \n    \"ios\", \n    \"--config-variable\", \n    \"app_path\", \n    \"src/out/Release-iphoneos/fake test 2.app\", \n    \"--config-variable\", \n    \"restart\", \n    \"false\", \n    \"--config-variable\", \n    \"shards\", \n    \"1\", \n    \"--config-variable\", \n    \"test_args\", \n    \"[]\", \n    \"--config-variable\", \n    \"test_cases\", \n    \"[]\", \n    \"--config-variable\", \n    \"xctest\", \n    \"false\", \n    \"--config-variable\", \n    \"use_trusted_cert\", \n    \"false\", \n    \"--isolate\", \n    \"[START_DIR]/template.isolate\", \n    \"--isolated\", \n    \"[CLEANUP]/isolate_tmp_1/1.isolated\", \n    \"--path-variable\", \n    \"app_path\", \n    \"src/out/Release-iphoneos/fake test 2.app\", \n    \"--config-variable\", \n    \"wpr_tools_path\", \n    \"NO_PATH\", \n    \"--config-variable\", \n    \"replay_path\", \n    \"NO_PATH\", \n    \"--config-variable\", \n    \"xcode_arg_name\", \n    \"xcode-build-version\", \n    \"--config-variable\", \n    \"xcode_version\", \n    \"9abc\"\n  ], \n  \"dir\": \"[START_DIR]\", \n  \"version\": 1\n}",
+      "{\n  \"args\": [\n    \"--config-variable\", \n    \"OS\", \n    \"ios\", \n    \"--config-variable\", \n    \"app_path\", \n    \"src/out/Release-iphoneos/fake test 2.app\", \n    \"--config-variable\", \n    \"restart\", \n    \"false\", \n    \"--config-variable\", \n    \"shards\", \n    \"1\", \n    \"--config-variable\", \n    \"test_args\", \n    \"[]\", \n    \"--config-variable\", \n    \"xcode_parallelization\", \n    \"false\", \n    \"--config-variable\", \n    \"test_cases\", \n    \"[]\", \n    \"--config-variable\", \n    \"xctest\", \n    \"false\", \n    \"--config-variable\", \n    \"use_trusted_cert\", \n    \"false\", \n    \"--isolate\", \n    \"[START_DIR]/template.isolate\", \n    \"--isolated\", \n    \"[CLEANUP]/isolate_tmp_1/1.isolated\", \n    \"--path-variable\", \n    \"app_path\", \n    \"src/out/Release-iphoneos/fake test 2.app\", \n    \"--config-variable\", \n    \"wpr_tools_path\", \n    \"NO_PATH\", \n    \"--config-variable\", \n    \"replay_path\", \n    \"NO_PATH\", \n    \"--config-variable\", \n    \"xcode_arg_name\", \n    \"xcode-build-version\", \n    \"--config-variable\", \n    \"xcode_version\", \n    \"9abc\"\n  ], \n  \"dir\": \"[START_DIR]\", \n  \"version\": 1\n}",
       "[CLEANUP]/isolate_tmp_1/1.isolated.gen.json"
     ],
     "cwd": "[START_DIR]/src",
@@ -485,6 +485,9 @@
       "@@@STEP_LOG_LINE@1.isolated.gen.json@    \"test_args\", @@@",
       "@@@STEP_LOG_LINE@1.isolated.gen.json@    \"[]\", @@@",
       "@@@STEP_LOG_LINE@1.isolated.gen.json@    \"--config-variable\", @@@",
+      "@@@STEP_LOG_LINE@1.isolated.gen.json@    \"xcode_parallelization\", @@@",
+      "@@@STEP_LOG_LINE@1.isolated.gen.json@    \"false\", @@@",
+      "@@@STEP_LOG_LINE@1.isolated.gen.json@    \"--config-variable\", @@@",
       "@@@STEP_LOG_LINE@1.isolated.gen.json@    \"test_cases\", @@@",
       "@@@STEP_LOG_LINE@1.isolated.gen.json@    \"[]\", @@@",
       "@@@STEP_LOG_LINE@1.isolated.gen.json@    \"--config-variable\", @@@",
@@ -527,7 +530,7 @@
       "--json-output",
       "/path/to/tmp/json",
       "copy",
-      "{\n  \"args\": [\n    \"--config-variable\", \n    \"OS\", \n    \"ios\", \n    \"--config-variable\", \n    \"app_path\", \n    \"src/out/Release-iphoneos/fake test 3.app\", \n    \"--config-variable\", \n    \"restart\", \n    \"false\", \n    \"--config-variable\", \n    \"shards\", \n    \"1\", \n    \"--config-variable\", \n    \"test_args\", \n    \"[]\", \n    \"--config-variable\", \n    \"test_cases\", \n    \"[]\", \n    \"--config-variable\", \n    \"xctest\", \n    \"false\", \n    \"--config-variable\", \n    \"use_trusted_cert\", \n    \"false\", \n    \"--isolate\", \n    \"[START_DIR]/template.isolate\", \n    \"--isolated\", \n    \"[CLEANUP]/isolate_tmp_1/2.isolated\", \n    \"--path-variable\", \n    \"app_path\", \n    \"src/out/Release-iphoneos/fake test 3.app\", \n    \"--config-variable\", \n    \"wpr_tools_path\", \n    \"NO_PATH\", \n    \"--config-variable\", \n    \"replay_path\", \n    \"NO_PATH\", \n    \"--config-variable\", \n    \"xcode_arg_name\", \n    \"xcode-build-version\", \n    \"--config-variable\", \n    \"xcode_version\", \n    \"9abc\"\n  ], \n  \"dir\": \"[START_DIR]\", \n  \"version\": 1\n}",
+      "{\n  \"args\": [\n    \"--config-variable\", \n    \"OS\", \n    \"ios\", \n    \"--config-variable\", \n    \"app_path\", \n    \"src/out/Release-iphoneos/fake test 3.app\", \n    \"--config-variable\", \n    \"restart\", \n    \"false\", \n    \"--config-variable\", \n    \"shards\", \n    \"1\", \n    \"--config-variable\", \n    \"test_args\", \n    \"[]\", \n    \"--config-variable\", \n    \"xcode_parallelization\", \n    \"false\", \n    \"--config-variable\", \n    \"test_cases\", \n    \"[]\", \n    \"--config-variable\", \n    \"xctest\", \n    \"false\", \n    \"--config-variable\", \n    \"use_trusted_cert\", \n    \"false\", \n    \"--isolate\", \n    \"[START_DIR]/template.isolate\", \n    \"--isolated\", \n    \"[CLEANUP]/isolate_tmp_1/2.isolated\", \n    \"--path-variable\", \n    \"app_path\", \n    \"src/out/Release-iphoneos/fake test 3.app\", \n    \"--config-variable\", \n    \"wpr_tools_path\", \n    \"NO_PATH\", \n    \"--config-variable\", \n    \"replay_path\", \n    \"NO_PATH\", \n    \"--config-variable\", \n    \"xcode_arg_name\", \n    \"xcode-build-version\", \n    \"--config-variable\", \n    \"xcode_version\", \n    \"9abc\"\n  ], \n  \"dir\": \"[START_DIR]\", \n  \"version\": 1\n}",
       "[CLEANUP]/isolate_tmp_1/2.isolated.gen.json"
     ],
     "cwd": "[START_DIR]/src",
@@ -554,6 +557,9 @@
       "@@@STEP_LOG_LINE@2.isolated.gen.json@    \"test_args\", @@@",
       "@@@STEP_LOG_LINE@2.isolated.gen.json@    \"[]\", @@@",
       "@@@STEP_LOG_LINE@2.isolated.gen.json@    \"--config-variable\", @@@",
+      "@@@STEP_LOG_LINE@2.isolated.gen.json@    \"xcode_parallelization\", @@@",
+      "@@@STEP_LOG_LINE@2.isolated.gen.json@    \"false\", @@@",
+      "@@@STEP_LOG_LINE@2.isolated.gen.json@    \"--config-variable\", @@@",
       "@@@STEP_LOG_LINE@2.isolated.gen.json@    \"test_cases\", @@@",
       "@@@STEP_LOG_LINE@2.isolated.gen.json@    \"[]\", @@@",
       "@@@STEP_LOG_LINE@2.isolated.gen.json@    \"--config-variable\", @@@",
@@ -596,7 +602,7 @@
       "--json-output",
       "/path/to/tmp/json",
       "copy",
-      "{\n  \"args\": [\n    \"--config-variable\", \n    \"OS\", \n    \"ios\", \n    \"--config-variable\", \n    \"app_path\", \n    \"src/out/Release-iphoneos/fake test 4.app\", \n    \"--config-variable\", \n    \"restart\", \n    \"false\", \n    \"--config-variable\", \n    \"shards\", \n    \"1\", \n    \"--config-variable\", \n    \"test_args\", \n    \"[]\", \n    \"--config-variable\", \n    \"test_cases\", \n    \"[]\", \n    \"--config-variable\", \n    \"xctest\", \n    \"false\", \n    \"--config-variable\", \n    \"use_trusted_cert\", \n    \"false\", \n    \"--isolate\", \n    \"[START_DIR]/template.isolate\", \n    \"--isolated\", \n    \"[CLEANUP]/isolate_tmp_1/3.isolated\", \n    \"--path-variable\", \n    \"app_path\", \n    \"src/out/Release-iphoneos/fake test 4.app\", \n    \"--config-variable\", \n    \"wpr_tools_path\", \n    \"NO_PATH\", \n    \"--config-variable\", \n    \"replay_path\", \n    \"NO_PATH\", \n    \"--config-variable\", \n    \"xcode_arg_name\", \n    \"xcode-build-version\", \n    \"--config-variable\", \n    \"xcode_version\", \n    \"9abc\"\n  ], \n  \"dir\": \"[START_DIR]\", \n  \"version\": 1\n}",
+      "{\n  \"args\": [\n    \"--config-variable\", \n    \"OS\", \n    \"ios\", \n    \"--config-variable\", \n    \"app_path\", \n    \"src/out/Release-iphoneos/fake test 4.app\", \n    \"--config-variable\", \n    \"restart\", \n    \"false\", \n    \"--config-variable\", \n    \"shards\", \n    \"1\", \n    \"--config-variable\", \n    \"test_args\", \n    \"[]\", \n    \"--config-variable\", \n    \"xcode_parallelization\", \n    \"false\", \n    \"--config-variable\", \n    \"test_cases\", \n    \"[]\", \n    \"--config-variable\", \n    \"xctest\", \n    \"false\", \n    \"--config-variable\", \n    \"use_trusted_cert\", \n    \"false\", \n    \"--isolate\", \n    \"[START_DIR]/template.isolate\", \n    \"--isolated\", \n    \"[CLEANUP]/isolate_tmp_1/3.isolated\", \n    \"--path-variable\", \n    \"app_path\", \n    \"src/out/Release-iphoneos/fake test 4.app\", \n    \"--config-variable\", \n    \"wpr_tools_path\", \n    \"NO_PATH\", \n    \"--config-variable\", \n    \"replay_path\", \n    \"NO_PATH\", \n    \"--config-variable\", \n    \"xcode_arg_name\", \n    \"xcode-build-version\", \n    \"--config-variable\", \n    \"xcode_version\", \n    \"9abc\"\n  ], \n  \"dir\": \"[START_DIR]\", \n  \"version\": 1\n}",
       "[CLEANUP]/isolate_tmp_1/3.isolated.gen.json"
     ],
     "cwd": "[START_DIR]/src",
@@ -623,6 +629,9 @@
       "@@@STEP_LOG_LINE@3.isolated.gen.json@    \"test_args\", @@@",
       "@@@STEP_LOG_LINE@3.isolated.gen.json@    \"[]\", @@@",
       "@@@STEP_LOG_LINE@3.isolated.gen.json@    \"--config-variable\", @@@",
+      "@@@STEP_LOG_LINE@3.isolated.gen.json@    \"xcode_parallelization\", @@@",
+      "@@@STEP_LOG_LINE@3.isolated.gen.json@    \"false\", @@@",
+      "@@@STEP_LOG_LINE@3.isolated.gen.json@    \"--config-variable\", @@@",
       "@@@STEP_LOG_LINE@3.isolated.gen.json@    \"test_cases\", @@@",
       "@@@STEP_LOG_LINE@3.isolated.gen.json@    \"[]\", @@@",
       "@@@STEP_LOG_LINE@3.isolated.gen.json@    \"--config-variable\", @@@",
diff --git a/scripts/slave/recipe_modules/ios/examples/full.expected/expiration_test.json b/scripts/slave/recipe_modules/ios/examples/full.expected/expiration_test.json
index 4469a34..5eafbb4 100644
--- a/scripts/slave/recipe_modules/ios/examples/full.expected/expiration_test.json
+++ b/scripts/slave/recipe_modules/ios/examples/full.expected/expiration_test.json
@@ -366,7 +366,7 @@
       "--json-output",
       "/path/to/tmp/json",
       "copy",
-      "{'conditions': [['OS == \"ios\"', {'variables': {'files': ['<(app_path)/', 'src/ios/build/bots/scripts/', 'src/out/Debug-iphonesimulator/iossim'], 'command': ['src/ios/build/bots/scripts/run.py', '--app', '<(app_path)', '--args-json', '{\"test_args\": <(test_args),         \"xctest\": <(xctest),         \"test_cases\": <(test_cases),         \"restart\": <(restart)}', '--out-dir', '${ISOLATED_OUTDIR}', '--retries', '3', '--shards', '<(shards)', '--<(xcode_arg_name)', '<(xcode_version)', '--mac-toolchain-cmd', './mac_toolchain', '--xcode-path', 'Xcode.app', '--wpr-tools-path', '<(wpr_tools_path)', '--replay-path', '<(replay_path)', '--iossim', 'src/out/Debug-iphonesimulator/iossim', '--platform', '<(platform)', '--version', '<(version)']}}]]}",
+      "{'conditions': [['OS == \"ios\"', {'variables': {'files': ['<(app_path)/', 'src/ios/build/bots/scripts/', 'src/out/Debug-iphonesimulator/iossim'], 'command': ['src/ios/build/bots/scripts/run.py', '--app', '<(app_path)', '--args-json', '{\"test_args\": <(test_args),         \"xctest\": <(xctest),         \"test_cases\": <(test_cases),         \"restart\": <(restart),         \"xcode-parallelization\": <(xcode_parallelization)}', '--out-dir', '${ISOLATED_OUTDIR}', '--retries', '3', '--shards', '<(shards)', '--<(xcode_arg_name)', '<(xcode_version)', '--mac-toolchain-cmd', './mac_toolchain', '--xcode-path', 'Xcode.app', '--wpr-tools-path', '<(wpr_tools_path)', '--replay-path', '<(replay_path)', '--iossim', 'src/out/Debug-iphonesimulator/iossim', '--platform', '<(platform)', '--version', '<(version)']}}]]}",
       "[START_DIR]/template.isolate"
     ],
     "cwd": "[START_DIR]/src",
@@ -385,7 +385,7 @@
       "@@@STEP_LOG_LINE@template.isolate@            \"--app\", @@@",
       "@@@STEP_LOG_LINE@template.isolate@            \"<(app_path)\", @@@",
       "@@@STEP_LOG_LINE@template.isolate@            \"--args-json\", @@@",
-      "@@@STEP_LOG_LINE@template.isolate@            \"{\\\"test_args\\\": <(test_args),         \\\"xctest\\\": <(xctest),         \\\"test_cases\\\": <(test_cases),         \\\"restart\\\": <(restart)}\", @@@",
+      "@@@STEP_LOG_LINE@template.isolate@            \"{\\\"test_args\\\": <(test_args),         \\\"xctest\\\": <(xctest),         \\\"test_cases\\\": <(test_cases),         \\\"restart\\\": <(restart),         \\\"xcode-parallelization\\\": <(xcode_parallelization)}\", @@@",
       "@@@STEP_LOG_LINE@template.isolate@            \"--out-dir\", @@@",
       "@@@STEP_LOG_LINE@template.isolate@            \"${ISOLATED_OUTDIR}\", @@@",
       "@@@STEP_LOG_LINE@template.isolate@            \"--retries\", @@@",
@@ -430,7 +430,7 @@
       "--json-output",
       "/path/to/tmp/json",
       "copy",
-      "{\n  \"args\": [\n    \"--config-variable\", \n    \"OS\", \n    \"ios\", \n    \"--config-variable\", \n    \"app_path\", \n    \"src/out/Debug-iphonesimulator/fake test.app\", \n    \"--config-variable\", \n    \"restart\", \n    \"false\", \n    \"--config-variable\", \n    \"shards\", \n    \"1\", \n    \"--config-variable\", \n    \"test_args\", \n    \"[]\", \n    \"--config-variable\", \n    \"test_cases\", \n    \"[]\", \n    \"--config-variable\", \n    \"xctest\", \n    \"false\", \n    \"--config-variable\", \n    \"use_trusted_cert\", \n    \"false\", \n    \"--isolate\", \n    \"[START_DIR]/template.isolate\", \n    \"--isolated\", \n    \"[CLEANUP]/isolate_tmp_1/0.isolated\", \n    \"--path-variable\", \n    \"app_path\", \n    \"src/out/Debug-iphonesimulator/fake test.app\", \n    \"--config-variable\", \n    \"wpr_tools_path\", \n    \"NO_PATH\", \n    \"--config-variable\", \n    \"replay_path\", \n    \"NO_PATH\", \n    \"--config-variable\", \n    \"xcode_arg_name\", \n    \"xcode-build-version\", \n    \"--config-variable\", \n    \"xcode_version\", \n    \"9abc\", \n    \"--config-variable\", \n    \"platform\", \n    \"fake device\", \n    \"--config-variable\", \n    \"version\", \n    \"8.1\"\n  ], \n  \"dir\": \"[START_DIR]\", \n  \"version\": 1\n}",
+      "{\n  \"args\": [\n    \"--config-variable\", \n    \"OS\", \n    \"ios\", \n    \"--config-variable\", \n    \"app_path\", \n    \"src/out/Debug-iphonesimulator/fake test.app\", \n    \"--config-variable\", \n    \"restart\", \n    \"false\", \n    \"--config-variable\", \n    \"shards\", \n    \"1\", \n    \"--config-variable\", \n    \"test_args\", \n    \"[]\", \n    \"--config-variable\", \n    \"xcode_parallelization\", \n    \"false\", \n    \"--config-variable\", \n    \"test_cases\", \n    \"[]\", \n    \"--config-variable\", \n    \"xctest\", \n    \"false\", \n    \"--config-variable\", \n    \"use_trusted_cert\", \n    \"false\", \n    \"--isolate\", \n    \"[START_DIR]/template.isolate\", \n    \"--isolated\", \n    \"[CLEANUP]/isolate_tmp_1/0.isolated\", \n    \"--path-variable\", \n    \"app_path\", \n    \"src/out/Debug-iphonesimulator/fake test.app\", \n    \"--config-variable\", \n    \"wpr_tools_path\", \n    \"NO_PATH\", \n    \"--config-variable\", \n    \"replay_path\", \n    \"NO_PATH\", \n    \"--config-variable\", \n    \"xcode_arg_name\", \n    \"xcode-build-version\", \n    \"--config-variable\", \n    \"xcode_version\", \n    \"9abc\", \n    \"--config-variable\", \n    \"platform\", \n    \"fake device\", \n    \"--config-variable\", \n    \"version\", \n    \"8.1\"\n  ], \n  \"dir\": \"[START_DIR]\", \n  \"version\": 1\n}",
       "[CLEANUP]/isolate_tmp_1/0.isolated.gen.json"
     ],
     "cwd": "[START_DIR]/src",
@@ -457,6 +457,9 @@
       "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"test_args\", @@@",
       "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"[]\", @@@",
       "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"--config-variable\", @@@",
+      "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"xcode_parallelization\", @@@",
+      "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"false\", @@@",
+      "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"--config-variable\", @@@",
       "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"test_cases\", @@@",
       "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"[]\", @@@",
       "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"--config-variable\", @@@",
diff --git a/scripts/slave/recipe_modules/ios/examples/full.expected/expired.json b/scripts/slave/recipe_modules/ios/examples/full.expected/expired.json
index e75cddf..a227b2c 100644
--- a/scripts/slave/recipe_modules/ios/examples/full.expected/expired.json
+++ b/scripts/slave/recipe_modules/ios/examples/full.expected/expired.json
@@ -363,7 +363,7 @@
       "--json-output",
       "/path/to/tmp/json",
       "copy",
-      "{'conditions': [['OS == \"ios\"', {'variables': {'files': ['<(app_path)/', 'src/ios/build/bots/scripts/', 'src/out/Debug-iphonesimulator/iossim'], 'command': ['src/ios/build/bots/scripts/run.py', '--app', '<(app_path)', '--args-json', '{\"test_args\": <(test_args),         \"xctest\": <(xctest),         \"test_cases\": <(test_cases),         \"restart\": <(restart)}', '--out-dir', '${ISOLATED_OUTDIR}', '--retries', '3', '--shards', '<(shards)', '--<(xcode_arg_name)', '<(xcode_version)', '--mac-toolchain-cmd', './mac_toolchain', '--xcode-path', 'Xcode.app', '--wpr-tools-path', '<(wpr_tools_path)', '--replay-path', '<(replay_path)', '--iossim', 'src/out/Debug-iphonesimulator/iossim', '--platform', '<(platform)', '--version', '<(version)']}}]]}",
+      "{'conditions': [['OS == \"ios\"', {'variables': {'files': ['<(app_path)/', 'src/ios/build/bots/scripts/', 'src/out/Debug-iphonesimulator/iossim'], 'command': ['src/ios/build/bots/scripts/run.py', '--app', '<(app_path)', '--args-json', '{\"test_args\": <(test_args),         \"xctest\": <(xctest),         \"test_cases\": <(test_cases),         \"restart\": <(restart),         \"xcode-parallelization\": <(xcode_parallelization)}', '--out-dir', '${ISOLATED_OUTDIR}', '--retries', '3', '--shards', '<(shards)', '--<(xcode_arg_name)', '<(xcode_version)', '--mac-toolchain-cmd', './mac_toolchain', '--xcode-path', 'Xcode.app', '--wpr-tools-path', '<(wpr_tools_path)', '--replay-path', '<(replay_path)', '--iossim', 'src/out/Debug-iphonesimulator/iossim', '--platform', '<(platform)', '--version', '<(version)']}}]]}",
       "[START_DIR]/template.isolate"
     ],
     "cwd": "[START_DIR]/src",
@@ -382,7 +382,7 @@
       "@@@STEP_LOG_LINE@template.isolate@            \"--app\", @@@",
       "@@@STEP_LOG_LINE@template.isolate@            \"<(app_path)\", @@@",
       "@@@STEP_LOG_LINE@template.isolate@            \"--args-json\", @@@",
-      "@@@STEP_LOG_LINE@template.isolate@            \"{\\\"test_args\\\": <(test_args),         \\\"xctest\\\": <(xctest),         \\\"test_cases\\\": <(test_cases),         \\\"restart\\\": <(restart)}\", @@@",
+      "@@@STEP_LOG_LINE@template.isolate@            \"{\\\"test_args\\\": <(test_args),         \\\"xctest\\\": <(xctest),         \\\"test_cases\\\": <(test_cases),         \\\"restart\\\": <(restart),         \\\"xcode-parallelization\\\": <(xcode_parallelization)}\", @@@",
       "@@@STEP_LOG_LINE@template.isolate@            \"--out-dir\", @@@",
       "@@@STEP_LOG_LINE@template.isolate@            \"${ISOLATED_OUTDIR}\", @@@",
       "@@@STEP_LOG_LINE@template.isolate@            \"--retries\", @@@",
@@ -427,7 +427,7 @@
       "--json-output",
       "/path/to/tmp/json",
       "copy",
-      "{\n  \"args\": [\n    \"--config-variable\", \n    \"OS\", \n    \"ios\", \n    \"--config-variable\", \n    \"app_path\", \n    \"src/out/Debug-iphonesimulator/fake test.app\", \n    \"--config-variable\", \n    \"restart\", \n    \"false\", \n    \"--config-variable\", \n    \"shards\", \n    \"1\", \n    \"--config-variable\", \n    \"test_args\", \n    \"[]\", \n    \"--config-variable\", \n    \"test_cases\", \n    \"[]\", \n    \"--config-variable\", \n    \"xctest\", \n    \"false\", \n    \"--config-variable\", \n    \"use_trusted_cert\", \n    \"false\", \n    \"--isolate\", \n    \"[START_DIR]/template.isolate\", \n    \"--isolated\", \n    \"[CLEANUP]/isolate_tmp_1/0.isolated\", \n    \"--path-variable\", \n    \"app_path\", \n    \"src/out/Debug-iphonesimulator/fake test.app\", \n    \"--config-variable\", \n    \"wpr_tools_path\", \n    \"NO_PATH\", \n    \"--config-variable\", \n    \"replay_path\", \n    \"NO_PATH\", \n    \"--config-variable\", \n    \"xcode_arg_name\", \n    \"xcode-build-version\", \n    \"--config-variable\", \n    \"xcode_version\", \n    \"9abc\", \n    \"--config-variable\", \n    \"platform\", \n    \"fake device\", \n    \"--config-variable\", \n    \"version\", \n    \"8.1\"\n  ], \n  \"dir\": \"[START_DIR]\", \n  \"version\": 1\n}",
+      "{\n  \"args\": [\n    \"--config-variable\", \n    \"OS\", \n    \"ios\", \n    \"--config-variable\", \n    \"app_path\", \n    \"src/out/Debug-iphonesimulator/fake test.app\", \n    \"--config-variable\", \n    \"restart\", \n    \"false\", \n    \"--config-variable\", \n    \"shards\", \n    \"1\", \n    \"--config-variable\", \n    \"test_args\", \n    \"[]\", \n    \"--config-variable\", \n    \"xcode_parallelization\", \n    \"false\", \n    \"--config-variable\", \n    \"test_cases\", \n    \"[]\", \n    \"--config-variable\", \n    \"xctest\", \n    \"false\", \n    \"--config-variable\", \n    \"use_trusted_cert\", \n    \"false\", \n    \"--isolate\", \n    \"[START_DIR]/template.isolate\", \n    \"--isolated\", \n    \"[CLEANUP]/isolate_tmp_1/0.isolated\", \n    \"--path-variable\", \n    \"app_path\", \n    \"src/out/Debug-iphonesimulator/fake test.app\", \n    \"--config-variable\", \n    \"wpr_tools_path\", \n    \"NO_PATH\", \n    \"--config-variable\", \n    \"replay_path\", \n    \"NO_PATH\", \n    \"--config-variable\", \n    \"xcode_arg_name\", \n    \"xcode-build-version\", \n    \"--config-variable\", \n    \"xcode_version\", \n    \"9abc\", \n    \"--config-variable\", \n    \"platform\", \n    \"fake device\", \n    \"--config-variable\", \n    \"version\", \n    \"8.1\"\n  ], \n  \"dir\": \"[START_DIR]\", \n  \"version\": 1\n}",
       "[CLEANUP]/isolate_tmp_1/0.isolated.gen.json"
     ],
     "cwd": "[START_DIR]/src",
@@ -454,6 +454,9 @@
       "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"test_args\", @@@",
       "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"[]\", @@@",
       "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"--config-variable\", @@@",
+      "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"xcode_parallelization\", @@@",
+      "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"false\", @@@",
+      "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"--config-variable\", @@@",
       "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"test_cases\", @@@",
       "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"[]\", @@@",
       "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"--config-variable\", @@@",
diff --git a/scripts/slave/recipe_modules/ios/examples/full.expected/explain.json b/scripts/slave/recipe_modules/ios/examples/full.expected/explain.json
index 2fd8bca..4e5ae94 100644
--- a/scripts/slave/recipe_modules/ios/examples/full.expected/explain.json
+++ b/scripts/slave/recipe_modules/ios/examples/full.expected/explain.json
@@ -372,7 +372,7 @@
       "--json-output",
       "/path/to/tmp/json",
       "copy",
-      "{'conditions': [['OS == \"ios\"', {'variables': {'files': ['<(app_path)/', 'src/ios/build/bots/scripts/', 'src/out/Debug-iphonesimulator/iossim'], 'command': ['src/ios/build/bots/scripts/run.py', '--app', '<(app_path)', '--args-json', '{\"test_args\": <(test_args),         \"xctest\": <(xctest),         \"test_cases\": <(test_cases),         \"restart\": <(restart)}', '--out-dir', '${ISOLATED_OUTDIR}', '--retries', '3', '--shards', '<(shards)', '--<(xcode_arg_name)', '<(xcode_version)', '--mac-toolchain-cmd', './mac_toolchain', '--xcode-path', 'Xcode.app', '--wpr-tools-path', '<(wpr_tools_path)', '--replay-path', '<(replay_path)', '--iossim', 'src/out/Debug-iphonesimulator/iossim', '--platform', '<(platform)', '--version', '<(version)']}}]]}",
+      "{'conditions': [['OS == \"ios\"', {'variables': {'files': ['<(app_path)/', 'src/ios/build/bots/scripts/', 'src/out/Debug-iphonesimulator/iossim'], 'command': ['src/ios/build/bots/scripts/run.py', '--app', '<(app_path)', '--args-json', '{\"test_args\": <(test_args),         \"xctest\": <(xctest),         \"test_cases\": <(test_cases),         \"restart\": <(restart),         \"xcode-parallelization\": <(xcode_parallelization)}', '--out-dir', '${ISOLATED_OUTDIR}', '--retries', '3', '--shards', '<(shards)', '--<(xcode_arg_name)', '<(xcode_version)', '--mac-toolchain-cmd', './mac_toolchain', '--xcode-path', 'Xcode.app', '--wpr-tools-path', '<(wpr_tools_path)', '--replay-path', '<(replay_path)', '--iossim', 'src/out/Debug-iphonesimulator/iossim', '--platform', '<(platform)', '--version', '<(version)']}}]]}",
       "[START_DIR]/template.isolate"
     ],
     "cwd": "[START_DIR]/src",
@@ -391,7 +391,7 @@
       "@@@STEP_LOG_LINE@template.isolate@            \"--app\", @@@",
       "@@@STEP_LOG_LINE@template.isolate@            \"<(app_path)\", @@@",
       "@@@STEP_LOG_LINE@template.isolate@            \"--args-json\", @@@",
-      "@@@STEP_LOG_LINE@template.isolate@            \"{\\\"test_args\\\": <(test_args),         \\\"xctest\\\": <(xctest),         \\\"test_cases\\\": <(test_cases),         \\\"restart\\\": <(restart)}\", @@@",
+      "@@@STEP_LOG_LINE@template.isolate@            \"{\\\"test_args\\\": <(test_args),         \\\"xctest\\\": <(xctest),         \\\"test_cases\\\": <(test_cases),         \\\"restart\\\": <(restart),         \\\"xcode-parallelization\\\": <(xcode_parallelization)}\", @@@",
       "@@@STEP_LOG_LINE@template.isolate@            \"--out-dir\", @@@",
       "@@@STEP_LOG_LINE@template.isolate@            \"${ISOLATED_OUTDIR}\", @@@",
       "@@@STEP_LOG_LINE@template.isolate@            \"--retries\", @@@",
diff --git a/scripts/slave/recipe_modules/ios/examples/full.expected/fyi.json b/scripts/slave/recipe_modules/ios/examples/full.expected/fyi.json
index b3af74b..44d3c68 100644
--- a/scripts/slave/recipe_modules/ios/examples/full.expected/fyi.json
+++ b/scripts/slave/recipe_modules/ios/examples/full.expected/fyi.json
@@ -364,7 +364,7 @@
       "--json-output",
       "/path/to/tmp/json",
       "copy",
-      "{'conditions': [['OS == \"ios\"', {'variables': {'files': ['<(app_path)/', 'src/ios/build/bots/scripts/', 'src/out/Debug-iphonesimulator/iossim'], 'command': ['src/ios/build/bots/scripts/run.py', '--app', '<(app_path)', '--args-json', '{\"test_args\": <(test_args),         \"xctest\": <(xctest),         \"test_cases\": <(test_cases),         \"restart\": <(restart)}', '--out-dir', '${ISOLATED_OUTDIR}', '--retries', '3', '--shards', '<(shards)', '--<(xcode_arg_name)', '<(xcode_version)', '--mac-toolchain-cmd', './mac_toolchain', '--xcode-path', 'Xcode.app', '--wpr-tools-path', '<(wpr_tools_path)', '--replay-path', '<(replay_path)', '--iossim', 'src/out/Debug-iphonesimulator/iossim', '--platform', '<(platform)', '--version', '<(version)']}}]]}",
+      "{'conditions': [['OS == \"ios\"', {'variables': {'files': ['<(app_path)/', 'src/ios/build/bots/scripts/', 'src/out/Debug-iphonesimulator/iossim'], 'command': ['src/ios/build/bots/scripts/run.py', '--app', '<(app_path)', '--args-json', '{\"test_args\": <(test_args),         \"xctest\": <(xctest),         \"test_cases\": <(test_cases),         \"restart\": <(restart),         \"xcode-parallelization\": <(xcode_parallelization)}', '--out-dir', '${ISOLATED_OUTDIR}', '--retries', '3', '--shards', '<(shards)', '--<(xcode_arg_name)', '<(xcode_version)', '--mac-toolchain-cmd', './mac_toolchain', '--xcode-path', 'Xcode.app', '--wpr-tools-path', '<(wpr_tools_path)', '--replay-path', '<(replay_path)', '--iossim', 'src/out/Debug-iphonesimulator/iossim', '--platform', '<(platform)', '--version', '<(version)']}}]]}",
       "[START_DIR]/template.isolate"
     ],
     "cwd": "[START_DIR]/src",
@@ -383,7 +383,7 @@
       "@@@STEP_LOG_LINE@template.isolate@            \"--app\", @@@",
       "@@@STEP_LOG_LINE@template.isolate@            \"<(app_path)\", @@@",
       "@@@STEP_LOG_LINE@template.isolate@            \"--args-json\", @@@",
-      "@@@STEP_LOG_LINE@template.isolate@            \"{\\\"test_args\\\": <(test_args),         \\\"xctest\\\": <(xctest),         \\\"test_cases\\\": <(test_cases),         \\\"restart\\\": <(restart)}\", @@@",
+      "@@@STEP_LOG_LINE@template.isolate@            \"{\\\"test_args\\\": <(test_args),         \\\"xctest\\\": <(xctest),         \\\"test_cases\\\": <(test_cases),         \\\"restart\\\": <(restart),         \\\"xcode-parallelization\\\": <(xcode_parallelization)}\", @@@",
       "@@@STEP_LOG_LINE@template.isolate@            \"--out-dir\", @@@",
       "@@@STEP_LOG_LINE@template.isolate@            \"${ISOLATED_OUTDIR}\", @@@",
       "@@@STEP_LOG_LINE@template.isolate@            \"--retries\", @@@",
@@ -428,7 +428,7 @@
       "--json-output",
       "/path/to/tmp/json",
       "copy",
-      "{\n  \"args\": [\n    \"--config-variable\", \n    \"OS\", \n    \"ios\", \n    \"--config-variable\", \n    \"app_path\", \n    \"src/out/Debug-iphonesimulator/fake test.app\", \n    \"--config-variable\", \n    \"restart\", \n    \"false\", \n    \"--config-variable\", \n    \"shards\", \n    \"1\", \n    \"--config-variable\", \n    \"test_args\", \n    \"[]\", \n    \"--config-variable\", \n    \"test_cases\", \n    \"[]\", \n    \"--config-variable\", \n    \"xctest\", \n    \"false\", \n    \"--config-variable\", \n    \"use_trusted_cert\", \n    \"false\", \n    \"--isolate\", \n    \"[START_DIR]/template.isolate\", \n    \"--isolated\", \n    \"[CLEANUP]/isolate_tmp_1/0.isolated\", \n    \"--path-variable\", \n    \"app_path\", \n    \"src/out/Debug-iphonesimulator/fake test.app\", \n    \"--config-variable\", \n    \"wpr_tools_path\", \n    \"NO_PATH\", \n    \"--config-variable\", \n    \"replay_path\", \n    \"NO_PATH\", \n    \"--config-variable\", \n    \"xcode_arg_name\", \n    \"xcode-build-version\", \n    \"--config-variable\", \n    \"xcode_version\", \n    \"9abc\", \n    \"--config-variable\", \n    \"platform\", \n    \"fake device\", \n    \"--config-variable\", \n    \"version\", \n    \"8.1\"\n  ], \n  \"dir\": \"[START_DIR]\", \n  \"version\": 1\n}",
+      "{\n  \"args\": [\n    \"--config-variable\", \n    \"OS\", \n    \"ios\", \n    \"--config-variable\", \n    \"app_path\", \n    \"src/out/Debug-iphonesimulator/fake test.app\", \n    \"--config-variable\", \n    \"restart\", \n    \"false\", \n    \"--config-variable\", \n    \"shards\", \n    \"1\", \n    \"--config-variable\", \n    \"test_args\", \n    \"[]\", \n    \"--config-variable\", \n    \"xcode_parallelization\", \n    \"false\", \n    \"--config-variable\", \n    \"test_cases\", \n    \"[]\", \n    \"--config-variable\", \n    \"xctest\", \n    \"false\", \n    \"--config-variable\", \n    \"use_trusted_cert\", \n    \"false\", \n    \"--isolate\", \n    \"[START_DIR]/template.isolate\", \n    \"--isolated\", \n    \"[CLEANUP]/isolate_tmp_1/0.isolated\", \n    \"--path-variable\", \n    \"app_path\", \n    \"src/out/Debug-iphonesimulator/fake test.app\", \n    \"--config-variable\", \n    \"wpr_tools_path\", \n    \"NO_PATH\", \n    \"--config-variable\", \n    \"replay_path\", \n    \"NO_PATH\", \n    \"--config-variable\", \n    \"xcode_arg_name\", \n    \"xcode-build-version\", \n    \"--config-variable\", \n    \"xcode_version\", \n    \"9abc\", \n    \"--config-variable\", \n    \"platform\", \n    \"fake device\", \n    \"--config-variable\", \n    \"version\", \n    \"8.1\"\n  ], \n  \"dir\": \"[START_DIR]\", \n  \"version\": 1\n}",
       "[CLEANUP]/isolate_tmp_1/0.isolated.gen.json"
     ],
     "cwd": "[START_DIR]/src",
@@ -455,6 +455,9 @@
       "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"test_args\", @@@",
       "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"[]\", @@@",
       "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"--config-variable\", @@@",
+      "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"xcode_parallelization\", @@@",
+      "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"false\", @@@",
+      "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"--config-variable\", @@@",
       "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"test_cases\", @@@",
       "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"[]\", @@@",
       "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"--config-variable\", @@@",
diff --git a/scripts/slave/recipe_modules/ios/examples/full.expected/infra_failure.json b/scripts/slave/recipe_modules/ios/examples/full.expected/infra_failure.json
index ec7ae3f..b1d0755 100644
--- a/scripts/slave/recipe_modules/ios/examples/full.expected/infra_failure.json
+++ b/scripts/slave/recipe_modules/ios/examples/full.expected/infra_failure.json
@@ -363,7 +363,7 @@
       "--json-output",
       "/path/to/tmp/json",
       "copy",
-      "{'conditions': [['OS == \"ios\"', {'variables': {'files': ['<(app_path)/', 'src/ios/build/bots/scripts/', 'src/out/Debug-iphonesimulator/iossim'], 'command': ['src/ios/build/bots/scripts/run.py', '--app', '<(app_path)', '--args-json', '{\"test_args\": <(test_args),         \"xctest\": <(xctest),         \"test_cases\": <(test_cases),         \"restart\": <(restart)}', '--out-dir', '${ISOLATED_OUTDIR}', '--retries', '3', '--shards', '<(shards)', '--<(xcode_arg_name)', '<(xcode_version)', '--mac-toolchain-cmd', './mac_toolchain', '--xcode-path', 'Xcode.app', '--wpr-tools-path', '<(wpr_tools_path)', '--replay-path', '<(replay_path)', '--iossim', 'src/out/Debug-iphonesimulator/iossim', '--platform', '<(platform)', '--version', '<(version)']}}]]}",
+      "{'conditions': [['OS == \"ios\"', {'variables': {'files': ['<(app_path)/', 'src/ios/build/bots/scripts/', 'src/out/Debug-iphonesimulator/iossim'], 'command': ['src/ios/build/bots/scripts/run.py', '--app', '<(app_path)', '--args-json', '{\"test_args\": <(test_args),         \"xctest\": <(xctest),         \"test_cases\": <(test_cases),         \"restart\": <(restart),         \"xcode-parallelization\": <(xcode_parallelization)}', '--out-dir', '${ISOLATED_OUTDIR}', '--retries', '3', '--shards', '<(shards)', '--<(xcode_arg_name)', '<(xcode_version)', '--mac-toolchain-cmd', './mac_toolchain', '--xcode-path', 'Xcode.app', '--wpr-tools-path', '<(wpr_tools_path)', '--replay-path', '<(replay_path)', '--iossim', 'src/out/Debug-iphonesimulator/iossim', '--platform', '<(platform)', '--version', '<(version)']}}]]}",
       "[START_DIR]/template.isolate"
     ],
     "cwd": "[START_DIR]/src",
@@ -382,7 +382,7 @@
       "@@@STEP_LOG_LINE@template.isolate@            \"--app\", @@@",
       "@@@STEP_LOG_LINE@template.isolate@            \"<(app_path)\", @@@",
       "@@@STEP_LOG_LINE@template.isolate@            \"--args-json\", @@@",
-      "@@@STEP_LOG_LINE@template.isolate@            \"{\\\"test_args\\\": <(test_args),         \\\"xctest\\\": <(xctest),         \\\"test_cases\\\": <(test_cases),         \\\"restart\\\": <(restart)}\", @@@",
+      "@@@STEP_LOG_LINE@template.isolate@            \"{\\\"test_args\\\": <(test_args),         \\\"xctest\\\": <(xctest),         \\\"test_cases\\\": <(test_cases),         \\\"restart\\\": <(restart),         \\\"xcode-parallelization\\\": <(xcode_parallelization)}\", @@@",
       "@@@STEP_LOG_LINE@template.isolate@            \"--out-dir\", @@@",
       "@@@STEP_LOG_LINE@template.isolate@            \"${ISOLATED_OUTDIR}\", @@@",
       "@@@STEP_LOG_LINE@template.isolate@            \"--retries\", @@@",
@@ -427,7 +427,7 @@
       "--json-output",
       "/path/to/tmp/json",
       "copy",
-      "{\n  \"args\": [\n    \"--config-variable\", \n    \"OS\", \n    \"ios\", \n    \"--config-variable\", \n    \"app_path\", \n    \"src/out/Debug-iphonesimulator/fake test.app\", \n    \"--config-variable\", \n    \"restart\", \n    \"false\", \n    \"--config-variable\", \n    \"shards\", \n    \"1\", \n    \"--config-variable\", \n    \"test_args\", \n    \"[]\", \n    \"--config-variable\", \n    \"test_cases\", \n    \"[]\", \n    \"--config-variable\", \n    \"xctest\", \n    \"false\", \n    \"--config-variable\", \n    \"use_trusted_cert\", \n    \"false\", \n    \"--isolate\", \n    \"[START_DIR]/template.isolate\", \n    \"--isolated\", \n    \"[CLEANUP]/isolate_tmp_1/0.isolated\", \n    \"--path-variable\", \n    \"app_path\", \n    \"src/out/Debug-iphonesimulator/fake test.app\", \n    \"--config-variable\", \n    \"wpr_tools_path\", \n    \"NO_PATH\", \n    \"--config-variable\", \n    \"replay_path\", \n    \"NO_PATH\", \n    \"--config-variable\", \n    \"xcode_arg_name\", \n    \"xcode-build-version\", \n    \"--config-variable\", \n    \"xcode_version\", \n    \"9abc\", \n    \"--config-variable\", \n    \"platform\", \n    \"fake device\", \n    \"--config-variable\", \n    \"version\", \n    \"8.1\"\n  ], \n  \"dir\": \"[START_DIR]\", \n  \"version\": 1\n}",
+      "{\n  \"args\": [\n    \"--config-variable\", \n    \"OS\", \n    \"ios\", \n    \"--config-variable\", \n    \"app_path\", \n    \"src/out/Debug-iphonesimulator/fake test.app\", \n    \"--config-variable\", \n    \"restart\", \n    \"false\", \n    \"--config-variable\", \n    \"shards\", \n    \"1\", \n    \"--config-variable\", \n    \"test_args\", \n    \"[]\", \n    \"--config-variable\", \n    \"xcode_parallelization\", \n    \"false\", \n    \"--config-variable\", \n    \"test_cases\", \n    \"[]\", \n    \"--config-variable\", \n    \"xctest\", \n    \"false\", \n    \"--config-variable\", \n    \"use_trusted_cert\", \n    \"false\", \n    \"--isolate\", \n    \"[START_DIR]/template.isolate\", \n    \"--isolated\", \n    \"[CLEANUP]/isolate_tmp_1/0.isolated\", \n    \"--path-variable\", \n    \"app_path\", \n    \"src/out/Debug-iphonesimulator/fake test.app\", \n    \"--config-variable\", \n    \"wpr_tools_path\", \n    \"NO_PATH\", \n    \"--config-variable\", \n    \"replay_path\", \n    \"NO_PATH\", \n    \"--config-variable\", \n    \"xcode_arg_name\", \n    \"xcode-build-version\", \n    \"--config-variable\", \n    \"xcode_version\", \n    \"9abc\", \n    \"--config-variable\", \n    \"platform\", \n    \"fake device\", \n    \"--config-variable\", \n    \"version\", \n    \"8.1\"\n  ], \n  \"dir\": \"[START_DIR]\", \n  \"version\": 1\n}",
       "[CLEANUP]/isolate_tmp_1/0.isolated.gen.json"
     ],
     "cwd": "[START_DIR]/src",
@@ -454,6 +454,9 @@
       "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"test_args\", @@@",
       "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"[]\", @@@",
       "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"--config-variable\", @@@",
+      "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"xcode_parallelization\", @@@",
+      "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"false\", @@@",
+      "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"--config-variable\", @@@",
       "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"test_cases\", @@@",
       "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"[]\", @@@",
       "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"--config-variable\", @@@",
diff --git a/scripts/slave/recipe_modules/ios/examples/full.expected/max_runtime_test.json b/scripts/slave/recipe_modules/ios/examples/full.expected/max_runtime_test.json
index bbece4d..82b1cfe 100644
--- a/scripts/slave/recipe_modules/ios/examples/full.expected/max_runtime_test.json
+++ b/scripts/slave/recipe_modules/ios/examples/full.expected/max_runtime_test.json
@@ -366,7 +366,7 @@
       "--json-output",
       "/path/to/tmp/json",
       "copy",
-      "{'conditions': [['OS == \"ios\"', {'variables': {'files': ['<(app_path)/', 'src/ios/build/bots/scripts/', 'src/out/Debug-iphonesimulator/iossim'], 'command': ['src/ios/build/bots/scripts/run.py', '--app', '<(app_path)', '--args-json', '{\"test_args\": <(test_args),         \"xctest\": <(xctest),         \"test_cases\": <(test_cases),         \"restart\": <(restart)}', '--out-dir', '${ISOLATED_OUTDIR}', '--retries', '3', '--shards', '<(shards)', '--<(xcode_arg_name)', '<(xcode_version)', '--mac-toolchain-cmd', './mac_toolchain', '--xcode-path', 'Xcode.app', '--wpr-tools-path', '<(wpr_tools_path)', '--replay-path', '<(replay_path)', '--iossim', 'src/out/Debug-iphonesimulator/iossim', '--platform', '<(platform)', '--version', '<(version)']}}]]}",
+      "{'conditions': [['OS == \"ios\"', {'variables': {'files': ['<(app_path)/', 'src/ios/build/bots/scripts/', 'src/out/Debug-iphonesimulator/iossim'], 'command': ['src/ios/build/bots/scripts/run.py', '--app', '<(app_path)', '--args-json', '{\"test_args\": <(test_args),         \"xctest\": <(xctest),         \"test_cases\": <(test_cases),         \"restart\": <(restart),         \"xcode-parallelization\": <(xcode_parallelization)}', '--out-dir', '${ISOLATED_OUTDIR}', '--retries', '3', '--shards', '<(shards)', '--<(xcode_arg_name)', '<(xcode_version)', '--mac-toolchain-cmd', './mac_toolchain', '--xcode-path', 'Xcode.app', '--wpr-tools-path', '<(wpr_tools_path)', '--replay-path', '<(replay_path)', '--iossim', 'src/out/Debug-iphonesimulator/iossim', '--platform', '<(platform)', '--version', '<(version)']}}]]}",
       "[START_DIR]/template.isolate"
     ],
     "cwd": "[START_DIR]/src",
@@ -385,7 +385,7 @@
       "@@@STEP_LOG_LINE@template.isolate@            \"--app\", @@@",
       "@@@STEP_LOG_LINE@template.isolate@            \"<(app_path)\", @@@",
       "@@@STEP_LOG_LINE@template.isolate@            \"--args-json\", @@@",
-      "@@@STEP_LOG_LINE@template.isolate@            \"{\\\"test_args\\\": <(test_args),         \\\"xctest\\\": <(xctest),         \\\"test_cases\\\": <(test_cases),         \\\"restart\\\": <(restart)}\", @@@",
+      "@@@STEP_LOG_LINE@template.isolate@            \"{\\\"test_args\\\": <(test_args),         \\\"xctest\\\": <(xctest),         \\\"test_cases\\\": <(test_cases),         \\\"restart\\\": <(restart),         \\\"xcode-parallelization\\\": <(xcode_parallelization)}\", @@@",
       "@@@STEP_LOG_LINE@template.isolate@            \"--out-dir\", @@@",
       "@@@STEP_LOG_LINE@template.isolate@            \"${ISOLATED_OUTDIR}\", @@@",
       "@@@STEP_LOG_LINE@template.isolate@            \"--retries\", @@@",
@@ -430,7 +430,7 @@
       "--json-output",
       "/path/to/tmp/json",
       "copy",
-      "{\n  \"args\": [\n    \"--config-variable\", \n    \"OS\", \n    \"ios\", \n    \"--config-variable\", \n    \"app_path\", \n    \"src/out/Debug-iphonesimulator/fake test.app\", \n    \"--config-variable\", \n    \"restart\", \n    \"false\", \n    \"--config-variable\", \n    \"shards\", \n    \"1\", \n    \"--config-variable\", \n    \"test_args\", \n    \"[]\", \n    \"--config-variable\", \n    \"test_cases\", \n    \"[]\", \n    \"--config-variable\", \n    \"xctest\", \n    \"false\", \n    \"--config-variable\", \n    \"use_trusted_cert\", \n    \"false\", \n    \"--isolate\", \n    \"[START_DIR]/template.isolate\", \n    \"--isolated\", \n    \"[CLEANUP]/isolate_tmp_1/0.isolated\", \n    \"--path-variable\", \n    \"app_path\", \n    \"src/out/Debug-iphonesimulator/fake test.app\", \n    \"--config-variable\", \n    \"wpr_tools_path\", \n    \"NO_PATH\", \n    \"--config-variable\", \n    \"replay_path\", \n    \"NO_PATH\", \n    \"--config-variable\", \n    \"xcode_arg_name\", \n    \"xcode-build-version\", \n    \"--config-variable\", \n    \"xcode_version\", \n    \"9abc\", \n    \"--config-variable\", \n    \"platform\", \n    \"fake device\", \n    \"--config-variable\", \n    \"version\", \n    \"8.1\"\n  ], \n  \"dir\": \"[START_DIR]\", \n  \"version\": 1\n}",
+      "{\n  \"args\": [\n    \"--config-variable\", \n    \"OS\", \n    \"ios\", \n    \"--config-variable\", \n    \"app_path\", \n    \"src/out/Debug-iphonesimulator/fake test.app\", \n    \"--config-variable\", \n    \"restart\", \n    \"false\", \n    \"--config-variable\", \n    \"shards\", \n    \"1\", \n    \"--config-variable\", \n    \"test_args\", \n    \"[]\", \n    \"--config-variable\", \n    \"xcode_parallelization\", \n    \"false\", \n    \"--config-variable\", \n    \"test_cases\", \n    \"[]\", \n    \"--config-variable\", \n    \"xctest\", \n    \"false\", \n    \"--config-variable\", \n    \"use_trusted_cert\", \n    \"false\", \n    \"--isolate\", \n    \"[START_DIR]/template.isolate\", \n    \"--isolated\", \n    \"[CLEANUP]/isolate_tmp_1/0.isolated\", \n    \"--path-variable\", \n    \"app_path\", \n    \"src/out/Debug-iphonesimulator/fake test.app\", \n    \"--config-variable\", \n    \"wpr_tools_path\", \n    \"NO_PATH\", \n    \"--config-variable\", \n    \"replay_path\", \n    \"NO_PATH\", \n    \"--config-variable\", \n    \"xcode_arg_name\", \n    \"xcode-build-version\", \n    \"--config-variable\", \n    \"xcode_version\", \n    \"9abc\", \n    \"--config-variable\", \n    \"platform\", \n    \"fake device\", \n    \"--config-variable\", \n    \"version\", \n    \"8.1\"\n  ], \n  \"dir\": \"[START_DIR]\", \n  \"version\": 1\n}",
       "[CLEANUP]/isolate_tmp_1/0.isolated.gen.json"
     ],
     "cwd": "[START_DIR]/src",
@@ -457,6 +457,9 @@
       "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"test_args\", @@@",
       "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"[]\", @@@",
       "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"--config-variable\", @@@",
+      "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"xcode_parallelization\", @@@",
+      "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"false\", @@@",
+      "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"--config-variable\", @@@",
       "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"test_cases\", @@@",
       "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"[]\", @@@",
       "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"--config-variable\", @@@",
diff --git a/scripts/slave/recipe_modules/ios/examples/full.expected/no_exit_code.json b/scripts/slave/recipe_modules/ios/examples/full.expected/no_exit_code.json
index 84560e5..e39d37d 100644
--- a/scripts/slave/recipe_modules/ios/examples/full.expected/no_exit_code.json
+++ b/scripts/slave/recipe_modules/ios/examples/full.expected/no_exit_code.json
@@ -363,7 +363,7 @@
       "--json-output",
       "/path/to/tmp/json",
       "copy",
-      "{'conditions': [['OS == \"ios\"', {'variables': {'files': ['<(app_path)/', 'src/ios/build/bots/scripts/', 'src/out/Debug-iphonesimulator/iossim'], 'command': ['src/ios/build/bots/scripts/run.py', '--app', '<(app_path)', '--args-json', '{\"test_args\": <(test_args),         \"xctest\": <(xctest),         \"test_cases\": <(test_cases),         \"restart\": <(restart)}', '--out-dir', '${ISOLATED_OUTDIR}', '--retries', '3', '--shards', '<(shards)', '--<(xcode_arg_name)', '<(xcode_version)', '--mac-toolchain-cmd', './mac_toolchain', '--xcode-path', 'Xcode.app', '--wpr-tools-path', '<(wpr_tools_path)', '--replay-path', '<(replay_path)', '--iossim', 'src/out/Debug-iphonesimulator/iossim', '--platform', '<(platform)', '--version', '<(version)']}}]]}",
+      "{'conditions': [['OS == \"ios\"', {'variables': {'files': ['<(app_path)/', 'src/ios/build/bots/scripts/', 'src/out/Debug-iphonesimulator/iossim'], 'command': ['src/ios/build/bots/scripts/run.py', '--app', '<(app_path)', '--args-json', '{\"test_args\": <(test_args),         \"xctest\": <(xctest),         \"test_cases\": <(test_cases),         \"restart\": <(restart),         \"xcode-parallelization\": <(xcode_parallelization)}', '--out-dir', '${ISOLATED_OUTDIR}', '--retries', '3', '--shards', '<(shards)', '--<(xcode_arg_name)', '<(xcode_version)', '--mac-toolchain-cmd', './mac_toolchain', '--xcode-path', 'Xcode.app', '--wpr-tools-path', '<(wpr_tools_path)', '--replay-path', '<(replay_path)', '--iossim', 'src/out/Debug-iphonesimulator/iossim', '--platform', '<(platform)', '--version', '<(version)']}}]]}",
       "[START_DIR]/template.isolate"
     ],
     "cwd": "[START_DIR]/src",
@@ -382,7 +382,7 @@
       "@@@STEP_LOG_LINE@template.isolate@            \"--app\", @@@",
       "@@@STEP_LOG_LINE@template.isolate@            \"<(app_path)\", @@@",
       "@@@STEP_LOG_LINE@template.isolate@            \"--args-json\", @@@",
-      "@@@STEP_LOG_LINE@template.isolate@            \"{\\\"test_args\\\": <(test_args),         \\\"xctest\\\": <(xctest),         \\\"test_cases\\\": <(test_cases),         \\\"restart\\\": <(restart)}\", @@@",
+      "@@@STEP_LOG_LINE@template.isolate@            \"{\\\"test_args\\\": <(test_args),         \\\"xctest\\\": <(xctest),         \\\"test_cases\\\": <(test_cases),         \\\"restart\\\": <(restart),         \\\"xcode-parallelization\\\": <(xcode_parallelization)}\", @@@",
       "@@@STEP_LOG_LINE@template.isolate@            \"--out-dir\", @@@",
       "@@@STEP_LOG_LINE@template.isolate@            \"${ISOLATED_OUTDIR}\", @@@",
       "@@@STEP_LOG_LINE@template.isolate@            \"--retries\", @@@",
@@ -427,7 +427,7 @@
       "--json-output",
       "/path/to/tmp/json",
       "copy",
-      "{\n  \"args\": [\n    \"--config-variable\", \n    \"OS\", \n    \"ios\", \n    \"--config-variable\", \n    \"app_path\", \n    \"src/out/Debug-iphonesimulator/fake test.app\", \n    \"--config-variable\", \n    \"restart\", \n    \"false\", \n    \"--config-variable\", \n    \"shards\", \n    \"1\", \n    \"--config-variable\", \n    \"test_args\", \n    \"[]\", \n    \"--config-variable\", \n    \"test_cases\", \n    \"[]\", \n    \"--config-variable\", \n    \"xctest\", \n    \"false\", \n    \"--config-variable\", \n    \"use_trusted_cert\", \n    \"false\", \n    \"--isolate\", \n    \"[START_DIR]/template.isolate\", \n    \"--isolated\", \n    \"[CLEANUP]/isolate_tmp_1/0.isolated\", \n    \"--path-variable\", \n    \"app_path\", \n    \"src/out/Debug-iphonesimulator/fake test.app\", \n    \"--config-variable\", \n    \"wpr_tools_path\", \n    \"NO_PATH\", \n    \"--config-variable\", \n    \"replay_path\", \n    \"NO_PATH\", \n    \"--config-variable\", \n    \"xcode_arg_name\", \n    \"xcode-build-version\", \n    \"--config-variable\", \n    \"xcode_version\", \n    \"9abc\", \n    \"--config-variable\", \n    \"platform\", \n    \"fake device\", \n    \"--config-variable\", \n    \"version\", \n    \"8.1\"\n  ], \n  \"dir\": \"[START_DIR]\", \n  \"version\": 1\n}",
+      "{\n  \"args\": [\n    \"--config-variable\", \n    \"OS\", \n    \"ios\", \n    \"--config-variable\", \n    \"app_path\", \n    \"src/out/Debug-iphonesimulator/fake test.app\", \n    \"--config-variable\", \n    \"restart\", \n    \"false\", \n    \"--config-variable\", \n    \"shards\", \n    \"1\", \n    \"--config-variable\", \n    \"test_args\", \n    \"[]\", \n    \"--config-variable\", \n    \"xcode_parallelization\", \n    \"false\", \n    \"--config-variable\", \n    \"test_cases\", \n    \"[]\", \n    \"--config-variable\", \n    \"xctest\", \n    \"false\", \n    \"--config-variable\", \n    \"use_trusted_cert\", \n    \"false\", \n    \"--isolate\", \n    \"[START_DIR]/template.isolate\", \n    \"--isolated\", \n    \"[CLEANUP]/isolate_tmp_1/0.isolated\", \n    \"--path-variable\", \n    \"app_path\", \n    \"src/out/Debug-iphonesimulator/fake test.app\", \n    \"--config-variable\", \n    \"wpr_tools_path\", \n    \"NO_PATH\", \n    \"--config-variable\", \n    \"replay_path\", \n    \"NO_PATH\", \n    \"--config-variable\", \n    \"xcode_arg_name\", \n    \"xcode-build-version\", \n    \"--config-variable\", \n    \"xcode_version\", \n    \"9abc\", \n    \"--config-variable\", \n    \"platform\", \n    \"fake device\", \n    \"--config-variable\", \n    \"version\", \n    \"8.1\"\n  ], \n  \"dir\": \"[START_DIR]\", \n  \"version\": 1\n}",
       "[CLEANUP]/isolate_tmp_1/0.isolated.gen.json"
     ],
     "cwd": "[START_DIR]/src",
@@ -454,6 +454,9 @@
       "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"test_args\", @@@",
       "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"[]\", @@@",
       "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"--config-variable\", @@@",
+      "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"xcode_parallelization\", @@@",
+      "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"false\", @@@",
+      "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"--config-variable\", @@@",
       "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"test_cases\", @@@",
       "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"[]\", @@@",
       "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"--config-variable\", @@@",
diff --git a/scripts/slave/recipe_modules/ios/examples/full.expected/perf_test.json b/scripts/slave/recipe_modules/ios/examples/full.expected/perf_test.json
index 5f3681a..5fdc0d0 100644
--- a/scripts/slave/recipe_modules/ios/examples/full.expected/perf_test.json
+++ b/scripts/slave/recipe_modules/ios/examples/full.expected/perf_test.json
@@ -365,7 +365,7 @@
       "--json-output",
       "/path/to/tmp/json",
       "copy",
-      "{'conditions': [['OS == \"ios\"', {'variables': {'files': ['<(app_path)/', 'src/ios/build/bots/scripts/', 'src/out/Debug-iphonesimulator/iossim'], 'command': ['src/ios/build/bots/scripts/run.py', '--app', '<(app_path)', '--args-json', '{\"test_args\": <(test_args),         \"xctest\": <(xctest),         \"test_cases\": <(test_cases),         \"restart\": <(restart)}', '--out-dir', '${ISOLATED_OUTDIR}', '--retries', '3', '--shards', '<(shards)', '--<(xcode_arg_name)', '<(xcode_version)', '--mac-toolchain-cmd', './mac_toolchain', '--xcode-path', 'Xcode.app', '--wpr-tools-path', '<(wpr_tools_path)', '--replay-path', '<(replay_path)', '--iossim', 'src/out/Debug-iphonesimulator/iossim', '--platform', '<(platform)', '--version', '<(version)']}}]]}",
+      "{'conditions': [['OS == \"ios\"', {'variables': {'files': ['<(app_path)/', 'src/ios/build/bots/scripts/', 'src/out/Debug-iphonesimulator/iossim'], 'command': ['src/ios/build/bots/scripts/run.py', '--app', '<(app_path)', '--args-json', '{\"test_args\": <(test_args),         \"xctest\": <(xctest),         \"test_cases\": <(test_cases),         \"restart\": <(restart),         \"xcode-parallelization\": <(xcode_parallelization)}', '--out-dir', '${ISOLATED_OUTDIR}', '--retries', '3', '--shards', '<(shards)', '--<(xcode_arg_name)', '<(xcode_version)', '--mac-toolchain-cmd', './mac_toolchain', '--xcode-path', 'Xcode.app', '--wpr-tools-path', '<(wpr_tools_path)', '--replay-path', '<(replay_path)', '--iossim', 'src/out/Debug-iphonesimulator/iossim', '--platform', '<(platform)', '--version', '<(version)']}}]]}",
       "[START_DIR]/template.isolate"
     ],
     "cwd": "[START_DIR]/src",
@@ -384,7 +384,7 @@
       "@@@STEP_LOG_LINE@template.isolate@            \"--app\", @@@",
       "@@@STEP_LOG_LINE@template.isolate@            \"<(app_path)\", @@@",
       "@@@STEP_LOG_LINE@template.isolate@            \"--args-json\", @@@",
-      "@@@STEP_LOG_LINE@template.isolate@            \"{\\\"test_args\\\": <(test_args),         \\\"xctest\\\": <(xctest),         \\\"test_cases\\\": <(test_cases),         \\\"restart\\\": <(restart)}\", @@@",
+      "@@@STEP_LOG_LINE@template.isolate@            \"{\\\"test_args\\\": <(test_args),         \\\"xctest\\\": <(xctest),         \\\"test_cases\\\": <(test_cases),         \\\"restart\\\": <(restart),         \\\"xcode-parallelization\\\": <(xcode_parallelization)}\", @@@",
       "@@@STEP_LOG_LINE@template.isolate@            \"--out-dir\", @@@",
       "@@@STEP_LOG_LINE@template.isolate@            \"${ISOLATED_OUTDIR}\", @@@",
       "@@@STEP_LOG_LINE@template.isolate@            \"--retries\", @@@",
@@ -429,7 +429,7 @@
       "--json-output",
       "/path/to/tmp/json",
       "copy",
-      "{\n  \"args\": [\n    \"--config-variable\", \n    \"OS\", \n    \"ios\", \n    \"--config-variable\", \n    \"app_path\", \n    \"src/out/Debug-iphonesimulator/fake test.app\", \n    \"--config-variable\", \n    \"restart\", \n    \"false\", \n    \"--config-variable\", \n    \"shards\", \n    \"1\", \n    \"--config-variable\", \n    \"test_args\", \n    \"[]\", \n    \"--config-variable\", \n    \"test_cases\", \n    \"[]\", \n    \"--config-variable\", \n    \"xctest\", \n    \"false\", \n    \"--config-variable\", \n    \"use_trusted_cert\", \n    \"false\", \n    \"--isolate\", \n    \"[START_DIR]/template.isolate\", \n    \"--isolated\", \n    \"[CLEANUP]/isolate_tmp_1/0.isolated\", \n    \"--path-variable\", \n    \"app_path\", \n    \"src/out/Debug-iphonesimulator/fake test.app\", \n    \"--config-variable\", \n    \"wpr_tools_path\", \n    \"NO_PATH\", \n    \"--config-variable\", \n    \"replay_path\", \n    \"NO_PATH\", \n    \"--config-variable\", \n    \"xcode_arg_name\", \n    \"xcode-build-version\", \n    \"--config-variable\", \n    \"xcode_version\", \n    \"9abc\", \n    \"--config-variable\", \n    \"platform\", \n    \"fake device\", \n    \"--config-variable\", \n    \"version\", \n    \"8.1\"\n  ], \n  \"dir\": \"[START_DIR]\", \n  \"version\": 1\n}",
+      "{\n  \"args\": [\n    \"--config-variable\", \n    \"OS\", \n    \"ios\", \n    \"--config-variable\", \n    \"app_path\", \n    \"src/out/Debug-iphonesimulator/fake test.app\", \n    \"--config-variable\", \n    \"restart\", \n    \"false\", \n    \"--config-variable\", \n    \"shards\", \n    \"1\", \n    \"--config-variable\", \n    \"test_args\", \n    \"[]\", \n    \"--config-variable\", \n    \"xcode_parallelization\", \n    \"false\", \n    \"--config-variable\", \n    \"test_cases\", \n    \"[]\", \n    \"--config-variable\", \n    \"xctest\", \n    \"false\", \n    \"--config-variable\", \n    \"use_trusted_cert\", \n    \"false\", \n    \"--isolate\", \n    \"[START_DIR]/template.isolate\", \n    \"--isolated\", \n    \"[CLEANUP]/isolate_tmp_1/0.isolated\", \n    \"--path-variable\", \n    \"app_path\", \n    \"src/out/Debug-iphonesimulator/fake test.app\", \n    \"--config-variable\", \n    \"wpr_tools_path\", \n    \"NO_PATH\", \n    \"--config-variable\", \n    \"replay_path\", \n    \"NO_PATH\", \n    \"--config-variable\", \n    \"xcode_arg_name\", \n    \"xcode-build-version\", \n    \"--config-variable\", \n    \"xcode_version\", \n    \"9abc\", \n    \"--config-variable\", \n    \"platform\", \n    \"fake device\", \n    \"--config-variable\", \n    \"version\", \n    \"8.1\"\n  ], \n  \"dir\": \"[START_DIR]\", \n  \"version\": 1\n}",
       "[CLEANUP]/isolate_tmp_1/0.isolated.gen.json"
     ],
     "cwd": "[START_DIR]/src",
@@ -456,6 +456,9 @@
       "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"test_args\", @@@",
       "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"[]\", @@@",
       "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"--config-variable\", @@@",
+      "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"xcode_parallelization\", @@@",
+      "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"false\", @@@",
+      "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"--config-variable\", @@@",
       "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"test_cases\", @@@",
       "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"[]\", @@@",
       "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"--config-variable\", @@@",
diff --git a/scripts/slave/recipe_modules/ios/examples/full.expected/test_failure.json b/scripts/slave/recipe_modules/ios/examples/full.expected/test_failure.json
index 3b8890a..4fe77f0 100644
--- a/scripts/slave/recipe_modules/ios/examples/full.expected/test_failure.json
+++ b/scripts/slave/recipe_modules/ios/examples/full.expected/test_failure.json
@@ -363,7 +363,7 @@
       "--json-output",
       "/path/to/tmp/json",
       "copy",
-      "{'conditions': [['OS == \"ios\"', {'variables': {'files': ['<(app_path)/', 'src/ios/build/bots/scripts/', 'src/out/Debug-iphonesimulator/iossim'], 'command': ['src/ios/build/bots/scripts/run.py', '--app', '<(app_path)', '--args-json', '{\"test_args\": <(test_args),         \"xctest\": <(xctest),         \"test_cases\": <(test_cases),         \"restart\": <(restart)}', '--out-dir', '${ISOLATED_OUTDIR}', '--retries', '3', '--shards', '<(shards)', '--<(xcode_arg_name)', '<(xcode_version)', '--mac-toolchain-cmd', './mac_toolchain', '--xcode-path', 'Xcode.app', '--wpr-tools-path', '<(wpr_tools_path)', '--replay-path', '<(replay_path)', '--iossim', 'src/out/Debug-iphonesimulator/iossim', '--platform', '<(platform)', '--version', '<(version)']}}]]}",
+      "{'conditions': [['OS == \"ios\"', {'variables': {'files': ['<(app_path)/', 'src/ios/build/bots/scripts/', 'src/out/Debug-iphonesimulator/iossim'], 'command': ['src/ios/build/bots/scripts/run.py', '--app', '<(app_path)', '--args-json', '{\"test_args\": <(test_args),         \"xctest\": <(xctest),         \"test_cases\": <(test_cases),         \"restart\": <(restart),         \"xcode-parallelization\": <(xcode_parallelization)}', '--out-dir', '${ISOLATED_OUTDIR}', '--retries', '3', '--shards', '<(shards)', '--<(xcode_arg_name)', '<(xcode_version)', '--mac-toolchain-cmd', './mac_toolchain', '--xcode-path', 'Xcode.app', '--wpr-tools-path', '<(wpr_tools_path)', '--replay-path', '<(replay_path)', '--iossim', 'src/out/Debug-iphonesimulator/iossim', '--platform', '<(platform)', '--version', '<(version)']}}]]}",
       "[START_DIR]/template.isolate"
     ],
     "cwd": "[START_DIR]/src",
@@ -382,7 +382,7 @@
       "@@@STEP_LOG_LINE@template.isolate@            \"--app\", @@@",
       "@@@STEP_LOG_LINE@template.isolate@            \"<(app_path)\", @@@",
       "@@@STEP_LOG_LINE@template.isolate@            \"--args-json\", @@@",
-      "@@@STEP_LOG_LINE@template.isolate@            \"{\\\"test_args\\\": <(test_args),         \\\"xctest\\\": <(xctest),         \\\"test_cases\\\": <(test_cases),         \\\"restart\\\": <(restart)}\", @@@",
+      "@@@STEP_LOG_LINE@template.isolate@            \"{\\\"test_args\\\": <(test_args),         \\\"xctest\\\": <(xctest),         \\\"test_cases\\\": <(test_cases),         \\\"restart\\\": <(restart),         \\\"xcode-parallelization\\\": <(xcode_parallelization)}\", @@@",
       "@@@STEP_LOG_LINE@template.isolate@            \"--out-dir\", @@@",
       "@@@STEP_LOG_LINE@template.isolate@            \"${ISOLATED_OUTDIR}\", @@@",
       "@@@STEP_LOG_LINE@template.isolate@            \"--retries\", @@@",
@@ -427,7 +427,7 @@
       "--json-output",
       "/path/to/tmp/json",
       "copy",
-      "{\n  \"args\": [\n    \"--config-variable\", \n    \"OS\", \n    \"ios\", \n    \"--config-variable\", \n    \"app_path\", \n    \"src/out/Debug-iphonesimulator/fake test.app\", \n    \"--config-variable\", \n    \"restart\", \n    \"false\", \n    \"--config-variable\", \n    \"shards\", \n    \"1\", \n    \"--config-variable\", \n    \"test_args\", \n    \"[]\", \n    \"--config-variable\", \n    \"test_cases\", \n    \"[]\", \n    \"--config-variable\", \n    \"xctest\", \n    \"false\", \n    \"--config-variable\", \n    \"use_trusted_cert\", \n    \"false\", \n    \"--isolate\", \n    \"[START_DIR]/template.isolate\", \n    \"--isolated\", \n    \"[CLEANUP]/isolate_tmp_1/0.isolated\", \n    \"--path-variable\", \n    \"app_path\", \n    \"src/out/Debug-iphonesimulator/fake test.app\", \n    \"--config-variable\", \n    \"wpr_tools_path\", \n    \"NO_PATH\", \n    \"--config-variable\", \n    \"replay_path\", \n    \"NO_PATH\", \n    \"--config-variable\", \n    \"xcode_arg_name\", \n    \"xcode-build-version\", \n    \"--config-variable\", \n    \"xcode_version\", \n    \"9abc\", \n    \"--config-variable\", \n    \"platform\", \n    \"fake device\", \n    \"--config-variable\", \n    \"version\", \n    \"8.1\"\n  ], \n  \"dir\": \"[START_DIR]\", \n  \"version\": 1\n}",
+      "{\n  \"args\": [\n    \"--config-variable\", \n    \"OS\", \n    \"ios\", \n    \"--config-variable\", \n    \"app_path\", \n    \"src/out/Debug-iphonesimulator/fake test.app\", \n    \"--config-variable\", \n    \"restart\", \n    \"false\", \n    \"--config-variable\", \n    \"shards\", \n    \"1\", \n    \"--config-variable\", \n    \"test_args\", \n    \"[]\", \n    \"--config-variable\", \n    \"xcode_parallelization\", \n    \"false\", \n    \"--config-variable\", \n    \"test_cases\", \n    \"[]\", \n    \"--config-variable\", \n    \"xctest\", \n    \"false\", \n    \"--config-variable\", \n    \"use_trusted_cert\", \n    \"false\", \n    \"--isolate\", \n    \"[START_DIR]/template.isolate\", \n    \"--isolated\", \n    \"[CLEANUP]/isolate_tmp_1/0.isolated\", \n    \"--path-variable\", \n    \"app_path\", \n    \"src/out/Debug-iphonesimulator/fake test.app\", \n    \"--config-variable\", \n    \"wpr_tools_path\", \n    \"NO_PATH\", \n    \"--config-variable\", \n    \"replay_path\", \n    \"NO_PATH\", \n    \"--config-variable\", \n    \"xcode_arg_name\", \n    \"xcode-build-version\", \n    \"--config-variable\", \n    \"xcode_version\", \n    \"9abc\", \n    \"--config-variable\", \n    \"platform\", \n    \"fake device\", \n    \"--config-variable\", \n    \"version\", \n    \"8.1\"\n  ], \n  \"dir\": \"[START_DIR]\", \n  \"version\": 1\n}",
       "[CLEANUP]/isolate_tmp_1/0.isolated.gen.json"
     ],
     "cwd": "[START_DIR]/src",
@@ -454,6 +454,9 @@
       "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"test_args\", @@@",
       "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"[]\", @@@",
       "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"--config-variable\", @@@",
+      "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"xcode_parallelization\", @@@",
+      "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"false\", @@@",
+      "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"--config-variable\", @@@",
       "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"test_cases\", @@@",
       "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"[]\", @@@",
       "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"--config-variable\", @@@",
diff --git a/scripts/slave/recipe_modules/ios/examples/full.expected/timed_out.json b/scripts/slave/recipe_modules/ios/examples/full.expected/timed_out.json
index d56ac64..bc61d9b 100644
--- a/scripts/slave/recipe_modules/ios/examples/full.expected/timed_out.json
+++ b/scripts/slave/recipe_modules/ios/examples/full.expected/timed_out.json
@@ -363,7 +363,7 @@
       "--json-output",
       "/path/to/tmp/json",
       "copy",
-      "{'conditions': [['OS == \"ios\"', {'variables': {'files': ['<(app_path)/', 'src/ios/build/bots/scripts/', 'src/out/Debug-iphonesimulator/iossim'], 'command': ['src/ios/build/bots/scripts/run.py', '--app', '<(app_path)', '--args-json', '{\"test_args\": <(test_args),         \"xctest\": <(xctest),         \"test_cases\": <(test_cases),         \"restart\": <(restart)}', '--out-dir', '${ISOLATED_OUTDIR}', '--retries', '3', '--shards', '<(shards)', '--<(xcode_arg_name)', '<(xcode_version)', '--mac-toolchain-cmd', './mac_toolchain', '--xcode-path', 'Xcode.app', '--wpr-tools-path', '<(wpr_tools_path)', '--replay-path', '<(replay_path)', '--iossim', 'src/out/Debug-iphonesimulator/iossim', '--platform', '<(platform)', '--version', '<(version)']}}]]}",
+      "{'conditions': [['OS == \"ios\"', {'variables': {'files': ['<(app_path)/', 'src/ios/build/bots/scripts/', 'src/out/Debug-iphonesimulator/iossim'], 'command': ['src/ios/build/bots/scripts/run.py', '--app', '<(app_path)', '--args-json', '{\"test_args\": <(test_args),         \"xctest\": <(xctest),         \"test_cases\": <(test_cases),         \"restart\": <(restart),         \"xcode-parallelization\": <(xcode_parallelization)}', '--out-dir', '${ISOLATED_OUTDIR}', '--retries', '3', '--shards', '<(shards)', '--<(xcode_arg_name)', '<(xcode_version)', '--mac-toolchain-cmd', './mac_toolchain', '--xcode-path', 'Xcode.app', '--wpr-tools-path', '<(wpr_tools_path)', '--replay-path', '<(replay_path)', '--iossim', 'src/out/Debug-iphonesimulator/iossim', '--platform', '<(platform)', '--version', '<(version)']}}]]}",
       "[START_DIR]/template.isolate"
     ],
     "cwd": "[START_DIR]/src",
@@ -382,7 +382,7 @@
       "@@@STEP_LOG_LINE@template.isolate@            \"--app\", @@@",
       "@@@STEP_LOG_LINE@template.isolate@            \"<(app_path)\", @@@",
       "@@@STEP_LOG_LINE@template.isolate@            \"--args-json\", @@@",
-      "@@@STEP_LOG_LINE@template.isolate@            \"{\\\"test_args\\\": <(test_args),         \\\"xctest\\\": <(xctest),         \\\"test_cases\\\": <(test_cases),         \\\"restart\\\": <(restart)}\", @@@",
+      "@@@STEP_LOG_LINE@template.isolate@            \"{\\\"test_args\\\": <(test_args),         \\\"xctest\\\": <(xctest),         \\\"test_cases\\\": <(test_cases),         \\\"restart\\\": <(restart),         \\\"xcode-parallelization\\\": <(xcode_parallelization)}\", @@@",
       "@@@STEP_LOG_LINE@template.isolate@            \"--out-dir\", @@@",
       "@@@STEP_LOG_LINE@template.isolate@            \"${ISOLATED_OUTDIR}\", @@@",
       "@@@STEP_LOG_LINE@template.isolate@            \"--retries\", @@@",
@@ -427,7 +427,7 @@
       "--json-output",
       "/path/to/tmp/json",
       "copy",
-      "{\n  \"args\": [\n    \"--config-variable\", \n    \"OS\", \n    \"ios\", \n    \"--config-variable\", \n    \"app_path\", \n    \"src/out/Debug-iphonesimulator/fake test.app\", \n    \"--config-variable\", \n    \"restart\", \n    \"false\", \n    \"--config-variable\", \n    \"shards\", \n    \"1\", \n    \"--config-variable\", \n    \"test_args\", \n    \"[]\", \n    \"--config-variable\", \n    \"test_cases\", \n    \"[]\", \n    \"--config-variable\", \n    \"xctest\", \n    \"false\", \n    \"--config-variable\", \n    \"use_trusted_cert\", \n    \"false\", \n    \"--isolate\", \n    \"[START_DIR]/template.isolate\", \n    \"--isolated\", \n    \"[CLEANUP]/isolate_tmp_1/0.isolated\", \n    \"--path-variable\", \n    \"app_path\", \n    \"src/out/Debug-iphonesimulator/fake test.app\", \n    \"--config-variable\", \n    \"wpr_tools_path\", \n    \"NO_PATH\", \n    \"--config-variable\", \n    \"replay_path\", \n    \"NO_PATH\", \n    \"--config-variable\", \n    \"xcode_arg_name\", \n    \"xcode-build-version\", \n    \"--config-variable\", \n    \"xcode_version\", \n    \"9abc\", \n    \"--config-variable\", \n    \"platform\", \n    \"fake device\", \n    \"--config-variable\", \n    \"version\", \n    \"8.1\"\n  ], \n  \"dir\": \"[START_DIR]\", \n  \"version\": 1\n}",
+      "{\n  \"args\": [\n    \"--config-variable\", \n    \"OS\", \n    \"ios\", \n    \"--config-variable\", \n    \"app_path\", \n    \"src/out/Debug-iphonesimulator/fake test.app\", \n    \"--config-variable\", \n    \"restart\", \n    \"false\", \n    \"--config-variable\", \n    \"shards\", \n    \"1\", \n    \"--config-variable\", \n    \"test_args\", \n    \"[]\", \n    \"--config-variable\", \n    \"xcode_parallelization\", \n    \"false\", \n    \"--config-variable\", \n    \"test_cases\", \n    \"[]\", \n    \"--config-variable\", \n    \"xctest\", \n    \"false\", \n    \"--config-variable\", \n    \"use_trusted_cert\", \n    \"false\", \n    \"--isolate\", \n    \"[START_DIR]/template.isolate\", \n    \"--isolated\", \n    \"[CLEANUP]/isolate_tmp_1/0.isolated\", \n    \"--path-variable\", \n    \"app_path\", \n    \"src/out/Debug-iphonesimulator/fake test.app\", \n    \"--config-variable\", \n    \"wpr_tools_path\", \n    \"NO_PATH\", \n    \"--config-variable\", \n    \"replay_path\", \n    \"NO_PATH\", \n    \"--config-variable\", \n    \"xcode_arg_name\", \n    \"xcode-build-version\", \n    \"--config-variable\", \n    \"xcode_version\", \n    \"9abc\", \n    \"--config-variable\", \n    \"platform\", \n    \"fake device\", \n    \"--config-variable\", \n    \"version\", \n    \"8.1\"\n  ], \n  \"dir\": \"[START_DIR]\", \n  \"version\": 1\n}",
       "[CLEANUP]/isolate_tmp_1/0.isolated.gen.json"
     ],
     "cwd": "[START_DIR]/src",
@@ -454,6 +454,9 @@
       "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"test_args\", @@@",
       "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"[]\", @@@",
       "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"--config-variable\", @@@",
+      "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"xcode_parallelization\", @@@",
+      "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"false\", @@@",
+      "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"--config-variable\", @@@",
       "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"test_cases\", @@@",
       "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"[]\", @@@",
       "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"--config-variable\", @@@",
diff --git a/scripts/slave/recipe_modules/ios/examples/full.expected/use_trusted_cert.json b/scripts/slave/recipe_modules/ios/examples/full.expected/use_trusted_cert.json
index 9738de4..e36b8ac 100644
--- a/scripts/slave/recipe_modules/ios/examples/full.expected/use_trusted_cert.json
+++ b/scripts/slave/recipe_modules/ios/examples/full.expected/use_trusted_cert.json
@@ -364,7 +364,7 @@
       "--json-output",
       "/path/to/tmp/json",
       "copy",
-      "{'conditions': [['OS == \"ios\"', {'variables': {'files': ['<(app_path)/', 'src/ios/build/bots/scripts/', 'src/out/Debug-iphonesimulator/iossim'], 'command': ['src/ios/build/bots/scripts/run.py', '--app', '<(app_path)', '--args-json', '{\"test_args\": <(test_args),         \"xctest\": <(xctest),         \"test_cases\": <(test_cases),         \"restart\": <(restart)}', '--out-dir', '${ISOLATED_OUTDIR}', '--retries', '3', '--shards', '<(shards)', '--<(xcode_arg_name)', '<(xcode_version)', '--mac-toolchain-cmd', './mac_toolchain', '--xcode-path', 'Xcode.app', '--wpr-tools-path', '<(wpr_tools_path)', '--replay-path', '<(replay_path)', '--iossim', 'src/out/Debug-iphonesimulator/iossim', '--platform', '<(platform)', '--version', '<(version)']}}]]}",
+      "{'conditions': [['OS == \"ios\"', {'variables': {'files': ['<(app_path)/', 'src/ios/build/bots/scripts/', 'src/out/Debug-iphonesimulator/iossim'], 'command': ['src/ios/build/bots/scripts/run.py', '--app', '<(app_path)', '--args-json', '{\"test_args\": <(test_args),         \"xctest\": <(xctest),         \"test_cases\": <(test_cases),         \"restart\": <(restart),         \"xcode-parallelization\": <(xcode_parallelization)}', '--out-dir', '${ISOLATED_OUTDIR}', '--retries', '3', '--shards', '<(shards)', '--<(xcode_arg_name)', '<(xcode_version)', '--mac-toolchain-cmd', './mac_toolchain', '--xcode-path', 'Xcode.app', '--wpr-tools-path', '<(wpr_tools_path)', '--replay-path', '<(replay_path)', '--iossim', 'src/out/Debug-iphonesimulator/iossim', '--platform', '<(platform)', '--version', '<(version)']}}]]}",
       "[START_DIR]/template.isolate"
     ],
     "cwd": "[START_DIR]/src",
@@ -383,7 +383,7 @@
       "@@@STEP_LOG_LINE@template.isolate@            \"--app\", @@@",
       "@@@STEP_LOG_LINE@template.isolate@            \"<(app_path)\", @@@",
       "@@@STEP_LOG_LINE@template.isolate@            \"--args-json\", @@@",
-      "@@@STEP_LOG_LINE@template.isolate@            \"{\\\"test_args\\\": <(test_args),         \\\"xctest\\\": <(xctest),         \\\"test_cases\\\": <(test_cases),         \\\"restart\\\": <(restart)}\", @@@",
+      "@@@STEP_LOG_LINE@template.isolate@            \"{\\\"test_args\\\": <(test_args),         \\\"xctest\\\": <(xctest),         \\\"test_cases\\\": <(test_cases),         \\\"restart\\\": <(restart),         \\\"xcode-parallelization\\\": <(xcode_parallelization)}\", @@@",
       "@@@STEP_LOG_LINE@template.isolate@            \"--out-dir\", @@@",
       "@@@STEP_LOG_LINE@template.isolate@            \"${ISOLATED_OUTDIR}\", @@@",
       "@@@STEP_LOG_LINE@template.isolate@            \"--retries\", @@@",
@@ -428,7 +428,7 @@
       "--json-output",
       "/path/to/tmp/json",
       "copy",
-      "{\n  \"args\": [\n    \"--config-variable\", \n    \"OS\", \n    \"ios\", \n    \"--config-variable\", \n    \"app_path\", \n    \"src/out/Debug-iphonesimulator/fake test.app\", \n    \"--config-variable\", \n    \"restart\", \n    \"false\", \n    \"--config-variable\", \n    \"shards\", \n    \"1\", \n    \"--config-variable\", \n    \"test_args\", \n    \"[]\", \n    \"--config-variable\", \n    \"test_cases\", \n    \"[]\", \n    \"--config-variable\", \n    \"xctest\", \n    \"false\", \n    \"--config-variable\", \n    \"use_trusted_cert\", \n    \"true\", \n    \"--isolate\", \n    \"[START_DIR]/template.isolate\", \n    \"--isolated\", \n    \"[CLEANUP]/isolate_tmp_1/0.isolated\", \n    \"--path-variable\", \n    \"app_path\", \n    \"src/out/Debug-iphonesimulator/fake test.app\", \n    \"--config-variable\", \n    \"wpr_tools_path\", \n    \"wpr-ios-tools\", \n    \"--config-variable\", \n    \"replay_path\", \n    \"NO_PATH\", \n    \"--config-variable\", \n    \"xcode_arg_name\", \n    \"xcode-build-version\", \n    \"--config-variable\", \n    \"xcode_version\", \n    \"9abc\", \n    \"--config-variable\", \n    \"platform\", \n    \"fake device\", \n    \"--config-variable\", \n    \"version\", \n    \"8.1\"\n  ], \n  \"dir\": \"[START_DIR]\", \n  \"version\": 1\n}",
+      "{\n  \"args\": [\n    \"--config-variable\", \n    \"OS\", \n    \"ios\", \n    \"--config-variable\", \n    \"app_path\", \n    \"src/out/Debug-iphonesimulator/fake test.app\", \n    \"--config-variable\", \n    \"restart\", \n    \"false\", \n    \"--config-variable\", \n    \"shards\", \n    \"1\", \n    \"--config-variable\", \n    \"test_args\", \n    \"[]\", \n    \"--config-variable\", \n    \"xcode_parallelization\", \n    \"false\", \n    \"--config-variable\", \n    \"test_cases\", \n    \"[]\", \n    \"--config-variable\", \n    \"xctest\", \n    \"false\", \n    \"--config-variable\", \n    \"use_trusted_cert\", \n    \"true\", \n    \"--isolate\", \n    \"[START_DIR]/template.isolate\", \n    \"--isolated\", \n    \"[CLEANUP]/isolate_tmp_1/0.isolated\", \n    \"--path-variable\", \n    \"app_path\", \n    \"src/out/Debug-iphonesimulator/fake test.app\", \n    \"--config-variable\", \n    \"wpr_tools_path\", \n    \"wpr-ios-tools\", \n    \"--config-variable\", \n    \"replay_path\", \n    \"NO_PATH\", \n    \"--config-variable\", \n    \"xcode_arg_name\", \n    \"xcode-build-version\", \n    \"--config-variable\", \n    \"xcode_version\", \n    \"9abc\", \n    \"--config-variable\", \n    \"platform\", \n    \"fake device\", \n    \"--config-variable\", \n    \"version\", \n    \"8.1\"\n  ], \n  \"dir\": \"[START_DIR]\", \n  \"version\": 1\n}",
       "[CLEANUP]/isolate_tmp_1/0.isolated.gen.json"
     ],
     "cwd": "[START_DIR]/src",
@@ -455,6 +455,9 @@
       "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"test_args\", @@@",
       "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"[]\", @@@",
       "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"--config-variable\", @@@",
+      "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"xcode_parallelization\", @@@",
+      "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"false\", @@@",
+      "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"--config-variable\", @@@",
       "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"test_cases\", @@@",
       "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"[]\", @@@",
       "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"--config-variable\", @@@",
diff --git a/scripts/slave/recipe_modules/ios/examples/full.expected/use_wpr_tools.json b/scripts/slave/recipe_modules/ios/examples/full.expected/use_wpr_tools.json
index 5aa23c5..4529dff 100644
--- a/scripts/slave/recipe_modules/ios/examples/full.expected/use_wpr_tools.json
+++ b/scripts/slave/recipe_modules/ios/examples/full.expected/use_wpr_tools.json
@@ -369,7 +369,7 @@
       "--json-output",
       "/path/to/tmp/json",
       "copy",
-      "{'conditions': [['OS == \"ios\"', {'variables': {'files': ['<(app_path)/', 'src/ios/build/bots/scripts/', 'fake/file/path1/', 'fake/file/path2/', 'src/out/Debug-iphonesimulator/iossim'], 'command': ['src/ios/build/bots/scripts/run.py', '--app', '<(app_path)', '--args-json', '{\"test_args\": <(test_args),         \"xctest\": <(xctest),         \"test_cases\": <(test_cases),         \"restart\": <(restart)}', '--out-dir', '${ISOLATED_OUTDIR}', '--retries', '3', '--shards', '<(shards)', '--<(xcode_arg_name)', '<(xcode_version)', '--mac-toolchain-cmd', './mac_toolchain', '--xcode-path', 'Xcode.app', '--wpr-tools-path', '<(wpr_tools_path)', '--replay-path', '<(replay_path)', '--iossim', 'src/out/Debug-iphonesimulator/iossim', '--platform', '<(platform)', '--version', '<(version)']}}]]}",
+      "{'conditions': [['OS == \"ios\"', {'variables': {'files': ['<(app_path)/', 'src/ios/build/bots/scripts/', 'fake/file/path1/', 'fake/file/path2/', 'src/out/Debug-iphonesimulator/iossim'], 'command': ['src/ios/build/bots/scripts/run.py', '--app', '<(app_path)', '--args-json', '{\"test_args\": <(test_args),         \"xctest\": <(xctest),         \"test_cases\": <(test_cases),         \"restart\": <(restart),         \"xcode-parallelization\": <(xcode_parallelization)}', '--out-dir', '${ISOLATED_OUTDIR}', '--retries', '3', '--shards', '<(shards)', '--<(xcode_arg_name)', '<(xcode_version)', '--mac-toolchain-cmd', './mac_toolchain', '--xcode-path', 'Xcode.app', '--wpr-tools-path', '<(wpr_tools_path)', '--replay-path', '<(replay_path)', '--iossim', 'src/out/Debug-iphonesimulator/iossim', '--platform', '<(platform)', '--version', '<(version)']}}]]}",
       "[START_DIR]/template.isolate"
     ],
     "cwd": "[START_DIR]/src",
@@ -388,7 +388,7 @@
       "@@@STEP_LOG_LINE@template.isolate@            \"--app\", @@@",
       "@@@STEP_LOG_LINE@template.isolate@            \"<(app_path)\", @@@",
       "@@@STEP_LOG_LINE@template.isolate@            \"--args-json\", @@@",
-      "@@@STEP_LOG_LINE@template.isolate@            \"{\\\"test_args\\\": <(test_args),         \\\"xctest\\\": <(xctest),         \\\"test_cases\\\": <(test_cases),         \\\"restart\\\": <(restart)}\", @@@",
+      "@@@STEP_LOG_LINE@template.isolate@            \"{\\\"test_args\\\": <(test_args),         \\\"xctest\\\": <(xctest),         \\\"test_cases\\\": <(test_cases),         \\\"restart\\\": <(restart),         \\\"xcode-parallelization\\\": <(xcode_parallelization)}\", @@@",
       "@@@STEP_LOG_LINE@template.isolate@            \"--out-dir\", @@@",
       "@@@STEP_LOG_LINE@template.isolate@            \"${ISOLATED_OUTDIR}\", @@@",
       "@@@STEP_LOG_LINE@template.isolate@            \"--retries\", @@@",
@@ -435,7 +435,7 @@
       "--json-output",
       "/path/to/tmp/json",
       "copy",
-      "{\n  \"args\": [\n    \"--config-variable\", \n    \"OS\", \n    \"ios\", \n    \"--config-variable\", \n    \"app_path\", \n    \"src/out/Debug-iphonesimulator/fake test.app\", \n    \"--config-variable\", \n    \"restart\", \n    \"false\", \n    \"--config-variable\", \n    \"shards\", \n    \"1\", \n    \"--config-variable\", \n    \"test_args\", \n    \"[]\", \n    \"--config-variable\", \n    \"test_cases\", \n    \"[]\", \n    \"--config-variable\", \n    \"xctest\", \n    \"false\", \n    \"--config-variable\", \n    \"use_trusted_cert\", \n    \"false\", \n    \"--isolate\", \n    \"[START_DIR]/template.isolate\", \n    \"--isolated\", \n    \"[CLEANUP]/isolate_tmp_1/0.isolated\", \n    \"--path-variable\", \n    \"app_path\", \n    \"src/out/Debug-iphonesimulator/fake test.app\", \n    \"--config-variable\", \n    \"wpr_tools_path\", \n    \"wpr-ios-tools\", \n    \"--config-variable\", \n    \"replay_path\", \n    \"wpr-replay-data\", \n    \"--config-variable\", \n    \"xcode_arg_name\", \n    \"xcode-build-version\", \n    \"--config-variable\", \n    \"xcode_version\", \n    \"9abc\", \n    \"--config-variable\", \n    \"platform\", \n    \"fake device\", \n    \"--config-variable\", \n    \"version\", \n    \"8.1\"\n  ], \n  \"dir\": \"[START_DIR]\", \n  \"version\": 1\n}",
+      "{\n  \"args\": [\n    \"--config-variable\", \n    \"OS\", \n    \"ios\", \n    \"--config-variable\", \n    \"app_path\", \n    \"src/out/Debug-iphonesimulator/fake test.app\", \n    \"--config-variable\", \n    \"restart\", \n    \"false\", \n    \"--config-variable\", \n    \"shards\", \n    \"1\", \n    \"--config-variable\", \n    \"test_args\", \n    \"[]\", \n    \"--config-variable\", \n    \"xcode_parallelization\", \n    \"false\", \n    \"--config-variable\", \n    \"test_cases\", \n    \"[]\", \n    \"--config-variable\", \n    \"xctest\", \n    \"false\", \n    \"--config-variable\", \n    \"use_trusted_cert\", \n    \"false\", \n    \"--isolate\", \n    \"[START_DIR]/template.isolate\", \n    \"--isolated\", \n    \"[CLEANUP]/isolate_tmp_1/0.isolated\", \n    \"--path-variable\", \n    \"app_path\", \n    \"src/out/Debug-iphonesimulator/fake test.app\", \n    \"--config-variable\", \n    \"wpr_tools_path\", \n    \"wpr-ios-tools\", \n    \"--config-variable\", \n    \"replay_path\", \n    \"wpr-replay-data\", \n    \"--config-variable\", \n    \"xcode_arg_name\", \n    \"xcode-build-version\", \n    \"--config-variable\", \n    \"xcode_version\", \n    \"9abc\", \n    \"--config-variable\", \n    \"platform\", \n    \"fake device\", \n    \"--config-variable\", \n    \"version\", \n    \"8.1\"\n  ], \n  \"dir\": \"[START_DIR]\", \n  \"version\": 1\n}",
       "[CLEANUP]/isolate_tmp_1/0.isolated.gen.json"
     ],
     "cwd": "[START_DIR]/src",
@@ -462,6 +462,9 @@
       "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"test_args\", @@@",
       "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"[]\", @@@",
       "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"--config-variable\", @@@",
+      "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"xcode_parallelization\", @@@",
+      "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"false\", @@@",
+      "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"--config-variable\", @@@",
       "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"test_cases\", @@@",
       "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"[]\", @@@",
       "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"--config-variable\", @@@",
diff --git a/scripts/slave/recipe_modules/ios/examples/full.expected/xcode_build_version.json b/scripts/slave/recipe_modules/ios/examples/full.expected/xcode_build_version.json
index e47ea96..b2845ed 100644
--- a/scripts/slave/recipe_modules/ios/examples/full.expected/xcode_build_version.json
+++ b/scripts/slave/recipe_modules/ios/examples/full.expected/xcode_build_version.json
@@ -377,7 +377,7 @@
       "--json-output",
       "/path/to/tmp/json",
       "copy",
-      "{'conditions': [['OS == \"ios\"', {'variables': {'files': ['<(app_path)/', 'src/ios/build/bots/scripts/', 'src/out/Debug-iphonesimulator/iossim'], 'command': ['src/ios/build/bots/scripts/run.py', '--app', '<(app_path)', '--args-json', '{\"test_args\": <(test_args),         \"xctest\": <(xctest),         \"test_cases\": <(test_cases),         \"restart\": <(restart)}', '--out-dir', '${ISOLATED_OUTDIR}', '--retries', '3', '--shards', '<(shards)', '--<(xcode_arg_name)', '<(xcode_version)', '--mac-toolchain-cmd', './mac_toolchain', '--xcode-path', 'Xcode.app', '--wpr-tools-path', '<(wpr_tools_path)', '--replay-path', '<(replay_path)', '--iossim', 'src/out/Debug-iphonesimulator/iossim', '--platform', '<(platform)', '--version', '<(version)']}}]]}",
+      "{'conditions': [['OS == \"ios\"', {'variables': {'files': ['<(app_path)/', 'src/ios/build/bots/scripts/', 'src/out/Debug-iphonesimulator/iossim'], 'command': ['src/ios/build/bots/scripts/run.py', '--app', '<(app_path)', '--args-json', '{\"test_args\": <(test_args),         \"xctest\": <(xctest),         \"test_cases\": <(test_cases),         \"restart\": <(restart),         \"xcode-parallelization\": <(xcode_parallelization)}', '--out-dir', '${ISOLATED_OUTDIR}', '--retries', '3', '--shards', '<(shards)', '--<(xcode_arg_name)', '<(xcode_version)', '--mac-toolchain-cmd', './mac_toolchain', '--xcode-path', 'Xcode.app', '--wpr-tools-path', '<(wpr_tools_path)', '--replay-path', '<(replay_path)', '--iossim', 'src/out/Debug-iphonesimulator/iossim', '--platform', '<(platform)', '--version', '<(version)']}}]]}",
       "[START_DIR]/template.isolate"
     ],
     "cwd": "[START_DIR]/src",
@@ -396,7 +396,7 @@
       "@@@STEP_LOG_LINE@template.isolate@            \"--app\", @@@",
       "@@@STEP_LOG_LINE@template.isolate@            \"<(app_path)\", @@@",
       "@@@STEP_LOG_LINE@template.isolate@            \"--args-json\", @@@",
-      "@@@STEP_LOG_LINE@template.isolate@            \"{\\\"test_args\\\": <(test_args),         \\\"xctest\\\": <(xctest),         \\\"test_cases\\\": <(test_cases),         \\\"restart\\\": <(restart)}\", @@@",
+      "@@@STEP_LOG_LINE@template.isolate@            \"{\\\"test_args\\\": <(test_args),         \\\"xctest\\\": <(xctest),         \\\"test_cases\\\": <(test_cases),         \\\"restart\\\": <(restart),         \\\"xcode-parallelization\\\": <(xcode_parallelization)}\", @@@",
       "@@@STEP_LOG_LINE@template.isolate@            \"--out-dir\", @@@",
       "@@@STEP_LOG_LINE@template.isolate@            \"${ISOLATED_OUTDIR}\", @@@",
       "@@@STEP_LOG_LINE@template.isolate@            \"--retries\", @@@",
@@ -441,7 +441,7 @@
       "--json-output",
       "/path/to/tmp/json",
       "copy",
-      "{\n  \"args\": [\n    \"--config-variable\", \n    \"OS\", \n    \"ios\", \n    \"--config-variable\", \n    \"app_path\", \n    \"src/out/Debug-iphonesimulator/build-global xcode build version.app\", \n    \"--config-variable\", \n    \"restart\", \n    \"false\", \n    \"--config-variable\", \n    \"shards\", \n    \"1\", \n    \"--config-variable\", \n    \"test_args\", \n    \"[]\", \n    \"--config-variable\", \n    \"test_cases\", \n    \"[]\", \n    \"--config-variable\", \n    \"xctest\", \n    \"false\", \n    \"--config-variable\", \n    \"use_trusted_cert\", \n    \"false\", \n    \"--isolate\", \n    \"[START_DIR]/template.isolate\", \n    \"--isolated\", \n    \"[CLEANUP]/isolate_tmp_1/0.isolated\", \n    \"--path-variable\", \n    \"app_path\", \n    \"src/out/Debug-iphonesimulator/build-global xcode build version.app\", \n    \"--config-variable\", \n    \"wpr_tools_path\", \n    \"NO_PATH\", \n    \"--config-variable\", \n    \"replay_path\", \n    \"NO_PATH\", \n    \"--config-variable\", \n    \"xcode_arg_name\", \n    \"xcode-build-version\", \n    \"--config-variable\", \n    \"xcode_version\", \n    \"9a123\", \n    \"--config-variable\", \n    \"platform\", \n    \"fake device\", \n    \"--config-variable\", \n    \"version\", \n    \"10.0\"\n  ], \n  \"dir\": \"[START_DIR]\", \n  \"version\": 1\n}",
+      "{\n  \"args\": [\n    \"--config-variable\", \n    \"OS\", \n    \"ios\", \n    \"--config-variable\", \n    \"app_path\", \n    \"src/out/Debug-iphonesimulator/build-global xcode build version.app\", \n    \"--config-variable\", \n    \"restart\", \n    \"false\", \n    \"--config-variable\", \n    \"shards\", \n    \"1\", \n    \"--config-variable\", \n    \"test_args\", \n    \"[]\", \n    \"--config-variable\", \n    \"xcode_parallelization\", \n    \"false\", \n    \"--config-variable\", \n    \"test_cases\", \n    \"[]\", \n    \"--config-variable\", \n    \"xctest\", \n    \"false\", \n    \"--config-variable\", \n    \"use_trusted_cert\", \n    \"false\", \n    \"--isolate\", \n    \"[START_DIR]/template.isolate\", \n    \"--isolated\", \n    \"[CLEANUP]/isolate_tmp_1/0.isolated\", \n    \"--path-variable\", \n    \"app_path\", \n    \"src/out/Debug-iphonesimulator/build-global xcode build version.app\", \n    \"--config-variable\", \n    \"wpr_tools_path\", \n    \"NO_PATH\", \n    \"--config-variable\", \n    \"replay_path\", \n    \"NO_PATH\", \n    \"--config-variable\", \n    \"xcode_arg_name\", \n    \"xcode-build-version\", \n    \"--config-variable\", \n    \"xcode_version\", \n    \"9a123\", \n    \"--config-variable\", \n    \"platform\", \n    \"fake device\", \n    \"--config-variable\", \n    \"version\", \n    \"10.0\"\n  ], \n  \"dir\": \"[START_DIR]\", \n  \"version\": 1\n}",
       "[CLEANUP]/isolate_tmp_1/0.isolated.gen.json"
     ],
     "cwd": "[START_DIR]/src",
@@ -468,6 +468,9 @@
       "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"test_args\", @@@",
       "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"[]\", @@@",
       "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"--config-variable\", @@@",
+      "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"xcode_parallelization\", @@@",
+      "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"false\", @@@",
+      "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"--config-variable\", @@@",
       "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"test_cases\", @@@",
       "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"[]\", @@@",
       "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"--config-variable\", @@@",
@@ -516,7 +519,7 @@
       "--json-output",
       "/path/to/tmp/json",
       "copy",
-      "{\n  \"args\": [\n    \"--config-variable\", \n    \"OS\", \n    \"ios\", \n    \"--config-variable\", \n    \"app_path\", \n    \"src/out/Debug-iphonesimulator/task-local xcode build version.app\", \n    \"--config-variable\", \n    \"restart\", \n    \"false\", \n    \"--config-variable\", \n    \"shards\", \n    \"1\", \n    \"--config-variable\", \n    \"test_args\", \n    \"[]\", \n    \"--config-variable\", \n    \"test_cases\", \n    \"[]\", \n    \"--config-variable\", \n    \"xctest\", \n    \"false\", \n    \"--config-variable\", \n    \"use_trusted_cert\", \n    \"false\", \n    \"--isolate\", \n    \"[START_DIR]/template.isolate\", \n    \"--isolated\", \n    \"[CLEANUP]/isolate_tmp_1/1.isolated\", \n    \"--path-variable\", \n    \"app_path\", \n    \"src/out/Debug-iphonesimulator/task-local xcode build version.app\", \n    \"--config-variable\", \n    \"wpr_tools_path\", \n    \"NO_PATH\", \n    \"--config-variable\", \n    \"replay_path\", \n    \"NO_PATH\", \n    \"--config-variable\", \n    \"xcode_arg_name\", \n    \"xcode-build-version\", \n    \"--config-variable\", \n    \"xcode_version\", \n    \"9b456\", \n    \"--config-variable\", \n    \"platform\", \n    \"fake device 2\", \n    \"--config-variable\", \n    \"version\", \n    \"11.0\"\n  ], \n  \"dir\": \"[START_DIR]\", \n  \"version\": 1\n}",
+      "{\n  \"args\": [\n    \"--config-variable\", \n    \"OS\", \n    \"ios\", \n    \"--config-variable\", \n    \"app_path\", \n    \"src/out/Debug-iphonesimulator/task-local xcode build version.app\", \n    \"--config-variable\", \n    \"restart\", \n    \"false\", \n    \"--config-variable\", \n    \"shards\", \n    \"1\", \n    \"--config-variable\", \n    \"test_args\", \n    \"[]\", \n    \"--config-variable\", \n    \"xcode_parallelization\", \n    \"false\", \n    \"--config-variable\", \n    \"test_cases\", \n    \"[]\", \n    \"--config-variable\", \n    \"xctest\", \n    \"false\", \n    \"--config-variable\", \n    \"use_trusted_cert\", \n    \"false\", \n    \"--isolate\", \n    \"[START_DIR]/template.isolate\", \n    \"--isolated\", \n    \"[CLEANUP]/isolate_tmp_1/1.isolated\", \n    \"--path-variable\", \n    \"app_path\", \n    \"src/out/Debug-iphonesimulator/task-local xcode build version.app\", \n    \"--config-variable\", \n    \"wpr_tools_path\", \n    \"NO_PATH\", \n    \"--config-variable\", \n    \"replay_path\", \n    \"NO_PATH\", \n    \"--config-variable\", \n    \"xcode_arg_name\", \n    \"xcode-build-version\", \n    \"--config-variable\", \n    \"xcode_version\", \n    \"9b456\", \n    \"--config-variable\", \n    \"platform\", \n    \"fake device 2\", \n    \"--config-variable\", \n    \"version\", \n    \"11.0\"\n  ], \n  \"dir\": \"[START_DIR]\", \n  \"version\": 1\n}",
       "[CLEANUP]/isolate_tmp_1/1.isolated.gen.json"
     ],
     "cwd": "[START_DIR]/src",
@@ -543,6 +546,9 @@
       "@@@STEP_LOG_LINE@1.isolated.gen.json@    \"test_args\", @@@",
       "@@@STEP_LOG_LINE@1.isolated.gen.json@    \"[]\", @@@",
       "@@@STEP_LOG_LINE@1.isolated.gen.json@    \"--config-variable\", @@@",
+      "@@@STEP_LOG_LINE@1.isolated.gen.json@    \"xcode_parallelization\", @@@",
+      "@@@STEP_LOG_LINE@1.isolated.gen.json@    \"false\", @@@",
+      "@@@STEP_LOG_LINE@1.isolated.gen.json@    \"--config-variable\", @@@",
       "@@@STEP_LOG_LINE@1.isolated.gen.json@    \"test_cases\", @@@",
       "@@@STEP_LOG_LINE@1.isolated.gen.json@    \"[]\", @@@",
       "@@@STEP_LOG_LINE@1.isolated.gen.json@    \"--config-variable\", @@@",
@@ -601,7 +607,7 @@
       "--json-output",
       "/path/to/tmp/json",
       "copy",
-      "{\n  \"args\": [\n    \"--config-variable\", \n    \"OS\", \n    \"ios\", \n    \"--config-variable\", \n    \"app_path\", \n    \"src/out/Debug-iphonesimulator/task-local xcode version.app\", \n    \"--config-variable\", \n    \"restart\", \n    \"false\", \n    \"--config-variable\", \n    \"shards\", \n    \"1\", \n    \"--config-variable\", \n    \"test_args\", \n    \"[]\", \n    \"--config-variable\", \n    \"test_cases\", \n    \"[]\", \n    \"--config-variable\", \n    \"xctest\", \n    \"false\", \n    \"--config-variable\", \n    \"use_trusted_cert\", \n    \"false\", \n    \"--isolate\", \n    \"[START_DIR]/template.isolate\", \n    \"--isolated\", \n    \"[CLEANUP]/isolate_tmp_1/2.isolated\", \n    \"--path-variable\", \n    \"app_path\", \n    \"src/out/Debug-iphonesimulator/task-local xcode version.app\", \n    \"--config-variable\", \n    \"wpr_tools_path\", \n    \"NO_PATH\", \n    \"--config-variable\", \n    \"replay_path\", \n    \"NO_PATH\", \n    \"--config-variable\", \n    \"xcode_arg_name\", \n    \"xcode-build-version\", \n    \"--config-variable\", \n    \"xcode_version\", \n    \"9c40b\", \n    \"--config-variable\", \n    \"platform\", \n    \"fake device 3\", \n    \"--config-variable\", \n    \"version\", \n    \"11.0\"\n  ], \n  \"dir\": \"[START_DIR]\", \n  \"version\": 1\n}",
+      "{\n  \"args\": [\n    \"--config-variable\", \n    \"OS\", \n    \"ios\", \n    \"--config-variable\", \n    \"app_path\", \n    \"src/out/Debug-iphonesimulator/task-local xcode version.app\", \n    \"--config-variable\", \n    \"restart\", \n    \"false\", \n    \"--config-variable\", \n    \"shards\", \n    \"1\", \n    \"--config-variable\", \n    \"test_args\", \n    \"[]\", \n    \"--config-variable\", \n    \"xcode_parallelization\", \n    \"false\", \n    \"--config-variable\", \n    \"test_cases\", \n    \"[]\", \n    \"--config-variable\", \n    \"xctest\", \n    \"false\", \n    \"--config-variable\", \n    \"use_trusted_cert\", \n    \"false\", \n    \"--isolate\", \n    \"[START_DIR]/template.isolate\", \n    \"--isolated\", \n    \"[CLEANUP]/isolate_tmp_1/2.isolated\", \n    \"--path-variable\", \n    \"app_path\", \n    \"src/out/Debug-iphonesimulator/task-local xcode version.app\", \n    \"--config-variable\", \n    \"wpr_tools_path\", \n    \"NO_PATH\", \n    \"--config-variable\", \n    \"replay_path\", \n    \"NO_PATH\", \n    \"--config-variable\", \n    \"xcode_arg_name\", \n    \"xcode-build-version\", \n    \"--config-variable\", \n    \"xcode_version\", \n    \"9c40b\", \n    \"--config-variable\", \n    \"platform\", \n    \"fake device 3\", \n    \"--config-variable\", \n    \"version\", \n    \"11.0\"\n  ], \n  \"dir\": \"[START_DIR]\", \n  \"version\": 1\n}",
       "[CLEANUP]/isolate_tmp_1/2.isolated.gen.json"
     ],
     "cwd": "[START_DIR]/src",
@@ -628,6 +634,9 @@
       "@@@STEP_LOG_LINE@2.isolated.gen.json@    \"test_args\", @@@",
       "@@@STEP_LOG_LINE@2.isolated.gen.json@    \"[]\", @@@",
       "@@@STEP_LOG_LINE@2.isolated.gen.json@    \"--config-variable\", @@@",
+      "@@@STEP_LOG_LINE@2.isolated.gen.json@    \"xcode_parallelization\", @@@",
+      "@@@STEP_LOG_LINE@2.isolated.gen.json@    \"false\", @@@",
+      "@@@STEP_LOG_LINE@2.isolated.gen.json@    \"--config-variable\", @@@",
       "@@@STEP_LOG_LINE@2.isolated.gen.json@    \"test_cases\", @@@",
       "@@@STEP_LOG_LINE@2.isolated.gen.json@    \"[]\", @@@",
       "@@@STEP_LOG_LINE@2.isolated.gen.json@    \"--config-variable\", @@@",
diff --git a/scripts/slave/recipe_modules/ios/examples/full.expected/xcode_build_version_luci.json b/scripts/slave/recipe_modules/ios/examples/full.expected/xcode_build_version_luci.json
index 5ae413d..7e9b11b 100644
--- a/scripts/slave/recipe_modules/ios/examples/full.expected/xcode_build_version_luci.json
+++ b/scripts/slave/recipe_modules/ios/examples/full.expected/xcode_build_version_luci.json
@@ -376,7 +376,7 @@
       "--json-output",
       "/path/to/tmp/json",
       "copy",
-      "{'conditions': [['OS == \"ios\"', {'variables': {'files': ['<(app_path)/', 'src/ios/build/bots/scripts/', 'src/out/Debug-iphonesimulator/iossim'], 'command': ['src/ios/build/bots/scripts/run.py', '--app', '<(app_path)', '--args-json', '{\"test_args\": <(test_args),         \"xctest\": <(xctest),         \"test_cases\": <(test_cases),         \"restart\": <(restart)}', '--out-dir', '${ISOLATED_OUTDIR}', '--retries', '3', '--shards', '<(shards)', '--<(xcode_arg_name)', '<(xcode_version)', '--mac-toolchain-cmd', './mac_toolchain', '--xcode-path', 'Xcode.app', '--wpr-tools-path', '<(wpr_tools_path)', '--replay-path', '<(replay_path)', '--iossim', 'src/out/Debug-iphonesimulator/iossim', '--platform', '<(platform)', '--version', '<(version)']}}]]}",
+      "{'conditions': [['OS == \"ios\"', {'variables': {'files': ['<(app_path)/', 'src/ios/build/bots/scripts/', 'src/out/Debug-iphonesimulator/iossim'], 'command': ['src/ios/build/bots/scripts/run.py', '--app', '<(app_path)', '--args-json', '{\"test_args\": <(test_args),         \"xctest\": <(xctest),         \"test_cases\": <(test_cases),         \"restart\": <(restart),         \"xcode-parallelization\": <(xcode_parallelization)}', '--out-dir', '${ISOLATED_OUTDIR}', '--retries', '3', '--shards', '<(shards)', '--<(xcode_arg_name)', '<(xcode_version)', '--mac-toolchain-cmd', './mac_toolchain', '--xcode-path', 'Xcode.app', '--wpr-tools-path', '<(wpr_tools_path)', '--replay-path', '<(replay_path)', '--iossim', 'src/out/Debug-iphonesimulator/iossim', '--platform', '<(platform)', '--version', '<(version)']}}]]}",
       "[CACHE]/builder/template.isolate"
     ],
     "cwd": "[CACHE]/builder/src",
@@ -395,7 +395,7 @@
       "@@@STEP_LOG_LINE@template.isolate@            \"--app\", @@@",
       "@@@STEP_LOG_LINE@template.isolate@            \"<(app_path)\", @@@",
       "@@@STEP_LOG_LINE@template.isolate@            \"--args-json\", @@@",
-      "@@@STEP_LOG_LINE@template.isolate@            \"{\\\"test_args\\\": <(test_args),         \\\"xctest\\\": <(xctest),         \\\"test_cases\\\": <(test_cases),         \\\"restart\\\": <(restart)}\", @@@",
+      "@@@STEP_LOG_LINE@template.isolate@            \"{\\\"test_args\\\": <(test_args),         \\\"xctest\\\": <(xctest),         \\\"test_cases\\\": <(test_cases),         \\\"restart\\\": <(restart),         \\\"xcode-parallelization\\\": <(xcode_parallelization)}\", @@@",
       "@@@STEP_LOG_LINE@template.isolate@            \"--out-dir\", @@@",
       "@@@STEP_LOG_LINE@template.isolate@            \"${ISOLATED_OUTDIR}\", @@@",
       "@@@STEP_LOG_LINE@template.isolate@            \"--retries\", @@@",
@@ -440,7 +440,7 @@
       "--json-output",
       "/path/to/tmp/json",
       "copy",
-      "{\n  \"args\": [\n    \"--config-variable\", \n    \"OS\", \n    \"ios\", \n    \"--config-variable\", \n    \"app_path\", \n    \"src/out/Debug-iphonesimulator/build-global xcode build version.app\", \n    \"--config-variable\", \n    \"restart\", \n    \"false\", \n    \"--config-variable\", \n    \"shards\", \n    \"1\", \n    \"--config-variable\", \n    \"test_args\", \n    \"[]\", \n    \"--config-variable\", \n    \"test_cases\", \n    \"[]\", \n    \"--config-variable\", \n    \"xctest\", \n    \"false\", \n    \"--config-variable\", \n    \"use_trusted_cert\", \n    \"false\", \n    \"--isolate\", \n    \"[CACHE]/builder/template.isolate\", \n    \"--isolated\", \n    \"[CLEANUP]/isolate_tmp_1/0.isolated\", \n    \"--path-variable\", \n    \"app_path\", \n    \"src/out/Debug-iphonesimulator/build-global xcode build version.app\", \n    \"--config-variable\", \n    \"wpr_tools_path\", \n    \"NO_PATH\", \n    \"--config-variable\", \n    \"replay_path\", \n    \"NO_PATH\", \n    \"--config-variable\", \n    \"xcode_arg_name\", \n    \"xcode-build-version\", \n    \"--config-variable\", \n    \"xcode_version\", \n    \"9a123\", \n    \"--config-variable\", \n    \"platform\", \n    \"fake device\", \n    \"--config-variable\", \n    \"version\", \n    \"10.0\"\n  ], \n  \"dir\": \"[CACHE]/builder\", \n  \"version\": 1\n}",
+      "{\n  \"args\": [\n    \"--config-variable\", \n    \"OS\", \n    \"ios\", \n    \"--config-variable\", \n    \"app_path\", \n    \"src/out/Debug-iphonesimulator/build-global xcode build version.app\", \n    \"--config-variable\", \n    \"restart\", \n    \"false\", \n    \"--config-variable\", \n    \"shards\", \n    \"1\", \n    \"--config-variable\", \n    \"test_args\", \n    \"[]\", \n    \"--config-variable\", \n    \"xcode_parallelization\", \n    \"false\", \n    \"--config-variable\", \n    \"test_cases\", \n    \"[]\", \n    \"--config-variable\", \n    \"xctest\", \n    \"false\", \n    \"--config-variable\", \n    \"use_trusted_cert\", \n    \"false\", \n    \"--isolate\", \n    \"[CACHE]/builder/template.isolate\", \n    \"--isolated\", \n    \"[CLEANUP]/isolate_tmp_1/0.isolated\", \n    \"--path-variable\", \n    \"app_path\", \n    \"src/out/Debug-iphonesimulator/build-global xcode build version.app\", \n    \"--config-variable\", \n    \"wpr_tools_path\", \n    \"NO_PATH\", \n    \"--config-variable\", \n    \"replay_path\", \n    \"NO_PATH\", \n    \"--config-variable\", \n    \"xcode_arg_name\", \n    \"xcode-build-version\", \n    \"--config-variable\", \n    \"xcode_version\", \n    \"9a123\", \n    \"--config-variable\", \n    \"platform\", \n    \"fake device\", \n    \"--config-variable\", \n    \"version\", \n    \"10.0\"\n  ], \n  \"dir\": \"[CACHE]/builder\", \n  \"version\": 1\n}",
       "[CLEANUP]/isolate_tmp_1/0.isolated.gen.json"
     ],
     "cwd": "[CACHE]/builder/src",
@@ -467,6 +467,9 @@
       "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"test_args\", @@@",
       "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"[]\", @@@",
       "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"--config-variable\", @@@",
+      "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"xcode_parallelization\", @@@",
+      "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"false\", @@@",
+      "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"--config-variable\", @@@",
       "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"test_cases\", @@@",
       "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"[]\", @@@",
       "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"--config-variable\", @@@",
@@ -515,7 +518,7 @@
       "--json-output",
       "/path/to/tmp/json",
       "copy",
-      "{\n  \"args\": [\n    \"--config-variable\", \n    \"OS\", \n    \"ios\", \n    \"--config-variable\", \n    \"app_path\", \n    \"src/out/Debug-iphonesimulator/task-local xcode build version.app\", \n    \"--config-variable\", \n    \"restart\", \n    \"false\", \n    \"--config-variable\", \n    \"shards\", \n    \"1\", \n    \"--config-variable\", \n    \"test_args\", \n    \"[]\", \n    \"--config-variable\", \n    \"test_cases\", \n    \"[]\", \n    \"--config-variable\", \n    \"xctest\", \n    \"false\", \n    \"--config-variable\", \n    \"use_trusted_cert\", \n    \"false\", \n    \"--isolate\", \n    \"[CACHE]/builder/template.isolate\", \n    \"--isolated\", \n    \"[CLEANUP]/isolate_tmp_1/1.isolated\", \n    \"--path-variable\", \n    \"app_path\", \n    \"src/out/Debug-iphonesimulator/task-local xcode build version.app\", \n    \"--config-variable\", \n    \"wpr_tools_path\", \n    \"NO_PATH\", \n    \"--config-variable\", \n    \"replay_path\", \n    \"NO_PATH\", \n    \"--config-variable\", \n    \"xcode_arg_name\", \n    \"xcode-build-version\", \n    \"--config-variable\", \n    \"xcode_version\", \n    \"9b456\", \n    \"--config-variable\", \n    \"platform\", \n    \"fake device 2\", \n    \"--config-variable\", \n    \"version\", \n    \"11.0\"\n  ], \n  \"dir\": \"[CACHE]/builder\", \n  \"version\": 1\n}",
+      "{\n  \"args\": [\n    \"--config-variable\", \n    \"OS\", \n    \"ios\", \n    \"--config-variable\", \n    \"app_path\", \n    \"src/out/Debug-iphonesimulator/task-local xcode build version.app\", \n    \"--config-variable\", \n    \"restart\", \n    \"false\", \n    \"--config-variable\", \n    \"shards\", \n    \"1\", \n    \"--config-variable\", \n    \"test_args\", \n    \"[]\", \n    \"--config-variable\", \n    \"xcode_parallelization\", \n    \"false\", \n    \"--config-variable\", \n    \"test_cases\", \n    \"[]\", \n    \"--config-variable\", \n    \"xctest\", \n    \"false\", \n    \"--config-variable\", \n    \"use_trusted_cert\", \n    \"false\", \n    \"--isolate\", \n    \"[CACHE]/builder/template.isolate\", \n    \"--isolated\", \n    \"[CLEANUP]/isolate_tmp_1/1.isolated\", \n    \"--path-variable\", \n    \"app_path\", \n    \"src/out/Debug-iphonesimulator/task-local xcode build version.app\", \n    \"--config-variable\", \n    \"wpr_tools_path\", \n    \"NO_PATH\", \n    \"--config-variable\", \n    \"replay_path\", \n    \"NO_PATH\", \n    \"--config-variable\", \n    \"xcode_arg_name\", \n    \"xcode-build-version\", \n    \"--config-variable\", \n    \"xcode_version\", \n    \"9b456\", \n    \"--config-variable\", \n    \"platform\", \n    \"fake device 2\", \n    \"--config-variable\", \n    \"version\", \n    \"11.0\"\n  ], \n  \"dir\": \"[CACHE]/builder\", \n  \"version\": 1\n}",
       "[CLEANUP]/isolate_tmp_1/1.isolated.gen.json"
     ],
     "cwd": "[CACHE]/builder/src",
@@ -542,6 +545,9 @@
       "@@@STEP_LOG_LINE@1.isolated.gen.json@    \"test_args\", @@@",
       "@@@STEP_LOG_LINE@1.isolated.gen.json@    \"[]\", @@@",
       "@@@STEP_LOG_LINE@1.isolated.gen.json@    \"--config-variable\", @@@",
+      "@@@STEP_LOG_LINE@1.isolated.gen.json@    \"xcode_parallelization\", @@@",
+      "@@@STEP_LOG_LINE@1.isolated.gen.json@    \"false\", @@@",
+      "@@@STEP_LOG_LINE@1.isolated.gen.json@    \"--config-variable\", @@@",
       "@@@STEP_LOG_LINE@1.isolated.gen.json@    \"test_cases\", @@@",
       "@@@STEP_LOG_LINE@1.isolated.gen.json@    \"[]\", @@@",
       "@@@STEP_LOG_LINE@1.isolated.gen.json@    \"--config-variable\", @@@",
@@ -600,7 +606,7 @@
       "--json-output",
       "/path/to/tmp/json",
       "copy",
-      "{\n  \"args\": [\n    \"--config-variable\", \n    \"OS\", \n    \"ios\", \n    \"--config-variable\", \n    \"app_path\", \n    \"src/out/Debug-iphonesimulator/task-local xcode version.app\", \n    \"--config-variable\", \n    \"restart\", \n    \"false\", \n    \"--config-variable\", \n    \"shards\", \n    \"1\", \n    \"--config-variable\", \n    \"test_args\", \n    \"[]\", \n    \"--config-variable\", \n    \"test_cases\", \n    \"[]\", \n    \"--config-variable\", \n    \"xctest\", \n    \"false\", \n    \"--config-variable\", \n    \"use_trusted_cert\", \n    \"false\", \n    \"--isolate\", \n    \"[CACHE]/builder/template.isolate\", \n    \"--isolated\", \n    \"[CLEANUP]/isolate_tmp_1/2.isolated\", \n    \"--path-variable\", \n    \"app_path\", \n    \"src/out/Debug-iphonesimulator/task-local xcode version.app\", \n    \"--config-variable\", \n    \"wpr_tools_path\", \n    \"NO_PATH\", \n    \"--config-variable\", \n    \"replay_path\", \n    \"NO_PATH\", \n    \"--config-variable\", \n    \"xcode_arg_name\", \n    \"xcode-build-version\", \n    \"--config-variable\", \n    \"xcode_version\", \n    \"9c40b\", \n    \"--config-variable\", \n    \"platform\", \n    \"fake device 3\", \n    \"--config-variable\", \n    \"version\", \n    \"11.0\"\n  ], \n  \"dir\": \"[CACHE]/builder\", \n  \"version\": 1\n}",
+      "{\n  \"args\": [\n    \"--config-variable\", \n    \"OS\", \n    \"ios\", \n    \"--config-variable\", \n    \"app_path\", \n    \"src/out/Debug-iphonesimulator/task-local xcode version.app\", \n    \"--config-variable\", \n    \"restart\", \n    \"false\", \n    \"--config-variable\", \n    \"shards\", \n    \"1\", \n    \"--config-variable\", \n    \"test_args\", \n    \"[]\", \n    \"--config-variable\", \n    \"xcode_parallelization\", \n    \"false\", \n    \"--config-variable\", \n    \"test_cases\", \n    \"[]\", \n    \"--config-variable\", \n    \"xctest\", \n    \"false\", \n    \"--config-variable\", \n    \"use_trusted_cert\", \n    \"false\", \n    \"--isolate\", \n    \"[CACHE]/builder/template.isolate\", \n    \"--isolated\", \n    \"[CLEANUP]/isolate_tmp_1/2.isolated\", \n    \"--path-variable\", \n    \"app_path\", \n    \"src/out/Debug-iphonesimulator/task-local xcode version.app\", \n    \"--config-variable\", \n    \"wpr_tools_path\", \n    \"NO_PATH\", \n    \"--config-variable\", \n    \"replay_path\", \n    \"NO_PATH\", \n    \"--config-variable\", \n    \"xcode_arg_name\", \n    \"xcode-build-version\", \n    \"--config-variable\", \n    \"xcode_version\", \n    \"9c40b\", \n    \"--config-variable\", \n    \"platform\", \n    \"fake device 3\", \n    \"--config-variable\", \n    \"version\", \n    \"11.0\"\n  ], \n  \"dir\": \"[CACHE]/builder\", \n  \"version\": 1\n}",
       "[CLEANUP]/isolate_tmp_1/2.isolated.gen.json"
     ],
     "cwd": "[CACHE]/builder/src",
@@ -627,6 +633,9 @@
       "@@@STEP_LOG_LINE@2.isolated.gen.json@    \"test_args\", @@@",
       "@@@STEP_LOG_LINE@2.isolated.gen.json@    \"[]\", @@@",
       "@@@STEP_LOG_LINE@2.isolated.gen.json@    \"--config-variable\", @@@",
+      "@@@STEP_LOG_LINE@2.isolated.gen.json@    \"xcode_parallelization\", @@@",
+      "@@@STEP_LOG_LINE@2.isolated.gen.json@    \"false\", @@@",
+      "@@@STEP_LOG_LINE@2.isolated.gen.json@    \"--config-variable\", @@@",
       "@@@STEP_LOG_LINE@2.isolated.gen.json@    \"test_cases\", @@@",
       "@@@STEP_LOG_LINE@2.isolated.gen.json@    \"[]\", @@@",
       "@@@STEP_LOG_LINE@2.isolated.gen.json@    \"--config-variable\", @@@",
diff --git a/scripts/slave/recipe_modules/ios/examples/full.expected/xparallel_run.json b/scripts/slave/recipe_modules/ios/examples/full.expected/xparallel_run.json
deleted file mode 100644
index aae7768..0000000
--- a/scripts/slave/recipe_modules/ios/examples/full.expected/xparallel_run.json
+++ /dev/null
@@ -1,783 +0,0 @@
-[
-  {
-    "cmd": [
-      "python",
-      "-u",
-      "RECIPE_MODULE[depot_tools::bot_update]/resources/bot_update.py",
-      "--spec-path",
-      "cache_dir = '[CACHE]/git'\nsolutions = [{'custom_vars': {'checkout_telemetry_dependencies': 'True'}, 'deps_file': '.DEPS.git', 'managed': True, 'name': 'src', 'url': 'https://chromium.googlesource.com/chromium/src.git'}]\ntarget_os = ['ios']",
-      "--revision_mapping_file",
-      "{\"got_angle_revision\": \"src/third_party/angle\", \"got_buildtools_revision\": \"src/buildtools\", \"got_dawn_revision\": \"src/third_party/dawn\", \"got_nacl_revision\": \"src/native_client\", \"got_revision\": \"src\", \"got_swarming_client_revision\": \"src/tools/swarming_client\", \"got_v8_revision\": \"src/v8\", \"got_webrtc_revision\": \"src/third_party/webrtc\"}",
-      "--git-cache-dir",
-      "[CACHE]/git",
-      "--cleanup-dir",
-      "[CLEANUP]/bot_update",
-      "--output_json",
-      "/path/to/tmp/json",
-      "--revision",
-      "src@HEAD"
-    ],
-    "env_prefixes": {
-      "PATH": [
-        "RECIPE_PACKAGE_REPO[depot_tools]"
-      ]
-    },
-    "infra_step": true,
-    "name": "bot_update",
-    "~followup_annotations": [
-      "@@@STEP_TEXT@Some step text@@@",
-      "@@@STEP_LOG_LINE@json.output@{@@@",
-      "@@@STEP_LOG_LINE@json.output@  \"did_run\": true, @@@",
-      "@@@STEP_LOG_LINE@json.output@  \"fixed_revisions\": {@@@",
-      "@@@STEP_LOG_LINE@json.output@    \"src\": \"HEAD\"@@@",
-      "@@@STEP_LOG_LINE@json.output@  }, @@@",
-      "@@@STEP_LOG_LINE@json.output@  \"manifest\": {@@@",
-      "@@@STEP_LOG_LINE@json.output@    \"src\": {@@@",
-      "@@@STEP_LOG_LINE@json.output@      \"repository\": \"https://fake.org/src.git\", @@@",
-      "@@@STEP_LOG_LINE@json.output@      \"revision\": \"f27fede2220bcd326aee3e86ddfd4ebd0fe58cb9\"@@@",
-      "@@@STEP_LOG_LINE@json.output@    }, @@@",
-      "@@@STEP_LOG_LINE@json.output@    \"src/buildtools\": {@@@",
-      "@@@STEP_LOG_LINE@json.output@      \"repository\": \"https://fake.org/src/buildtools.git\", @@@",
-      "@@@STEP_LOG_LINE@json.output@      \"revision\": \"f0319a328b2809876916353cb994259692140934\"@@@",
-      "@@@STEP_LOG_LINE@json.output@    }, @@@",
-      "@@@STEP_LOG_LINE@json.output@    \"src/native_client\": {@@@",
-      "@@@STEP_LOG_LINE@json.output@      \"repository\": \"https://fake.org/src/native_client.git\", @@@",
-      "@@@STEP_LOG_LINE@json.output@      \"revision\": \"d998e125e8253980d76e269b7982aeeefc1b9b50\"@@@",
-      "@@@STEP_LOG_LINE@json.output@    }, @@@",
-      "@@@STEP_LOG_LINE@json.output@    \"src/third_party/angle\": {@@@",
-      "@@@STEP_LOG_LINE@json.output@      \"repository\": \"https://fake.org/src/third_party/angle.git\", @@@",
-      "@@@STEP_LOG_LINE@json.output@      \"revision\": \"fac9503c46405f77757b9a728eb85b8d7bc6080c\"@@@",
-      "@@@STEP_LOG_LINE@json.output@    }, @@@",
-      "@@@STEP_LOG_LINE@json.output@    \"src/third_party/dawn\": {@@@",
-      "@@@STEP_LOG_LINE@json.output@      \"repository\": \"https://fake.org/src/third_party/dawn.git\", @@@",
-      "@@@STEP_LOG_LINE@json.output@      \"revision\": \"1b5c932bc9a9a35c66edea3914fb675742d57cc2\"@@@",
-      "@@@STEP_LOG_LINE@json.output@    }, @@@",
-      "@@@STEP_LOG_LINE@json.output@    \"src/third_party/webrtc\": {@@@",
-      "@@@STEP_LOG_LINE@json.output@      \"repository\": \"https://fake.org/src/third_party/webrtc.git\", @@@",
-      "@@@STEP_LOG_LINE@json.output@      \"revision\": \"0f90628433546e61d9268596da93418c623137f4\"@@@",
-      "@@@STEP_LOG_LINE@json.output@    }, @@@",
-      "@@@STEP_LOG_LINE@json.output@    \"src/tools/swarming_client\": {@@@",
-      "@@@STEP_LOG_LINE@json.output@      \"repository\": \"https://fake.org/src/tools/swarming_client.git\", @@@",
-      "@@@STEP_LOG_LINE@json.output@      \"revision\": \"a0ee5d99f1d4b38ddaa4c759c837980b63b99566\"@@@",
-      "@@@STEP_LOG_LINE@json.output@    }, @@@",
-      "@@@STEP_LOG_LINE@json.output@    \"src/v8\": {@@@",
-      "@@@STEP_LOG_LINE@json.output@      \"repository\": \"https://fake.org/src/v8.git\", @@@",
-      "@@@STEP_LOG_LINE@json.output@      \"revision\": \"801ada225ddc271c132c3a35f03975671d43e399\"@@@",
-      "@@@STEP_LOG_LINE@json.output@    }@@@",
-      "@@@STEP_LOG_LINE@json.output@  }, @@@",
-      "@@@STEP_LOG_LINE@json.output@  \"patch_failure\": false, @@@",
-      "@@@STEP_LOG_LINE@json.output@  \"patch_root\": \"src\", @@@",
-      "@@@STEP_LOG_LINE@json.output@  \"properties\": {@@@",
-      "@@@STEP_LOG_LINE@json.output@    \"got_angle_revision\": \"fac9503c46405f77757b9a728eb85b8d7bc6080c\", @@@",
-      "@@@STEP_LOG_LINE@json.output@    \"got_angle_revision_cp\": \"refs/heads/master@{#297276}\", @@@",
-      "@@@STEP_LOG_LINE@json.output@    \"got_buildtools_revision\": \"f0319a328b2809876916353cb994259692140934\", @@@",
-      "@@@STEP_LOG_LINE@json.output@    \"got_buildtools_revision_cp\": \"refs/heads/master@{#182578}\", @@@",
-      "@@@STEP_LOG_LINE@json.output@    \"got_dawn_revision\": \"1b5c932bc9a9a35c66edea3914fb675742d57cc2\", @@@",
-      "@@@STEP_LOG_LINE@json.output@    \"got_dawn_revision_cp\": \"refs/heads/master@{#51819}\", @@@",
-      "@@@STEP_LOG_LINE@json.output@    \"got_nacl_revision\": \"d998e125e8253980d76e269b7982aeeefc1b9b50\", @@@",
-      "@@@STEP_LOG_LINE@json.output@    \"got_nacl_revision_cp\": \"refs/heads/master@{#274981}\", @@@",
-      "@@@STEP_LOG_LINE@json.output@    \"got_revision\": \"f27fede2220bcd326aee3e86ddfd4ebd0fe58cb9\", @@@",
-      "@@@STEP_LOG_LINE@json.output@    \"got_revision_cp\": \"refs/heads/master@{#170242}\", @@@",
-      "@@@STEP_LOG_LINE@json.output@    \"got_swarming_client_revision\": \"a0ee5d99f1d4b38ddaa4c759c837980b63b99566\", @@@",
-      "@@@STEP_LOG_LINE@json.output@    \"got_swarming_client_revision_cp\": \"refs/heads/master@{#276089}\", @@@",
-      "@@@STEP_LOG_LINE@json.output@    \"got_v8_revision\": \"801ada225ddc271c132c3a35f03975671d43e399\", @@@",
-      "@@@STEP_LOG_LINE@json.output@    \"got_v8_revision_cp\": \"refs/heads/master@{#43426}\", @@@",
-      "@@@STEP_LOG_LINE@json.output@    \"got_webrtc_revision\": \"0f90628433546e61d9268596da93418c623137f4\", @@@",
-      "@@@STEP_LOG_LINE@json.output@    \"got_webrtc_revision_cp\": \"refs/heads/master@{#120644}\"@@@",
-      "@@@STEP_LOG_LINE@json.output@  }, @@@",
-      "@@@STEP_LOG_LINE@json.output@  \"root\": \"src\", @@@",
-      "@@@STEP_LOG_LINE@json.output@  \"source_manifest\": {@@@",
-      "@@@STEP_LOG_LINE@json.output@    \"directories\": {@@@",
-      "@@@STEP_LOG_LINE@json.output@      \"src\": {@@@",
-      "@@@STEP_LOG_LINE@json.output@        \"git_checkout\": {@@@",
-      "@@@STEP_LOG_LINE@json.output@          \"repo_url\": \"https://fake.org/src.git\", @@@",
-      "@@@STEP_LOG_LINE@json.output@          \"revision\": \"f27fede2220bcd326aee3e86ddfd4ebd0fe58cb9\"@@@",
-      "@@@STEP_LOG_LINE@json.output@        }@@@",
-      "@@@STEP_LOG_LINE@json.output@      }, @@@",
-      "@@@STEP_LOG_LINE@json.output@      \"src/buildtools\": {@@@",
-      "@@@STEP_LOG_LINE@json.output@        \"git_checkout\": {@@@",
-      "@@@STEP_LOG_LINE@json.output@          \"repo_url\": \"https://fake.org/src/buildtools.git\", @@@",
-      "@@@STEP_LOG_LINE@json.output@          \"revision\": \"f0319a328b2809876916353cb994259692140934\"@@@",
-      "@@@STEP_LOG_LINE@json.output@        }@@@",
-      "@@@STEP_LOG_LINE@json.output@      }, @@@",
-      "@@@STEP_LOG_LINE@json.output@      \"src/native_client\": {@@@",
-      "@@@STEP_LOG_LINE@json.output@        \"git_checkout\": {@@@",
-      "@@@STEP_LOG_LINE@json.output@          \"repo_url\": \"https://fake.org/src/native_client.git\", @@@",
-      "@@@STEP_LOG_LINE@json.output@          \"revision\": \"d998e125e8253980d76e269b7982aeeefc1b9b50\"@@@",
-      "@@@STEP_LOG_LINE@json.output@        }@@@",
-      "@@@STEP_LOG_LINE@json.output@      }, @@@",
-      "@@@STEP_LOG_LINE@json.output@      \"src/third_party/angle\": {@@@",
-      "@@@STEP_LOG_LINE@json.output@        \"git_checkout\": {@@@",
-      "@@@STEP_LOG_LINE@json.output@          \"repo_url\": \"https://fake.org/src/third_party/angle.git\", @@@",
-      "@@@STEP_LOG_LINE@json.output@          \"revision\": \"fac9503c46405f77757b9a728eb85b8d7bc6080c\"@@@",
-      "@@@STEP_LOG_LINE@json.output@        }@@@",
-      "@@@STEP_LOG_LINE@json.output@      }, @@@",
-      "@@@STEP_LOG_LINE@json.output@      \"src/third_party/dawn\": {@@@",
-      "@@@STEP_LOG_LINE@json.output@        \"git_checkout\": {@@@",
-      "@@@STEP_LOG_LINE@json.output@          \"repo_url\": \"https://fake.org/src/third_party/dawn.git\", @@@",
-      "@@@STEP_LOG_LINE@json.output@          \"revision\": \"1b5c932bc9a9a35c66edea3914fb675742d57cc2\"@@@",
-      "@@@STEP_LOG_LINE@json.output@        }@@@",
-      "@@@STEP_LOG_LINE@json.output@      }, @@@",
-      "@@@STEP_LOG_LINE@json.output@      \"src/third_party/webrtc\": {@@@",
-      "@@@STEP_LOG_LINE@json.output@        \"git_checkout\": {@@@",
-      "@@@STEP_LOG_LINE@json.output@          \"repo_url\": \"https://fake.org/src/third_party/webrtc.git\", @@@",
-      "@@@STEP_LOG_LINE@json.output@          \"revision\": \"0f90628433546e61d9268596da93418c623137f4\"@@@",
-      "@@@STEP_LOG_LINE@json.output@        }@@@",
-      "@@@STEP_LOG_LINE@json.output@      }, @@@",
-      "@@@STEP_LOG_LINE@json.output@      \"src/tools/swarming_client\": {@@@",
-      "@@@STEP_LOG_LINE@json.output@        \"git_checkout\": {@@@",
-      "@@@STEP_LOG_LINE@json.output@          \"repo_url\": \"https://fake.org/src/tools/swarming_client.git\", @@@",
-      "@@@STEP_LOG_LINE@json.output@          \"revision\": \"a0ee5d99f1d4b38ddaa4c759c837980b63b99566\"@@@",
-      "@@@STEP_LOG_LINE@json.output@        }@@@",
-      "@@@STEP_LOG_LINE@json.output@      }, @@@",
-      "@@@STEP_LOG_LINE@json.output@      \"src/v8\": {@@@",
-      "@@@STEP_LOG_LINE@json.output@        \"git_checkout\": {@@@",
-      "@@@STEP_LOG_LINE@json.output@          \"repo_url\": \"https://fake.org/src/v8.git\", @@@",
-      "@@@STEP_LOG_LINE@json.output@          \"revision\": \"801ada225ddc271c132c3a35f03975671d43e399\"@@@",
-      "@@@STEP_LOG_LINE@json.output@        }@@@",
-      "@@@STEP_LOG_LINE@json.output@      }@@@",
-      "@@@STEP_LOG_LINE@json.output@    }, @@@",
-      "@@@STEP_LOG_LINE@json.output@    \"version\": 0@@@",
-      "@@@STEP_LOG_LINE@json.output@  }, @@@",
-      "@@@STEP_LOG_LINE@json.output@  \"step_text\": \"Some step text\"@@@",
-      "@@@STEP_LOG_LINE@json.output@}@@@",
-      "@@@STEP_LOG_END@json.output@@@",
-      "@@@SET_BUILD_PROPERTY@got_angle_revision@\"fac9503c46405f77757b9a728eb85b8d7bc6080c\"@@@",
-      "@@@SET_BUILD_PROPERTY@got_angle_revision_cp@\"refs/heads/master@{#297276}\"@@@",
-      "@@@SET_BUILD_PROPERTY@got_buildtools_revision@\"f0319a328b2809876916353cb994259692140934\"@@@",
-      "@@@SET_BUILD_PROPERTY@got_buildtools_revision_cp@\"refs/heads/master@{#182578}\"@@@",
-      "@@@SET_BUILD_PROPERTY@got_dawn_revision@\"1b5c932bc9a9a35c66edea3914fb675742d57cc2\"@@@",
-      "@@@SET_BUILD_PROPERTY@got_dawn_revision_cp@\"refs/heads/master@{#51819}\"@@@",
-      "@@@SET_BUILD_PROPERTY@got_nacl_revision@\"d998e125e8253980d76e269b7982aeeefc1b9b50\"@@@",
-      "@@@SET_BUILD_PROPERTY@got_nacl_revision_cp@\"refs/heads/master@{#274981}\"@@@",
-      "@@@SET_BUILD_PROPERTY@got_revision@\"f27fede2220bcd326aee3e86ddfd4ebd0fe58cb9\"@@@",
-      "@@@SET_BUILD_PROPERTY@got_revision_cp@\"refs/heads/master@{#170242}\"@@@",
-      "@@@SET_BUILD_PROPERTY@got_swarming_client_revision@\"a0ee5d99f1d4b38ddaa4c759c837980b63b99566\"@@@",
-      "@@@SET_BUILD_PROPERTY@got_swarming_client_revision_cp@\"refs/heads/master@{#276089}\"@@@",
-      "@@@SET_BUILD_PROPERTY@got_v8_revision@\"801ada225ddc271c132c3a35f03975671d43e399\"@@@",
-      "@@@SET_BUILD_PROPERTY@got_v8_revision_cp@\"refs/heads/master@{#43426}\"@@@",
-      "@@@SET_BUILD_PROPERTY@got_webrtc_revision@\"0f90628433546e61d9268596da93418c623137f4\"@@@",
-      "@@@SET_BUILD_PROPERTY@got_webrtc_revision_cp@\"refs/heads/master@{#120644}\"@@@"
-    ]
-  },
-  {
-    "cmd": [
-      "python",
-      "-u",
-      "\nimport shutil\nimport sys\nshutil.copy(sys.argv[1], sys.argv[2])\n",
-      "[START_DIR]/src/ios/build/bots/chromium.fyi/ios.json",
-      "/path/to/tmp/json"
-    ],
-    "name": "read build config",
-    "~followup_annotations": [
-      "@@@STEP_LOG_LINE@json.output@{@@@",
-      "@@@STEP_LOG_LINE@json.output@  \"additional files\": [@@@",
-      "@@@STEP_LOG_LINE@json.output@    \"fake/file/path1/\", @@@",
-      "@@@STEP_LOG_LINE@json.output@    \"fake/file/path2/\"@@@",
-      "@@@STEP_LOG_LINE@json.output@  ], @@@",
-      "@@@STEP_LOG_LINE@json.output@  \"gn_args\": [@@@",
-      "@@@STEP_LOG_LINE@json.output@    \"is_debug=true\", @@@",
-      "@@@STEP_LOG_LINE@json.output@    \"target_cpu=\\\"x86\\\"\"@@@",
-      "@@@STEP_LOG_LINE@json.output@  ], @@@",
-      "@@@STEP_LOG_LINE@json.output@  \"tests\": [@@@",
-      "@@@STEP_LOG_LINE@json.output@    {@@@",
-      "@@@STEP_LOG_LINE@json.output@      \"app\": \"fake test\", @@@",
-      "@@@STEP_LOG_LINE@json.output@      \"device type\": \"fake device\", @@@",
-      "@@@STEP_LOG_LINE@json.output@      \"os\": \"12.0.1\", @@@",
-      "@@@STEP_LOG_LINE@json.output@      \"shards\": 4@@@",
-      "@@@STEP_LOG_LINE@json.output@    }@@@",
-      "@@@STEP_LOG_LINE@json.output@  ], @@@",
-      "@@@STEP_LOG_LINE@json.output@  \"xcode build version\": \"09a123\", @@@",
-      "@@@STEP_LOG_LINE@json.output@  \"xcode parallelization\": true@@@",
-      "@@@STEP_LOG_LINE@json.output@}@@@",
-      "@@@STEP_LOG_END@json.output@@@"
-    ]
-  },
-  {
-    "cmd": [],
-    "name": "ensure xcode",
-    "~followup_annotations": [
-      "@@@STEP_TEXT@Ensuring Xcode version 09a123 in [CACHE]/xcode_ios_09a123.app@@@"
-    ]
-  },
-  {
-    "cmd": [
-      "cipd",
-      "ensure",
-      "-root",
-      "[START_DIR]",
-      "-ensure-file",
-      "infra/tools/mac_toolchain/${platform} git_revision:796d2b92cff93fc2059623ce0a66284373ceea0a",
-      "-json-output",
-      "/path/to/tmp/json"
-    ],
-    "name": "ensure xcode.ensure_installed",
-    "~followup_annotations": [
-      "@@@STEP_NEST_LEVEL@1@@@",
-      "@@@STEP_LOG_LINE@json.output@{@@@",
-      "@@@STEP_LOG_LINE@json.output@  \"result\": [@@@",
-      "@@@STEP_LOG_LINE@json.output@    {@@@",
-      "@@@STEP_LOG_LINE@json.output@      \"instance_id\": \"resolved-instance_id-of-git_revision:796\", @@@",
-      "@@@STEP_LOG_LINE@json.output@      \"package\": \"infra/tools/mac_toolchain/${platform}\"@@@",
-      "@@@STEP_LOG_LINE@json.output@    }@@@",
-      "@@@STEP_LOG_LINE@json.output@  ]@@@",
-      "@@@STEP_LOG_LINE@json.output@}@@@",
-      "@@@STEP_LOG_END@json.output@@@"
-    ]
-  },
-  {
-    "cmd": [
-      "[START_DIR]/mac_toolchain",
-      "install",
-      "-kind",
-      "ios",
-      "-xcode-version",
-      "09a123",
-      "-output-dir",
-      "[CACHE]/xcode_ios_09a123.app",
-      "-service-account-json",
-      "/creds/service_accounts/service-account-xcode-cipd-access.json"
-    ],
-    "infra_step": true,
-    "name": "ensure xcode.install xcode",
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-      "@@@STEP_NEST_LEVEL@1@@@"
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-  },
-  {
-    "cmd": [
-      "sudo",
-      "xcode-select",
-      "-switch",
-      "[CACHE]/xcode_ios_09a123.app"
-    ],
-    "infra_step": true,
-    "name": "ensure xcode.select xcode",
-    "~followup_annotations": [
-      "@@@STEP_NEST_LEVEL@1@@@"
-    ]
-  },
-  {
-    "cmd": [
-      "python",
-      "-u",
-      "RECIPE_PACKAGE_REPO[depot_tools]/gclient.py",
-      "runhooks"
-    ],
-    "cwd": "[START_DIR]/src",
-    "env": {
-      "FORCE_MAC_TOOLCHAIN": "",
-      "LANDMINES_VERBOSE": "1"
-    },
-    "env_suffixes": {
-      "PATH": [
-        "RECIPE_PACKAGE_REPO[depot_tools]"
-      ]
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-    "cmd": [
-      "python",
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-      "RECIPE_MODULE[recipe_engine::file]/resources/fileutil.py",
-      "--json-output",
-      "/path/to/tmp/json",
-      "ensure-directory",
-      "--mode",
-      "0777",
-      "[START_DIR]/src/out/Debug-iphonesimulator"
-    ],
-    "infra_step": true,
-    "name": "ensure_directory //out/Debug-iphonesimulator"
-  },
-  {
-    "cmd": [
-      "python",
-      "-u",
-      "RECIPE_MODULE[recipe_engine::file]/resources/fileutil.py",
-      "--json-output",
-      "/path/to/tmp/json",
-      "copy",
-      "is_debug=true\ntarget_cpu=\"x86\"\n",
-      "[START_DIR]/src/out/Debug-iphonesimulator/args.gn"
-    ],
-    "infra_step": true,
-    "name": "write args.gn",
-    "~followup_annotations": [
-      "@@@STEP_TEXT@<br />is_debug=true<br />target_cpu=\"x86\"@@@"
-    ]
-  },
-  {
-    "cmd": [
-      "[START_DIR]/src/buildtools/mac/gn",
-      "gen",
-      "--check",
-      "//out/Debug-iphonesimulator"
-    ],
-    "cwd": "[START_DIR]/src/out/Debug-iphonesimulator",
-    "env": {
-      "FORCE_MAC_TOOLCHAIN": "",
-      "LANDMINES_VERBOSE": "1"
-    },
-    "name": "generate build files (gn)"
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-  {
-    "cmd": [
-      "RECIPE_PACKAGE_REPO[depot_tools]/ninja",
-      "-C",
-      "[START_DIR]/src/out/Debug-iphonesimulator",
-      "fake test"
-    ],
-    "cwd": "[START_DIR]/src/out/Debug-iphonesimulator",
-    "env": {
-      "FORCE_MAC_TOOLCHAIN": "",
-      "LANDMINES_VERBOSE": "1"
-    },
-    "name": "compile"
-  },
-  {
-    "cmd": [],
-    "cwd": "[START_DIR]/src",
-    "name": "bootstrap swarming"
-  },
-  {
-    "cmd": [
-      "python",
-      "-u",
-      "[START_DIR]/src/tools/swarming_client/swarming.py",
-      "--version"
-    ],
-    "cwd": "[START_DIR]/src",
-    "name": "bootstrap swarming.swarming.py --version",
-    "stdout": "/path/to/tmp/",
-    "~followup_annotations": [
-      "@@@STEP_NEST_LEVEL@1@@@",
-      "@@@STEP_TEXT@1.2.3@@@"
-    ]
-  },
-  {
-    "cmd": [],
-    "cwd": "[START_DIR]/src",
-    "name": "isolate"
-  },
-  {
-    "cmd": [
-      "python",
-      "-u",
-      "RECIPE_MODULE[recipe_engine::file]/resources/fileutil.py",
-      "--json-output",
-      "/path/to/tmp/json",
-      "copy",
-      "{'conditions': [['OS == \"ios\"', {'variables': {'files': ['<(app_path)/', 'src/ios/build/bots/scripts/', 'fake/file/path1/', 'fake/file/path2/', 'src/out/Debug-iphonesimulator/iossim'], 'command': ['src/ios/build/bots/scripts/run.py', '--app', '<(app_path)', '--args-json', '{\"test_args\": <(test_args),         \"xctest\": <(xctest),         \"test_cases\": <(test_cases),         \"restart\": <(restart)}', '--out-dir', '${ISOLATED_OUTDIR}', '--retries', '3', '--shards', '<(shards)', '--<(xcode_arg_name)', '<(xcode_version)', '--mac-toolchain-cmd', './mac_toolchain', '--xcode-path', 'Xcode.app', '--wpr-tools-path', '<(wpr_tools_path)', '--replay-path', '<(replay_path)', '--xcode-parallelization', '--iossim', 'src/out/Debug-iphonesimulator/iossim', '--platform', '<(platform)', '--version', '<(version)']}}]]}",
-      "[START_DIR]/template.isolate"
-    ],
-    "cwd": "[START_DIR]/src",
-    "infra_step": true,
-    "name": "isolate.generate template.isolate",
-    "~followup_annotations": [
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-      "@@@STEP_LOG_LINE@template.isolate@      \"OS == \\\"ios\\\"\", @@@",
-      "@@@STEP_LOG_LINE@template.isolate@      {@@@",
-      "@@@STEP_LOG_LINE@template.isolate@        \"variables\": {@@@",
-      "@@@STEP_LOG_LINE@template.isolate@          \"command\": [@@@",
-      "@@@STEP_LOG_LINE@template.isolate@            \"src/ios/build/bots/scripts/run.py\", @@@",
-      "@@@STEP_LOG_LINE@template.isolate@            \"--app\", @@@",
-      "@@@STEP_LOG_LINE@template.isolate@            \"<(app_path)\", @@@",
-      "@@@STEP_LOG_LINE@template.isolate@            \"--args-json\", @@@",
-      "@@@STEP_LOG_LINE@template.isolate@            \"{\\\"test_args\\\": <(test_args),         \\\"xctest\\\": <(xctest),         \\\"test_cases\\\": <(test_cases),         \\\"restart\\\": <(restart)}\", @@@",
-      "@@@STEP_LOG_LINE@template.isolate@            \"--out-dir\", @@@",
-      "@@@STEP_LOG_LINE@template.isolate@            \"${ISOLATED_OUTDIR}\", @@@",
-      "@@@STEP_LOG_LINE@template.isolate@            \"--retries\", @@@",
-      "@@@STEP_LOG_LINE@template.isolate@            \"3\", @@@",
-      "@@@STEP_LOG_LINE@template.isolate@            \"--shards\", @@@",
-      "@@@STEP_LOG_LINE@template.isolate@            \"<(shards)\", @@@",
-      "@@@STEP_LOG_LINE@template.isolate@            \"--<(xcode_arg_name)\", @@@",
-      "@@@STEP_LOG_LINE@template.isolate@            \"<(xcode_version)\", @@@",
-      "@@@STEP_LOG_LINE@template.isolate@            \"--mac-toolchain-cmd\", @@@",
-      "@@@STEP_LOG_LINE@template.isolate@            \"./mac_toolchain\", @@@",
-      "@@@STEP_LOG_LINE@template.isolate@            \"--xcode-path\", @@@",
-      "@@@STEP_LOG_LINE@template.isolate@            \"Xcode.app\", @@@",
-      "@@@STEP_LOG_LINE@template.isolate@            \"--wpr-tools-path\", @@@",
-      "@@@STEP_LOG_LINE@template.isolate@            \"<(wpr_tools_path)\", @@@",
-      "@@@STEP_LOG_LINE@template.isolate@            \"--replay-path\", @@@",
-      "@@@STEP_LOG_LINE@template.isolate@            \"<(replay_path)\", @@@",
-      "@@@STEP_LOG_LINE@template.isolate@            \"--xcode-parallelization\", @@@",
-      "@@@STEP_LOG_LINE@template.isolate@            \"--iossim\", @@@",
-      "@@@STEP_LOG_LINE@template.isolate@            \"src/out/Debug-iphonesimulator/iossim\", @@@",
-      "@@@STEP_LOG_LINE@template.isolate@            \"--platform\", @@@",
-      "@@@STEP_LOG_LINE@template.isolate@            \"<(platform)\", @@@",
-      "@@@STEP_LOG_LINE@template.isolate@            \"--version\", @@@",
-      "@@@STEP_LOG_LINE@template.isolate@            \"<(version)\"@@@",
-      "@@@STEP_LOG_LINE@template.isolate@          ], @@@",
-      "@@@STEP_LOG_LINE@template.isolate@          \"files\": [@@@",
-      "@@@STEP_LOG_LINE@template.isolate@            \"<(app_path)/\", @@@",
-      "@@@STEP_LOG_LINE@template.isolate@            \"src/ios/build/bots/scripts/\", @@@",
-      "@@@STEP_LOG_LINE@template.isolate@            \"fake/file/path1/\", @@@",
-      "@@@STEP_LOG_LINE@template.isolate@            \"fake/file/path2/\", @@@",
-      "@@@STEP_LOG_LINE@template.isolate@            \"src/out/Debug-iphonesimulator/iossim\"@@@",
-      "@@@STEP_LOG_LINE@template.isolate@          ]@@@",
-      "@@@STEP_LOG_LINE@template.isolate@        }@@@",
-      "@@@STEP_LOG_LINE@template.isolate@      }@@@",
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-      "@@@STEP_LOG_LINE@template.isolate@}@@@",
-      "@@@STEP_LOG_END@template.isolate@@@"
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-      "python",
-      "-u",
-      "RECIPE_MODULE[recipe_engine::file]/resources/fileutil.py",
-      "--json-output",
-      "/path/to/tmp/json",
-      "copy",
-      "{\n  \"args\": [\n    \"--config-variable\", \n    \"OS\", \n    \"ios\", \n    \"--config-variable\", \n    \"app_path\", \n    \"src/out/Debug-iphonesimulator/fake test.app\", \n    \"--config-variable\", \n    \"restart\", \n    \"false\", \n    \"--config-variable\", \n    \"shards\", \n    \"4\", \n    \"--config-variable\", \n    \"test_args\", \n    \"[]\", \n    \"--config-variable\", \n    \"test_cases\", \n    \"[]\", \n    \"--config-variable\", \n    \"xctest\", \n    \"false\", \n    \"--config-variable\", \n    \"use_trusted_cert\", \n    \"false\", \n    \"--isolate\", \n    \"[START_DIR]/template.isolate\", \n    \"--isolated\", \n    \"[CLEANUP]/isolate_tmp_1/0.isolated\", \n    \"--path-variable\", \n    \"app_path\", \n    \"src/out/Debug-iphonesimulator/fake test.app\", \n    \"--config-variable\", \n    \"wpr_tools_path\", \n    \"NO_PATH\", \n    \"--config-variable\", \n    \"replay_path\", \n    \"NO_PATH\", \n    \"--config-variable\", \n    \"xcode_arg_name\", \n    \"xcode-build-version\", \n    \"--config-variable\", \n    \"xcode_version\", \n    \"09a123\", \n    \"--config-variable\", \n    \"platform\", \n    \"fake device\", \n    \"--config-variable\", \n    \"version\", \n    \"12.0.1\"\n  ], \n  \"dir\": \"[START_DIR]\", \n  \"version\": 1\n}",
-      "[CLEANUP]/isolate_tmp_1/0.isolated.gen.json"
-    ],
-    "cwd": "[START_DIR]/src",
-    "infra_step": true,
-    "name": "isolate.generate 0.isolated.gen.json",
-    "~followup_annotations": [
-      "@@@STEP_NEST_LEVEL@1@@@",
-      "@@@STEP_TEXT@fake test (fake device iOS 12.0.1)@@@",
-      "@@@STEP_LOG_LINE@0.isolated.gen.json@{@@@",
-      "@@@STEP_LOG_LINE@0.isolated.gen.json@  \"args\": [@@@",
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-      "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"OS\", @@@",
-      "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"ios\", @@@",
-      "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"--config-variable\", @@@",
-      "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"app_path\", @@@",
-      "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"src/out/Debug-iphonesimulator/fake test.app\", @@@",
-      "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"--config-variable\", @@@",
-      "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"restart\", @@@",
-      "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"false\", @@@",
-      "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"--config-variable\", @@@",
-      "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"shards\", @@@",
-      "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"4\", @@@",
-      "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"--config-variable\", @@@",
-      "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"test_args\", @@@",
-      "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"[]\", @@@",
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-      "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"test_cases\", @@@",
-      "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"[]\", @@@",
-      "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"--config-variable\", @@@",
-      "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"xctest\", @@@",
-      "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"false\", @@@",
-      "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"--config-variable\", @@@",
-      "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"use_trusted_cert\", @@@",
-      "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"false\", @@@",
-      "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"--isolate\", @@@",
-      "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"[START_DIR]/template.isolate\", @@@",
-      "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"--isolated\", @@@",
-      "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"[CLEANUP]/isolate_tmp_1/0.isolated\", @@@",
-      "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"--path-variable\", @@@",
-      "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"app_path\", @@@",
-      "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"src/out/Debug-iphonesimulator/fake test.app\", @@@",
-      "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"--config-variable\", @@@",
-      "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"wpr_tools_path\", @@@",
-      "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"NO_PATH\", @@@",
-      "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"--config-variable\", @@@",
-      "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"replay_path\", @@@",
-      "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"NO_PATH\", @@@",
-      "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"--config-variable\", @@@",
-      "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"xcode_arg_name\", @@@",
-      "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"xcode-build-version\", @@@",
-      "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"--config-variable\", @@@",
-      "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"xcode_version\", @@@",
-      "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"09a123\", @@@",
-      "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"--config-variable\", @@@",
-      "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"platform\", @@@",
-      "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"fake device\", @@@",
-      "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"--config-variable\", @@@",
-      "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"version\", @@@",
-      "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"12.0.1\"@@@",
-      "@@@STEP_LOG_LINE@0.isolated.gen.json@  ], @@@",
-      "@@@STEP_LOG_LINE@0.isolated.gen.json@  \"dir\": \"[START_DIR]\", @@@",
-      "@@@STEP_LOG_LINE@0.isolated.gen.json@  \"version\": 1@@@",
-      "@@@STEP_LOG_LINE@0.isolated.gen.json@}@@@",
-      "@@@STEP_LOG_END@0.isolated.gen.json@@@"
-    ]
-  },
-  {
-    "cmd": [
-      "python",
-      "-u",
-      "RECIPE_MODULE[build::isolate]/resources/isolate.py",
-      "[START_DIR]/src/tools/swarming_client",
-      "batcharchive",
-      "--dump-json",
-      "/path/to/tmp/json",
-      "--isolate-server",
-      "https://isolateserver.appspot.com",
-      "--eventlog-endpoint",
-      "prod",
-      "--verbose",
-      "--blacklist",
-      "*.pyc",
-      "--blacklist",
-      "*.swp",
-      "--blacklist",
-      ".git",
-      "[CLEANUP]/isolate_tmp_1/0.isolated.gen.json"
-    ],
-    "cwd": "[START_DIR]/src",
-    "name": "isolate.isolate tests",
-    "~followup_annotations": [
-      "@@@STEP_NEST_LEVEL@1@@@",
-      "@@@STEP_LOG_LINE@json.output@{@@@",
-      "@@@STEP_LOG_LINE@json.output@  \"0\": \"[dummy hash for 0]\"@@@",
-      "@@@STEP_LOG_LINE@json.output@}@@@",
-      "@@@STEP_LOG_END@json.output@@@",
-      "@@@SET_BUILD_PROPERTY@swarm_hashes@{\"0\": \"[dummy hash for 0]\"}@@@"
-    ]
-  },
-  {
-    "cmd": [],
-    "cwd": "[START_DIR]/src",
-    "name": "trigger"
-  },
-  {
-    "cmd": [
-      "python",
-      "-u",
-      "[START_DIR]/src/tools/swarming_client/swarming.py",
-      "trigger",
-      "--swarming",
-      "https://chromium-swarm.appspot.com",
-      "--isolate-server",
-      "https://isolateserver.appspot.com",
-      "--priority",
-      "200",
-      "--shards",
-      "1",
-      "--task-name",
-      "fake test (fake device iOS 12.0.1)/Mac/[dummy has/ios/0",
-      "--dump-json",
-      "/path/to/tmp/json",
-      "--expiration",
-      "3600",
-      "--io-timeout",
-      "1200",
-      "--hard-timeout",
-      "3600",
-      "--dimension",
-      "os",
-      "Mac",
-      "--dimension",
-      "pool",
-      "Chrome",
-      "--named-cache",
-      "swarming_module_cache_vpython",
-      ".swarming_module_cache/vpython",
-      "--named-cache",
-      "xcode_ios_09a123",
-      "Xcode.app",
-      "--service-account",
-      "ios-isolated-tester@chops-service-accounts.iam.gserviceaccount.com",
-      "--tag",
-      "build_is_experimental:false",
-      "--tag",
-      "buildername:ios",
-      "--tag",
-      "buildnumber:0",
-      "--tag",
-      "data:[dummy hash for 0]",
-      "--tag",
-      "device_type:fake device",
-      "--tag",
-      "ios_version:12.0.1",
-      "--tag",
-      "master:chromium.fyi",
-      "--tag",
-      "name:fake",
-      "--tag",
-      "platform:simulator",
-      "--tag",
-      "slavename:fake-vm",
-      "--tag",
-      "spec_name:chromium.fyi:ios:fake test:simulator:fake device:12.0.1:09a123",
-      "--tag",
-      "stepname:fake test (fake device iOS 12.0.1)",
-      "--tag",
-      "test:fake test",
-      "--cipd-package",
-      ".:infra/tools/mac_toolchain/${platform}:git_revision:796d2b92cff93fc2059623ce0a66284373ceea0a",
-      "--cipd-package",
-      ".swarming_module:infra/python/cpython/${platform}:TEST_VERSION",
-      "--cipd-package",
-      ".swarming_module:infra/tools/luci/logdog/butler/${platform}:TEST_VERSION",
-      "--cipd-package",
-      ".swarming_module:infra/tools/luci/vpython-native/${platform}:TEST_VERSION",
-      "--cipd-package",
-      ".swarming_module:infra/tools/luci/vpython/${platform}:TEST_VERSION",
-      "--env-prefix",
-      "PATH",
-      ".swarming_module",
-      "--env-prefix",
-      "PATH",
-      ".swarming_module/bin",
-      "--env-prefix",
-      "VPYTHON_VIRTUALENV_ROOT",
-      ".swarming_module_cache/vpython",
-      "--isolated",
-      "[dummy hash for 0]"
-    ],
-    "cwd": "[START_DIR]/src",
-    "infra_step": true,
-    "name": "trigger.[trigger] fake test (fake device iOS 12.0.1)",
-    "~followup_annotations": [
-      "@@@STEP_NEST_LEVEL@1@@@",
-      "@@@STEP_TEXT@Run on OS: 'Mac'@@@",
-      "@@@STEP_LOG_LINE@json.output@{@@@",
-      "@@@STEP_LOG_LINE@json.output@  \"base_task_name\": \"fake test (fake device iOS 12.0.1)/Mac/[dummy has/ios/0\", @@@",
-      "@@@STEP_LOG_LINE@json.output@  \"tasks\": {@@@",
-      "@@@STEP_LOG_LINE@json.output@    \"fake test (fake device iOS 12.0.1)/Mac/[dummy has/ios/0\": {@@@",
-      "@@@STEP_LOG_LINE@json.output@      \"shard_index\": 0, @@@",
-      "@@@STEP_LOG_LINE@json.output@      \"task_id\": \"10000\", @@@",
-      "@@@STEP_LOG_LINE@json.output@      \"view_url\": \"https://chromium-swarm.appspot.com/user/task/10000\"@@@",
-      "@@@STEP_LOG_LINE@json.output@    }@@@",
-      "@@@STEP_LOG_LINE@json.output@  }@@@",
-      "@@@STEP_LOG_LINE@json.output@}@@@",
-      "@@@STEP_LOG_END@json.output@@@",
-      "@@@STEP_LINK@shard #0@https://chromium-swarm.appspot.com/user/task/10000@@@"
-    ]
-  },
-  {
-    "cmd": [],
-    "cwd": "[START_DIR]/src",
-    "name": "ensure swarming"
-  },
-  {
-    "cmd": [
-      "cipd",
-      "ensure",
-      "-root",
-      "[CACHE]/swarming_client",
-      "-ensure-file",
-      "infra/tools/luci/swarming/${platform} git_revision:25958d48e89e980e2a97daeddc977fb5e2e1fb8c",
-      "-json-output",
-      "/path/to/tmp/json"
-    ],
-    "cwd": "[START_DIR]/src",
-    "infra_step": true,
-    "name": "ensure swarming.ensure_installed",
-    "~followup_annotations": [
-      "@@@STEP_NEST_LEVEL@1@@@",
-      "@@@STEP_LOG_LINE@json.output@{@@@",
-      "@@@STEP_LOG_LINE@json.output@  \"result\": {@@@",
-      "@@@STEP_LOG_LINE@json.output@    \"\": [@@@",
-      "@@@STEP_LOG_LINE@json.output@      {@@@",
-      "@@@STEP_LOG_LINE@json.output@        \"instance_id\": \"resolved-instance_id-of-git_revision:259\", @@@",
-      "@@@STEP_LOG_LINE@json.output@        \"package\": \"infra/tools/luci/swarming/resolved-platform\"@@@",
-      "@@@STEP_LOG_LINE@json.output@      }@@@",
-      "@@@STEP_LOG_LINE@json.output@    ]@@@",
-      "@@@STEP_LOG_LINE@json.output@  }@@@",
-      "@@@STEP_LOG_LINE@json.output@}@@@",
-      "@@@STEP_LOG_END@json.output@@@"
-    ]
-  },
-  {
-    "cmd": [
-      "python",
-      "-u",
-      "RECIPE_PACKAGE_REPO[build]/scripts/tools/runit.py",
-      "--show-path",
-      "--with-third-party-lib",
-      "--",
-      "python",
-      "RECIPE_MODULE[build::swarming]/resources/collect_task.py",
-      "-o",
-      "/path/to/tmp/json",
-      "--task-output-dir",
-      "[CLEANUP]/0_tmp_2",
-      "--merge-script",
-      "RECIPE_MODULE[build::swarming]/resources/noop_merge.py",
-      "--merge-script-stdout-file",
-      "/path/to/tmp/merge_script_log",
-      "--merge-additional-args",
-      "[]",
-      "--use-go-client",
-      "--summary-json-file",
-      "/path/to/tmp/json",
-      "--",
-      "swarming",
-      "collect",
-      "-server",
-      "https://chromium-swarm.appspot.com",
-      "-worker",
-      "50",
-      "-task-summary-python",
-      "-task-output-stdout",
-      "json",
-      "-verbose",
-      "-requests-json",
-      "{\"tasks\": [{\"task_id\": \"10000\"}]}"
-    ],
-    "env_prefixes": {
-      "PATH": [
-        "[CACHE]/swarming_client"
-      ]
-    },
-    "name": "fake test (fake device iOS 12.0.1)",
-    "~followup_annotations": [
-      "@@@STEP_TEXT@Run on OS: 'Mac'<br>Pending time: 0:01:11<br>Shard duration: 0:01:00@@@",
-      "@@@STEP_LOG_LINE@json.output@{}@@@",
-      "@@@STEP_LOG_END@json.output@@@",
-      "@@@STEP_LOG_LINE@swarming.summary@{@@@",
-      "@@@STEP_LOG_LINE@swarming.summary@  \"shards\": [@@@",
-      "@@@STEP_LOG_LINE@swarming.summary@    {@@@",
-      "@@@STEP_LOG_LINE@swarming.summary@      \"abandoned_ts\": null, @@@",
-      "@@@STEP_LOG_LINE@swarming.summary@      \"bot_id\": \"vm30\", @@@",
-      "@@@STEP_LOG_LINE@swarming.summary@      \"completed_ts\": \"2014-09-25T01:43:11.123\", @@@",
-      "@@@STEP_LOG_LINE@swarming.summary@      \"created_ts\": \"2014-09-25T01:41:00.123\", @@@",
-      "@@@STEP_LOG_LINE@swarming.summary@      \"duration\": 31.5, @@@",
-      "@@@STEP_LOG_LINE@swarming.summary@      \"exit_code\": \"0\", @@@",
-      "@@@STEP_LOG_LINE@swarming.summary@      \"failure\": false, @@@",
-      "@@@STEP_LOG_LINE@swarming.summary@      \"internal_failure\": false, @@@",
-      "@@@STEP_LOG_LINE@swarming.summary@      \"modified_ts\": \"2014-09-25 01:42:00\", @@@",
-      "@@@STEP_LOG_LINE@swarming.summary@      \"name\": \"heartbeat-canary-2014-09-25_01:41:55-os=Windows\", @@@",
-      "@@@STEP_LOG_LINE@swarming.summary@      \"output\": \"Heart beat succeeded on win32.\\nFoo\", @@@",
-      "@@@STEP_LOG_LINE@swarming.summary@      \"outputs_ref\": {@@@",
-      "@@@STEP_LOG_LINE@swarming.summary@        \"isolated\": \"abc123\", @@@",
-      "@@@STEP_LOG_LINE@swarming.summary@        \"isolatedserver\": \"https://isolateserver.appspot.com\", @@@",
-      "@@@STEP_LOG_LINE@swarming.summary@        \"namespace\": \"default-gzip\"@@@",
-      "@@@STEP_LOG_LINE@swarming.summary@      }, @@@",
-      "@@@STEP_LOG_LINE@swarming.summary@      \"started_ts\": \"2014-09-25T01:42:11.123\", @@@",
-      "@@@STEP_LOG_LINE@swarming.summary@      \"state\": \"COMPLETED\", @@@",
-      "@@@STEP_LOG_LINE@swarming.summary@      \"task_id\": \"148aa78d7aa0000\"@@@",
-      "@@@STEP_LOG_LINE@swarming.summary@    }@@@",
-      "@@@STEP_LOG_LINE@swarming.summary@  ]@@@",
-      "@@@STEP_LOG_LINE@swarming.summary@}@@@",
-      "@@@STEP_LOG_END@swarming.summary@@@",
-      "@@@STEP_LOG_LINE@Merge script log@Successfully merged all data@@@",
-      "@@@STEP_LOG_END@Merge script log@@@",
-      "@@@STEP_LINK@shard #0 (31.5 sec)@https://chromium-swarm.appspot.com/user/task/10000@@@",
-      "@@@STEP_LINK@test data@https://isolateserver.appspot.com/browse?namespace=default-gzip&hash=abc123@@@"
-    ]
-  },
-  {
-    "cmd": [
-      "python",
-      "-u",
-      "import sys; sys.exit(0)"
-    ],
-    "cwd": "[START_DIR]/src",
-    "name": "Tests statistics",
-    "~followup_annotations": [
-      "@@@STEP_TEXT@<br/>Stats<br/>Total shards: 1<br/>Total runtime: 31s <br/>@@@",
-      "@@@STEP_LOG_LINE@detailed stats@Total shards: 1@@@",
-      "@@@STEP_LOG_LINE@detailed stats@Total runtime: 31s @@@",
-      "@@@STEP_LOG_LINE@detailed stats@Min/mean/max: 31s / 31s / 31s@@@",
-      "@@@STEP_LOG_END@detailed stats@@@"
-    ]
-  },
-  {
-    "jsonResult": null,
-    "name": "$result"
-  }
-]
\ No newline at end of file
diff --git a/scripts/slave/recipe_modules/ios/examples/full.expected/xparallel_run_skip.json b/scripts/slave/recipe_modules/ios/examples/full.expected/xparallel_run_and_skip.json
similarity index 69%
rename from scripts/slave/recipe_modules/ios/examples/full.expected/xparallel_run_skip.json
rename to scripts/slave/recipe_modules/ios/examples/full.expected/xparallel_run_and_skip.json
index 070e5aa..daae42e 100644
--- a/scripts/slave/recipe_modules/ios/examples/full.expected/xparallel_run_skip.json
+++ b/scripts/slave/recipe_modules/ios/examples/full.expected/xparallel_run_and_skip.json
@@ -179,17 +179,21 @@
       "@@@STEP_LOG_LINE@json.output@    \"is_debug=true\", @@@",
       "@@@STEP_LOG_LINE@json.output@    \"target_cpu=\\\"x86\\\"\"@@@",
       "@@@STEP_LOG_LINE@json.output@  ], @@@",
-      "@@@STEP_LOG_LINE@json.output@  \"retries\": \"0\", @@@",
       "@@@STEP_LOG_LINE@json.output@  \"tests\": [@@@",
       "@@@STEP_LOG_LINE@json.output@    {@@@",
       "@@@STEP_LOG_LINE@json.output@      \"app\": \"fake test\", @@@",
       "@@@STEP_LOG_LINE@json.output@      \"device type\": \"fake device\", @@@",
       "@@@STEP_LOG_LINE@json.output@      \"os\": \"12.0.1\", @@@",
-      "@@@STEP_LOG_LINE@json.output@      \"shards\": 3@@@",
+      "@@@STEP_LOG_LINE@json.output@      \"shards\": 3, @@@",
+      "@@@STEP_LOG_LINE@json.output@      \"xcode parallelization\": true@@@",
+      "@@@STEP_LOG_LINE@json.output@    }, @@@",
+      "@@@STEP_LOG_LINE@json.output@    {@@@",
+      "@@@STEP_LOG_LINE@json.output@      \"app\": \"fake test2\", @@@",
+      "@@@STEP_LOG_LINE@json.output@      \"device type\": \"fake device\", @@@",
+      "@@@STEP_LOG_LINE@json.output@      \"os\": \"12.0.1\"@@@",
       "@@@STEP_LOG_LINE@json.output@    }@@@",
       "@@@STEP_LOG_LINE@json.output@  ], @@@",
-      "@@@STEP_LOG_LINE@json.output@  \"xcode build version\": \"09a123\", @@@",
-      "@@@STEP_LOG_LINE@json.output@  \"xcode parallelization\": false@@@",
+      "@@@STEP_LOG_LINE@json.output@  \"xcode build version\": \"09a123\"@@@",
       "@@@STEP_LOG_LINE@json.output@}@@@",
       "@@@STEP_LOG_END@json.output@@@"
     ]
@@ -328,7 +332,8 @@
       "RECIPE_PACKAGE_REPO[depot_tools]/ninja",
       "-C",
       "[START_DIR]/src/out/Debug-iphonesimulator",
-      "fake test"
+      "fake test",
+      "fake test2"
     ],
     "cwd": "[START_DIR]/src/out/Debug-iphonesimulator",
     "env": {
@@ -370,7 +375,7 @@
       "--json-output",
       "/path/to/tmp/json",
       "copy",
-      "{'conditions': [['OS == \"ios\"', {'variables': {'files': ['<(app_path)/', 'src/ios/build/bots/scripts/', 'fake/file/path1/', 'fake/file/path2/', 'src/out/Debug-iphonesimulator/iossim'], 'command': ['src/ios/build/bots/scripts/run.py', '--app', '<(app_path)', '--args-json', '{\"test_args\": <(test_args),         \"xctest\": <(xctest),         \"test_cases\": <(test_cases),         \"restart\": <(restart)}', '--out-dir', '${ISOLATED_OUTDIR}', '--retries', '0', '--shards', '<(shards)', '--<(xcode_arg_name)', '<(xcode_version)', '--mac-toolchain-cmd', './mac_toolchain', '--xcode-path', 'Xcode.app', '--wpr-tools-path', '<(wpr_tools_path)', '--replay-path', '<(replay_path)', '--iossim', 'src/out/Debug-iphonesimulator/iossim', '--platform', '<(platform)', '--version', '<(version)']}}]]}",
+      "{'conditions': [['OS == \"ios\"', {'variables': {'files': ['<(app_path)/', 'src/ios/build/bots/scripts/', 'fake/file/path1/', 'fake/file/path2/', 'src/out/Debug-iphonesimulator/iossim'], 'command': ['src/ios/build/bots/scripts/run.py', '--app', '<(app_path)', '--args-json', '{\"test_args\": <(test_args),         \"xctest\": <(xctest),         \"test_cases\": <(test_cases),         \"restart\": <(restart),         \"xcode-parallelization\": <(xcode_parallelization)}', '--out-dir', '${ISOLATED_OUTDIR}', '--retries', '3', '--shards', '<(shards)', '--<(xcode_arg_name)', '<(xcode_version)', '--mac-toolchain-cmd', './mac_toolchain', '--xcode-path', 'Xcode.app', '--wpr-tools-path', '<(wpr_tools_path)', '--replay-path', '<(replay_path)', '--iossim', 'src/out/Debug-iphonesimulator/iossim', '--platform', '<(platform)', '--version', '<(version)']}}]]}",
       "[START_DIR]/template.isolate"
     ],
     "cwd": "[START_DIR]/src",
@@ -389,11 +394,11 @@
       "@@@STEP_LOG_LINE@template.isolate@            \"--app\", @@@",
       "@@@STEP_LOG_LINE@template.isolate@            \"<(app_path)\", @@@",
       "@@@STEP_LOG_LINE@template.isolate@            \"--args-json\", @@@",
-      "@@@STEP_LOG_LINE@template.isolate@            \"{\\\"test_args\\\": <(test_args),         \\\"xctest\\\": <(xctest),         \\\"test_cases\\\": <(test_cases),         \\\"restart\\\": <(restart)}\", @@@",
+      "@@@STEP_LOG_LINE@template.isolate@            \"{\\\"test_args\\\": <(test_args),         \\\"xctest\\\": <(xctest),         \\\"test_cases\\\": <(test_cases),         \\\"restart\\\": <(restart),         \\\"xcode-parallelization\\\": <(xcode_parallelization)}\", @@@",
       "@@@STEP_LOG_LINE@template.isolate@            \"--out-dir\", @@@",
       "@@@STEP_LOG_LINE@template.isolate@            \"${ISOLATED_OUTDIR}\", @@@",
       "@@@STEP_LOG_LINE@template.isolate@            \"--retries\", @@@",
-      "@@@STEP_LOG_LINE@template.isolate@            \"0\", @@@",
+      "@@@STEP_LOG_LINE@template.isolate@            \"3\", @@@",
       "@@@STEP_LOG_LINE@template.isolate@            \"--shards\", @@@",
       "@@@STEP_LOG_LINE@template.isolate@            \"<(shards)\", @@@",
       "@@@STEP_LOG_LINE@template.isolate@            \"--<(xcode_arg_name)\", @@@",
@@ -436,7 +441,7 @@
       "--json-output",
       "/path/to/tmp/json",
       "copy",
-      "{\n  \"args\": [\n    \"--config-variable\", \n    \"OS\", \n    \"ios\", \n    \"--config-variable\", \n    \"app_path\", \n    \"src/out/Debug-iphonesimulator/fake test.app\", \n    \"--config-variable\", \n    \"restart\", \n    \"false\", \n    \"--config-variable\", \n    \"shards\", \n    \"3\", \n    \"--config-variable\", \n    \"test_args\", \n    \"[]\", \n    \"--config-variable\", \n    \"test_cases\", \n    \"[]\", \n    \"--config-variable\", \n    \"xctest\", \n    \"false\", \n    \"--config-variable\", \n    \"use_trusted_cert\", \n    \"false\", \n    \"--isolate\", \n    \"[START_DIR]/template.isolate\", \n    \"--isolated\", \n    \"[CLEANUP]/isolate_tmp_1/0.isolated\", \n    \"--path-variable\", \n    \"app_path\", \n    \"src/out/Debug-iphonesimulator/fake test.app\", \n    \"--config-variable\", \n    \"wpr_tools_path\", \n    \"NO_PATH\", \n    \"--config-variable\", \n    \"replay_path\", \n    \"NO_PATH\", \n    \"--config-variable\", \n    \"xcode_arg_name\", \n    \"xcode-build-version\", \n    \"--config-variable\", \n    \"xcode_version\", \n    \"09a123\", \n    \"--config-variable\", \n    \"platform\", \n    \"fake device\", \n    \"--config-variable\", \n    \"version\", \n    \"12.0.1\"\n  ], \n  \"dir\": \"[START_DIR]\", \n  \"version\": 1\n}",
+      "{\n  \"args\": [\n    \"--config-variable\", \n    \"OS\", \n    \"ios\", \n    \"--config-variable\", \n    \"app_path\", \n    \"src/out/Debug-iphonesimulator/fake test.app\", \n    \"--config-variable\", \n    \"restart\", \n    \"false\", \n    \"--config-variable\", \n    \"shards\", \n    \"3\", \n    \"--config-variable\", \n    \"test_args\", \n    \"[]\", \n    \"--config-variable\", \n    \"xcode_parallelization\", \n    \"true\", \n    \"--config-variable\", \n    \"test_cases\", \n    \"[]\", \n    \"--config-variable\", \n    \"xctest\", \n    \"false\", \n    \"--config-variable\", \n    \"use_trusted_cert\", \n    \"false\", \n    \"--isolate\", \n    \"[START_DIR]/template.isolate\", \n    \"--isolated\", \n    \"[CLEANUP]/isolate_tmp_1/0.isolated\", \n    \"--path-variable\", \n    \"app_path\", \n    \"src/out/Debug-iphonesimulator/fake test.app\", \n    \"--config-variable\", \n    \"wpr_tools_path\", \n    \"NO_PATH\", \n    \"--config-variable\", \n    \"replay_path\", \n    \"NO_PATH\", \n    \"--config-variable\", \n    \"xcode_arg_name\", \n    \"xcode-build-version\", \n    \"--config-variable\", \n    \"xcode_version\", \n    \"09a123\", \n    \"--config-variable\", \n    \"platform\", \n    \"fake device\", \n    \"--config-variable\", \n    \"version\", \n    \"12.0.1\"\n  ], \n  \"dir\": \"[START_DIR]\", \n  \"version\": 1\n}",
       "[CLEANUP]/isolate_tmp_1/0.isolated.gen.json"
     ],
     "cwd": "[START_DIR]/src",
@@ -463,6 +468,9 @@
       "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"test_args\", @@@",
       "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"[]\", @@@",
       "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"--config-variable\", @@@",
+      "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"xcode_parallelization\", @@@",
+      "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"true\", @@@",
+      "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"--config-variable\", @@@",
       "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"test_cases\", @@@",
       "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"[]\", @@@",
       "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"--config-variable\", @@@",
@@ -507,6 +515,84 @@
     "cmd": [
       "python",
       "-u",
+      "RECIPE_MODULE[recipe_engine::file]/resources/fileutil.py",
+      "--json-output",
+      "/path/to/tmp/json",
+      "copy",
+      "{\n  \"args\": [\n    \"--config-variable\", \n    \"OS\", \n    \"ios\", \n    \"--config-variable\", \n    \"app_path\", \n    \"src/out/Debug-iphonesimulator/fake test2.app\", \n    \"--config-variable\", \n    \"restart\", \n    \"false\", \n    \"--config-variable\", \n    \"shards\", \n    \"1\", \n    \"--config-variable\", \n    \"test_args\", \n    \"[]\", \n    \"--config-variable\", \n    \"xcode_parallelization\", \n    \"false\", \n    \"--config-variable\", \n    \"test_cases\", \n    \"[]\", \n    \"--config-variable\", \n    \"xctest\", \n    \"false\", \n    \"--config-variable\", \n    \"use_trusted_cert\", \n    \"false\", \n    \"--isolate\", \n    \"[START_DIR]/template.isolate\", \n    \"--isolated\", \n    \"[CLEANUP]/isolate_tmp_1/1.isolated\", \n    \"--path-variable\", \n    \"app_path\", \n    \"src/out/Debug-iphonesimulator/fake test2.app\", \n    \"--config-variable\", \n    \"wpr_tools_path\", \n    \"NO_PATH\", \n    \"--config-variable\", \n    \"replay_path\", \n    \"NO_PATH\", \n    \"--config-variable\", \n    \"xcode_arg_name\", \n    \"xcode-build-version\", \n    \"--config-variable\", \n    \"xcode_version\", \n    \"09a123\", \n    \"--config-variable\", \n    \"platform\", \n    \"fake device\", \n    \"--config-variable\", \n    \"version\", \n    \"12.0.1\"\n  ], \n  \"dir\": \"[START_DIR]\", \n  \"version\": 1\n}",
+      "[CLEANUP]/isolate_tmp_1/1.isolated.gen.json"
+    ],
+    "cwd": "[START_DIR]/src",
+    "infra_step": true,
+    "name": "isolate.generate 1.isolated.gen.json",
+    "~followup_annotations": [
+      "@@@STEP_NEST_LEVEL@1@@@",
+      "@@@STEP_TEXT@fake test2 (fake device iOS 12.0.1)@@@",
+      "@@@STEP_LOG_LINE@1.isolated.gen.json@{@@@",
+      "@@@STEP_LOG_LINE@1.isolated.gen.json@  \"args\": [@@@",
+      "@@@STEP_LOG_LINE@1.isolated.gen.json@    \"--config-variable\", @@@",
+      "@@@STEP_LOG_LINE@1.isolated.gen.json@    \"OS\", @@@",
+      "@@@STEP_LOG_LINE@1.isolated.gen.json@    \"ios\", @@@",
+      "@@@STEP_LOG_LINE@1.isolated.gen.json@    \"--config-variable\", @@@",
+      "@@@STEP_LOG_LINE@1.isolated.gen.json@    \"app_path\", @@@",
+      "@@@STEP_LOG_LINE@1.isolated.gen.json@    \"src/out/Debug-iphonesimulator/fake test2.app\", @@@",
+      "@@@STEP_LOG_LINE@1.isolated.gen.json@    \"--config-variable\", @@@",
+      "@@@STEP_LOG_LINE@1.isolated.gen.json@    \"restart\", @@@",
+      "@@@STEP_LOG_LINE@1.isolated.gen.json@    \"false\", @@@",
+      "@@@STEP_LOG_LINE@1.isolated.gen.json@    \"--config-variable\", @@@",
+      "@@@STEP_LOG_LINE@1.isolated.gen.json@    \"shards\", @@@",
+      "@@@STEP_LOG_LINE@1.isolated.gen.json@    \"1\", @@@",
+      "@@@STEP_LOG_LINE@1.isolated.gen.json@    \"--config-variable\", @@@",
+      "@@@STEP_LOG_LINE@1.isolated.gen.json@    \"test_args\", @@@",
+      "@@@STEP_LOG_LINE@1.isolated.gen.json@    \"[]\", @@@",
+      "@@@STEP_LOG_LINE@1.isolated.gen.json@    \"--config-variable\", @@@",
+      "@@@STEP_LOG_LINE@1.isolated.gen.json@    \"xcode_parallelization\", @@@",
+      "@@@STEP_LOG_LINE@1.isolated.gen.json@    \"false\", @@@",
+      "@@@STEP_LOG_LINE@1.isolated.gen.json@    \"--config-variable\", @@@",
+      "@@@STEP_LOG_LINE@1.isolated.gen.json@    \"test_cases\", @@@",
+      "@@@STEP_LOG_LINE@1.isolated.gen.json@    \"[]\", @@@",
+      "@@@STEP_LOG_LINE@1.isolated.gen.json@    \"--config-variable\", @@@",
+      "@@@STEP_LOG_LINE@1.isolated.gen.json@    \"xctest\", @@@",
+      "@@@STEP_LOG_LINE@1.isolated.gen.json@    \"false\", @@@",
+      "@@@STEP_LOG_LINE@1.isolated.gen.json@    \"--config-variable\", @@@",
+      "@@@STEP_LOG_LINE@1.isolated.gen.json@    \"use_trusted_cert\", @@@",
+      "@@@STEP_LOG_LINE@1.isolated.gen.json@    \"false\", @@@",
+      "@@@STEP_LOG_LINE@1.isolated.gen.json@    \"--isolate\", @@@",
+      "@@@STEP_LOG_LINE@1.isolated.gen.json@    \"[START_DIR]/template.isolate\", @@@",
+      "@@@STEP_LOG_LINE@1.isolated.gen.json@    \"--isolated\", @@@",
+      "@@@STEP_LOG_LINE@1.isolated.gen.json@    \"[CLEANUP]/isolate_tmp_1/1.isolated\", @@@",
+      "@@@STEP_LOG_LINE@1.isolated.gen.json@    \"--path-variable\", @@@",
+      "@@@STEP_LOG_LINE@1.isolated.gen.json@    \"app_path\", @@@",
+      "@@@STEP_LOG_LINE@1.isolated.gen.json@    \"src/out/Debug-iphonesimulator/fake test2.app\", @@@",
+      "@@@STEP_LOG_LINE@1.isolated.gen.json@    \"--config-variable\", @@@",
+      "@@@STEP_LOG_LINE@1.isolated.gen.json@    \"wpr_tools_path\", @@@",
+      "@@@STEP_LOG_LINE@1.isolated.gen.json@    \"NO_PATH\", @@@",
+      "@@@STEP_LOG_LINE@1.isolated.gen.json@    \"--config-variable\", @@@",
+      "@@@STEP_LOG_LINE@1.isolated.gen.json@    \"replay_path\", @@@",
+      "@@@STEP_LOG_LINE@1.isolated.gen.json@    \"NO_PATH\", @@@",
+      "@@@STEP_LOG_LINE@1.isolated.gen.json@    \"--config-variable\", @@@",
+      "@@@STEP_LOG_LINE@1.isolated.gen.json@    \"xcode_arg_name\", @@@",
+      "@@@STEP_LOG_LINE@1.isolated.gen.json@    \"xcode-build-version\", @@@",
+      "@@@STEP_LOG_LINE@1.isolated.gen.json@    \"--config-variable\", @@@",
+      "@@@STEP_LOG_LINE@1.isolated.gen.json@    \"xcode_version\", @@@",
+      "@@@STEP_LOG_LINE@1.isolated.gen.json@    \"09a123\", @@@",
+      "@@@STEP_LOG_LINE@1.isolated.gen.json@    \"--config-variable\", @@@",
+      "@@@STEP_LOG_LINE@1.isolated.gen.json@    \"platform\", @@@",
+      "@@@STEP_LOG_LINE@1.isolated.gen.json@    \"fake device\", @@@",
+      "@@@STEP_LOG_LINE@1.isolated.gen.json@    \"--config-variable\", @@@",
+      "@@@STEP_LOG_LINE@1.isolated.gen.json@    \"version\", @@@",
+      "@@@STEP_LOG_LINE@1.isolated.gen.json@    \"12.0.1\"@@@",
+      "@@@STEP_LOG_LINE@1.isolated.gen.json@  ], @@@",
+      "@@@STEP_LOG_LINE@1.isolated.gen.json@  \"dir\": \"[START_DIR]\", @@@",
+      "@@@STEP_LOG_LINE@1.isolated.gen.json@  \"version\": 1@@@",
+      "@@@STEP_LOG_LINE@1.isolated.gen.json@}@@@",
+      "@@@STEP_LOG_END@1.isolated.gen.json@@@"
+    ]
+  },
+  {
+    "cmd": [
+      "python",
+      "-u",
       "RECIPE_MODULE[build::isolate]/resources/isolate.py",
       "[START_DIR]/src/tools/swarming_client",
       "batcharchive",
@@ -523,17 +609,19 @@
       "*.swp",
       "--blacklist",
       ".git",
-      "[CLEANUP]/isolate_tmp_1/0.isolated.gen.json"
+      "[CLEANUP]/isolate_tmp_1/0.isolated.gen.json",
+      "[CLEANUP]/isolate_tmp_1/1.isolated.gen.json"
     ],
     "cwd": "[START_DIR]/src",
     "name": "isolate.isolate tests",
     "~followup_annotations": [
       "@@@STEP_NEST_LEVEL@1@@@",
       "@@@STEP_LOG_LINE@json.output@{@@@",
-      "@@@STEP_LOG_LINE@json.output@  \"0\": \"[dummy hash for 0]\"@@@",
+      "@@@STEP_LOG_LINE@json.output@  \"0\": \"[dummy hash for 0]\", @@@",
+      "@@@STEP_LOG_LINE@json.output@  \"1\": \"[dummy hash for 1]\"@@@",
       "@@@STEP_LOG_LINE@json.output@}@@@",
       "@@@STEP_LOG_END@json.output@@@",
-      "@@@SET_BUILD_PROPERTY@swarm_hashes@{\"0\": \"[dummy hash for 0]\"}@@@"
+      "@@@SET_BUILD_PROPERTY@swarm_hashes@{\"0\": \"[dummy hash for 0]\", \"1\": \"[dummy hash for 1]\"}@@@"
     ]
   },
   {
@@ -648,6 +736,112 @@
     ]
   },
   {
+    "cmd": [
+      "python",
+      "-u",
+      "[START_DIR]/src/tools/swarming_client/swarming.py",
+      "trigger",
+      "--swarming",
+      "https://chromium-swarm.appspot.com",
+      "--isolate-server",
+      "https://isolateserver.appspot.com",
+      "--priority",
+      "200",
+      "--shards",
+      "1",
+      "--task-name",
+      "fake test2 (fake device iOS 12.0.1)/Mac/[dummy has/ios/0",
+      "--dump-json",
+      "/path/to/tmp/json",
+      "--expiration",
+      "3600",
+      "--io-timeout",
+      "1200",
+      "--hard-timeout",
+      "3600",
+      "--dimension",
+      "os",
+      "Mac",
+      "--dimension",
+      "pool",
+      "Chrome",
+      "--named-cache",
+      "swarming_module_cache_vpython",
+      ".swarming_module_cache/vpython",
+      "--named-cache",
+      "xcode_ios_09a123",
+      "Xcode.app",
+      "--service-account",
+      "ios-isolated-tester@chops-service-accounts.iam.gserviceaccount.com",
+      "--tag",
+      "build_is_experimental:false",
+      "--tag",
+      "buildername:ios",
+      "--tag",
+      "buildnumber:0",
+      "--tag",
+      "data:[dummy hash for 1]",
+      "--tag",
+      "device_type:fake device",
+      "--tag",
+      "ios_version:12.0.1",
+      "--tag",
+      "master:chromium.fyi",
+      "--tag",
+      "name:fake",
+      "--tag",
+      "platform:simulator",
+      "--tag",
+      "slavename:fake-vm",
+      "--tag",
+      "spec_name:chromium.fyi:ios:fake test2:simulator:fake device:12.0.1:09a123",
+      "--tag",
+      "stepname:fake test2 (fake device iOS 12.0.1)",
+      "--tag",
+      "test:fake test2",
+      "--cipd-package",
+      ".:infra/tools/mac_toolchain/${platform}:git_revision:796d2b92cff93fc2059623ce0a66284373ceea0a",
+      "--cipd-package",
+      ".swarming_module:infra/python/cpython/${platform}:TEST_VERSION",
+      "--cipd-package",
+      ".swarming_module:infra/tools/luci/logdog/butler/${platform}:TEST_VERSION",
+      "--cipd-package",
+      ".swarming_module:infra/tools/luci/vpython-native/${platform}:TEST_VERSION",
+      "--cipd-package",
+      ".swarming_module:infra/tools/luci/vpython/${platform}:TEST_VERSION",
+      "--env-prefix",
+      "PATH",
+      ".swarming_module",
+      "--env-prefix",
+      "PATH",
+      ".swarming_module/bin",
+      "--env-prefix",
+      "VPYTHON_VIRTUALENV_ROOT",
+      ".swarming_module_cache/vpython",
+      "--isolated",
+      "[dummy hash for 1]"
+    ],
+    "cwd": "[START_DIR]/src",
+    "infra_step": true,
+    "name": "trigger.[trigger] fake test2 (fake device iOS 12.0.1)",
+    "~followup_annotations": [
+      "@@@STEP_NEST_LEVEL@1@@@",
+      "@@@STEP_TEXT@Run on OS: 'Mac'@@@",
+      "@@@STEP_LOG_LINE@json.output@{@@@",
+      "@@@STEP_LOG_LINE@json.output@  \"base_task_name\": \"fake test2 (fake device iOS 12.0.1)/Mac/[dummy has/ios/0\", @@@",
+      "@@@STEP_LOG_LINE@json.output@  \"tasks\": {@@@",
+      "@@@STEP_LOG_LINE@json.output@    \"fake test2 (fake device iOS 12.0.1)/Mac/[dummy has/ios/0\": {@@@",
+      "@@@STEP_LOG_LINE@json.output@      \"shard_index\": 0, @@@",
+      "@@@STEP_LOG_LINE@json.output@      \"task_id\": \"110000\", @@@",
+      "@@@STEP_LOG_LINE@json.output@      \"view_url\": \"https://chromium-swarm.appspot.com/user/task/110000\"@@@",
+      "@@@STEP_LOG_LINE@json.output@    }@@@",
+      "@@@STEP_LOG_LINE@json.output@  }@@@",
+      "@@@STEP_LOG_LINE@json.output@}@@@",
+      "@@@STEP_LOG_END@json.output@@@",
+      "@@@STEP_LINK@shard #0@https://chromium-swarm.appspot.com/user/task/110000@@@"
+    ]
+  },
+  {
     "cmd": [],
     "cwd": "[START_DIR]/src",
     "name": "ensure swarming"
@@ -764,14 +958,93 @@
     "cmd": [
       "python",
       "-u",
+      "RECIPE_PACKAGE_REPO[build]/scripts/tools/runit.py",
+      "--show-path",
+      "--with-third-party-lib",
+      "--",
+      "python",
+      "RECIPE_MODULE[build::swarming]/resources/collect_task.py",
+      "-o",
+      "/path/to/tmp/json",
+      "--task-output-dir",
+      "[CLEANUP]/1_tmp_3",
+      "--merge-script",
+      "RECIPE_MODULE[build::swarming]/resources/noop_merge.py",
+      "--merge-script-stdout-file",
+      "/path/to/tmp/merge_script_log",
+      "--merge-additional-args",
+      "[]",
+      "--use-go-client",
+      "--summary-json-file",
+      "/path/to/tmp/json",
+      "--",
+      "swarming",
+      "collect",
+      "-server",
+      "https://chromium-swarm.appspot.com",
+      "-worker",
+      "50",
+      "-task-summary-python",
+      "-task-output-stdout",
+      "json",
+      "-verbose",
+      "-requests-json",
+      "{\"tasks\": [{\"task_id\": \"110000\"}]}"
+    ],
+    "env_prefixes": {
+      "PATH": [
+        "[CACHE]/swarming_client"
+      ]
+    },
+    "name": "fake test2 (fake device iOS 12.0.1)",
+    "~followup_annotations": [
+      "@@@STEP_TEXT@Run on OS: 'Mac'<br>Pending time: 0:01:11<br>Shard duration: 0:01:00@@@",
+      "@@@STEP_LOG_LINE@json.output@{}@@@",
+      "@@@STEP_LOG_END@json.output@@@",
+      "@@@STEP_LOG_LINE@swarming.summary@{@@@",
+      "@@@STEP_LOG_LINE@swarming.summary@  \"shards\": [@@@",
+      "@@@STEP_LOG_LINE@swarming.summary@    {@@@",
+      "@@@STEP_LOG_LINE@swarming.summary@      \"abandoned_ts\": null, @@@",
+      "@@@STEP_LOG_LINE@swarming.summary@      \"bot_id\": \"vm30\", @@@",
+      "@@@STEP_LOG_LINE@swarming.summary@      \"completed_ts\": \"2014-09-25T01:43:11.123\", @@@",
+      "@@@STEP_LOG_LINE@swarming.summary@      \"created_ts\": \"2014-09-25T01:41:00.123\", @@@",
+      "@@@STEP_LOG_LINE@swarming.summary@      \"duration\": 31.5, @@@",
+      "@@@STEP_LOG_LINE@swarming.summary@      \"exit_code\": \"0\", @@@",
+      "@@@STEP_LOG_LINE@swarming.summary@      \"failure\": false, @@@",
+      "@@@STEP_LOG_LINE@swarming.summary@      \"internal_failure\": false, @@@",
+      "@@@STEP_LOG_LINE@swarming.summary@      \"modified_ts\": \"2014-09-25 01:42:00\", @@@",
+      "@@@STEP_LOG_LINE@swarming.summary@      \"name\": \"heartbeat-canary-2014-09-25_01:41:55-os=Windows\", @@@",
+      "@@@STEP_LOG_LINE@swarming.summary@      \"output\": \"Heart beat succeeded on win32.\\nFoo\", @@@",
+      "@@@STEP_LOG_LINE@swarming.summary@      \"outputs_ref\": {@@@",
+      "@@@STEP_LOG_LINE@swarming.summary@        \"isolated\": \"abc123\", @@@",
+      "@@@STEP_LOG_LINE@swarming.summary@        \"isolatedserver\": \"https://isolateserver.appspot.com\", @@@",
+      "@@@STEP_LOG_LINE@swarming.summary@        \"namespace\": \"default-gzip\"@@@",
+      "@@@STEP_LOG_LINE@swarming.summary@      }, @@@",
+      "@@@STEP_LOG_LINE@swarming.summary@      \"started_ts\": \"2014-09-25T01:42:11.123\", @@@",
+      "@@@STEP_LOG_LINE@swarming.summary@      \"state\": \"COMPLETED\", @@@",
+      "@@@STEP_LOG_LINE@swarming.summary@      \"task_id\": \"148aa78d7aa0000\"@@@",
+      "@@@STEP_LOG_LINE@swarming.summary@    }@@@",
+      "@@@STEP_LOG_LINE@swarming.summary@  ]@@@",
+      "@@@STEP_LOG_LINE@swarming.summary@}@@@",
+      "@@@STEP_LOG_END@swarming.summary@@@",
+      "@@@STEP_LOG_LINE@Merge script log@Successfully merged all data@@@",
+      "@@@STEP_LOG_END@Merge script log@@@",
+      "@@@STEP_LINK@shard #0 (31.5 sec)@https://chromium-swarm.appspot.com/user/task/110000@@@",
+      "@@@STEP_LINK@test data@https://isolateserver.appspot.com/browse?namespace=default-gzip&hash=abc123@@@"
+    ]
+  },
+  {
+    "cmd": [
+      "python",
+      "-u",
       "import sys; sys.exit(0)"
     ],
     "cwd": "[START_DIR]/src",
     "name": "Tests statistics",
     "~followup_annotations": [
-      "@@@STEP_TEXT@<br/>Stats<br/>Total shards: 1<br/>Total runtime: 31s <br/>@@@",
-      "@@@STEP_LOG_LINE@detailed stats@Total shards: 1@@@",
-      "@@@STEP_LOG_LINE@detailed stats@Total runtime: 31s @@@",
+      "@@@STEP_TEXT@<br/>Stats<br/>Total shards: 2<br/>Total runtime: 0:01:03 <br/>@@@",
+      "@@@STEP_LOG_LINE@detailed stats@Total shards: 2@@@",
+      "@@@STEP_LOG_LINE@detailed stats@Total runtime: 0:01:03 @@@",
       "@@@STEP_LOG_LINE@detailed stats@Min/mean/max: 31s / 31s / 31s@@@",
       "@@@STEP_LOG_END@detailed stats@@@"
     ]
diff --git a/scripts/slave/recipe_modules/ios/examples/full.py b/scripts/slave/recipe_modules/ios/examples/full.py
index 5542b83..5ac16c4 100644
--- a/scripts/slave/recipe_modules/ios/examples/full.py
+++ b/scripts/slave/recipe_modules/ios/examples/full.py
@@ -865,7 +865,7 @@
   )
 
   yield (
-    api.test('xparallel_run')
+    api.test('xparallel_run_and_skip')
     + api.platform('mac', 64)
     + api.properties(
       buildername='ios',
@@ -883,50 +883,19 @@
         'is_debug=true',
         'target_cpu="x86"',
       ],
-      'xcode parallelization': True,
       'tests': [
         {
-          'shards': 4,
-          'app': 'fake test',
-          'device type': 'fake device',
-          'os': '12.0.1',
-        },
-      ],
-    })
-    + api.step_data(
-        'bootstrap swarming.swarming.py --version',
-        stdout=api.raw_io.output_text('1.2.3'),
-    )
-  )
-
-  yield (
-    api.test('xparallel_run_skip')
-    + api.platform('mac', 64)
-    + api.properties(
-      buildername='ios',
-      buildnumber='0',
-      mastername='chromium.fyi',
-      bot_id='fake-vm',
-    )
-    + api.ios.make_test_build_config({
-      'xcode build version': '09a123',
-      'additional files': [
-        'fake/file/path1/',
-        'fake/file/path2/',
-      ],
-      'gn_args': [
-        'is_debug=true',
-        'target_cpu="x86"',
-      ],
-      'retries': '0',
-      'xcode parallelization': False,
-      'tests': [
-        {
+          'xcode parallelization': True,
           'shards': 3,
           'app': 'fake test',
           'device type': 'fake device',
           'os': '12.0.1',
         },
+        {
+          'app': 'fake test2',
+          'device type': 'fake device',
+          'os': '12.0.1',
+        }
       ],
     })
     + api.step_data(
diff --git a/scripts/slave/recipes/ios/try.expected/additional_compile_targets.json b/scripts/slave/recipes/ios/try.expected/additional_compile_targets.json
index 495773e..4300f2e 100644
--- a/scripts/slave/recipes/ios/try.expected/additional_compile_targets.json
+++ b/scripts/slave/recipes/ios/try.expected/additional_compile_targets.json
@@ -529,7 +529,7 @@
       "--json-output",
       "/path/to/tmp/json",
       "copy",
-      "{'conditions': [['OS == \"ios\"', {'variables': {'files': ['<(app_path)/', 'src/ios/build/bots/scripts/', 'src/out/Debug-iphonesimulator/iossim'], 'command': ['src/ios/build/bots/scripts/run.py', '--app', '<(app_path)', '--args-json', '{\"test_args\": <(test_args),         \"xctest\": <(xctest),         \"test_cases\": <(test_cases),         \"restart\": <(restart)}', '--out-dir', '${ISOLATED_OUTDIR}', '--retries', '3', '--shards', '<(shards)', '--<(xcode_arg_name)', '<(xcode_version)', '--mac-toolchain-cmd', './mac_toolchain', '--xcode-path', 'Xcode.app', '--wpr-tools-path', '<(wpr_tools_path)', '--replay-path', '<(replay_path)', '--iossim', 'src/out/Debug-iphonesimulator/iossim', '--platform', '<(platform)', '--version', '<(version)']}}]]}",
+      "{'conditions': [['OS == \"ios\"', {'variables': {'files': ['<(app_path)/', 'src/ios/build/bots/scripts/', 'src/out/Debug-iphonesimulator/iossim'], 'command': ['src/ios/build/bots/scripts/run.py', '--app', '<(app_path)', '--args-json', '{\"test_args\": <(test_args),         \"xctest\": <(xctest),         \"test_cases\": <(test_cases),         \"restart\": <(restart),         \"xcode-parallelization\": <(xcode_parallelization)}', '--out-dir', '${ISOLATED_OUTDIR}', '--retries', '3', '--shards', '<(shards)', '--<(xcode_arg_name)', '<(xcode_version)', '--mac-toolchain-cmd', './mac_toolchain', '--xcode-path', 'Xcode.app', '--wpr-tools-path', '<(wpr_tools_path)', '--replay-path', '<(replay_path)', '--iossim', 'src/out/Debug-iphonesimulator/iossim', '--platform', '<(platform)', '--version', '<(version)']}}]]}",
       "[BUILDER_CACHE]/linux/template.isolate"
     ],
     "cwd": "[BUILDER_CACHE]/linux/src",
@@ -548,7 +548,7 @@
       "@@@STEP_LOG_LINE@template.isolate@            \"--app\", @@@",
       "@@@STEP_LOG_LINE@template.isolate@            \"<(app_path)\", @@@",
       "@@@STEP_LOG_LINE@template.isolate@            \"--args-json\", @@@",
-      "@@@STEP_LOG_LINE@template.isolate@            \"{\\\"test_args\\\": <(test_args),         \\\"xctest\\\": <(xctest),         \\\"test_cases\\\": <(test_cases),         \\\"restart\\\": <(restart)}\", @@@",
+      "@@@STEP_LOG_LINE@template.isolate@            \"{\\\"test_args\\\": <(test_args),         \\\"xctest\\\": <(xctest),         \\\"test_cases\\\": <(test_cases),         \\\"restart\\\": <(restart),         \\\"xcode-parallelization\\\": <(xcode_parallelization)}\", @@@",
       "@@@STEP_LOG_LINE@template.isolate@            \"--out-dir\", @@@",
       "@@@STEP_LOG_LINE@template.isolate@            \"${ISOLATED_OUTDIR}\", @@@",
       "@@@STEP_LOG_LINE@template.isolate@            \"--retries\", @@@",
diff --git a/scripts/slave/recipes/ios/try.expected/basic.json b/scripts/slave/recipes/ios/try.expected/basic.json
index 1df2220..d6f9390 100644
--- a/scripts/slave/recipes/ios/try.expected/basic.json
+++ b/scripts/slave/recipes/ios/try.expected/basic.json
@@ -535,7 +535,7 @@
       "--json-output",
       "/path/to/tmp/json",
       "copy",
-      "{'conditions': [['OS == \"ios\"', {'variables': {'files': ['<(app_path)/', 'src/ios/build/bots/scripts/', 'src/out/Debug-iphonesimulator/iossim'], 'command': ['src/ios/build/bots/scripts/run.py', '--app', '<(app_path)', '--args-json', '{\"test_args\": <(test_args),         \"xctest\": <(xctest),         \"test_cases\": <(test_cases),         \"restart\": <(restart)}', '--out-dir', '${ISOLATED_OUTDIR}', '--retries', '3', '--shards', '<(shards)', '--<(xcode_arg_name)', '<(xcode_version)', '--mac-toolchain-cmd', './mac_toolchain', '--xcode-path', 'Xcode.app', '--wpr-tools-path', '<(wpr_tools_path)', '--replay-path', '<(replay_path)', '--iossim', 'src/out/Debug-iphonesimulator/iossim', '--platform', '<(platform)', '--version', '<(version)']}}]]}",
+      "{'conditions': [['OS == \"ios\"', {'variables': {'files': ['<(app_path)/', 'src/ios/build/bots/scripts/', 'src/out/Debug-iphonesimulator/iossim'], 'command': ['src/ios/build/bots/scripts/run.py', '--app', '<(app_path)', '--args-json', '{\"test_args\": <(test_args),         \"xctest\": <(xctest),         \"test_cases\": <(test_cases),         \"restart\": <(restart),         \"xcode-parallelization\": <(xcode_parallelization)}', '--out-dir', '${ISOLATED_OUTDIR}', '--retries', '3', '--shards', '<(shards)', '--<(xcode_arg_name)', '<(xcode_version)', '--mac-toolchain-cmd', './mac_toolchain', '--xcode-path', 'Xcode.app', '--wpr-tools-path', '<(wpr_tools_path)', '--replay-path', '<(replay_path)', '--iossim', 'src/out/Debug-iphonesimulator/iossim', '--platform', '<(platform)', '--version', '<(version)']}}]]}",
       "[BUILDER_CACHE]/linux/template.isolate"
     ],
     "cwd": "[BUILDER_CACHE]/linux/src",
@@ -554,7 +554,7 @@
       "@@@STEP_LOG_LINE@template.isolate@            \"--app\", @@@",
       "@@@STEP_LOG_LINE@template.isolate@            \"<(app_path)\", @@@",
       "@@@STEP_LOG_LINE@template.isolate@            \"--args-json\", @@@",
-      "@@@STEP_LOG_LINE@template.isolate@            \"{\\\"test_args\\\": <(test_args),         \\\"xctest\\\": <(xctest),         \\\"test_cases\\\": <(test_cases),         \\\"restart\\\": <(restart)}\", @@@",
+      "@@@STEP_LOG_LINE@template.isolate@            \"{\\\"test_args\\\": <(test_args),         \\\"xctest\\\": <(xctest),         \\\"test_cases\\\": <(test_cases),         \\\"restart\\\": <(restart),         \\\"xcode-parallelization\\\": <(xcode_parallelization)}\", @@@",
       "@@@STEP_LOG_LINE@template.isolate@            \"--out-dir\", @@@",
       "@@@STEP_LOG_LINE@template.isolate@            \"${ISOLATED_OUTDIR}\", @@@",
       "@@@STEP_LOG_LINE@template.isolate@            \"--retries\", @@@",
@@ -599,7 +599,7 @@
       "--json-output",
       "/path/to/tmp/json",
       "copy",
-      "{\n  \"args\": [\n    \"--config-variable\", \n    \"OS\", \n    \"ios\", \n    \"--config-variable\", \n    \"app_path\", \n    \"src/out/Debug-iphonesimulator/fake tests.app\", \n    \"--config-variable\", \n    \"restart\", \n    \"false\", \n    \"--config-variable\", \n    \"shards\", \n    \"1\", \n    \"--config-variable\", \n    \"test_args\", \n    \"[]\", \n    \"--config-variable\", \n    \"test_cases\", \n    \"[]\", \n    \"--config-variable\", \n    \"xctest\", \n    \"true\", \n    \"--config-variable\", \n    \"use_trusted_cert\", \n    \"false\", \n    \"--isolate\", \n    \"[BUILDER_CACHE]/linux/template.isolate\", \n    \"--isolated\", \n    \"[CLEANUP]/isolate_tmp_1/0.isolated\", \n    \"--path-variable\", \n    \"app_path\", \n    \"src/out/Debug-iphonesimulator/fake tests.app\", \n    \"--config-variable\", \n    \"wpr_tools_path\", \n    \"NO_PATH\", \n    \"--config-variable\", \n    \"replay_path\", \n    \"NO_PATH\", \n    \"--config-variable\", \n    \"xcode_arg_name\", \n    \"xcode-build-version\", \n    \"--config-variable\", \n    \"xcode_version\", \n    \"9c40b\", \n    \"--config-variable\", \n    \"platform\", \n    \"fake device\", \n    \"--config-variable\", \n    \"version\", \n    \"8.1\"\n  ], \n  \"dir\": \"[BUILDER_CACHE]/linux\", \n  \"version\": 1\n}",
+      "{\n  \"args\": [\n    \"--config-variable\", \n    \"OS\", \n    \"ios\", \n    \"--config-variable\", \n    \"app_path\", \n    \"src/out/Debug-iphonesimulator/fake tests.app\", \n    \"--config-variable\", \n    \"restart\", \n    \"false\", \n    \"--config-variable\", \n    \"shards\", \n    \"1\", \n    \"--config-variable\", \n    \"test_args\", \n    \"[]\", \n    \"--config-variable\", \n    \"xcode_parallelization\", \n    \"false\", \n    \"--config-variable\", \n    \"test_cases\", \n    \"[]\", \n    \"--config-variable\", \n    \"xctest\", \n    \"true\", \n    \"--config-variable\", \n    \"use_trusted_cert\", \n    \"false\", \n    \"--isolate\", \n    \"[BUILDER_CACHE]/linux/template.isolate\", \n    \"--isolated\", \n    \"[CLEANUP]/isolate_tmp_1/0.isolated\", \n    \"--path-variable\", \n    \"app_path\", \n    \"src/out/Debug-iphonesimulator/fake tests.app\", \n    \"--config-variable\", \n    \"wpr_tools_path\", \n    \"NO_PATH\", \n    \"--config-variable\", \n    \"replay_path\", \n    \"NO_PATH\", \n    \"--config-variable\", \n    \"xcode_arg_name\", \n    \"xcode-build-version\", \n    \"--config-variable\", \n    \"xcode_version\", \n    \"9c40b\", \n    \"--config-variable\", \n    \"platform\", \n    \"fake device\", \n    \"--config-variable\", \n    \"version\", \n    \"8.1\"\n  ], \n  \"dir\": \"[BUILDER_CACHE]/linux\", \n  \"version\": 1\n}",
       "[CLEANUP]/isolate_tmp_1/0.isolated.gen.json"
     ],
     "cwd": "[BUILDER_CACHE]/linux/src",
@@ -626,6 +626,9 @@
       "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"test_args\", @@@",
       "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"[]\", @@@",
       "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"--config-variable\", @@@",
+      "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"xcode_parallelization\", @@@",
+      "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"false\", @@@",
+      "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"--config-variable\", @@@",
       "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"test_cases\", @@@",
       "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"[]\", @@@",
       "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"--config-variable\", @@@",
diff --git a/scripts/slave/recipes/ios/try.expected/gn.json b/scripts/slave/recipes/ios/try.expected/gn.json
index 7d8492e..6a2b4fe 100644
--- a/scripts/slave/recipes/ios/try.expected/gn.json
+++ b/scripts/slave/recipes/ios/try.expected/gn.json
@@ -804,7 +804,7 @@
       "--json-output",
       "/path/to/tmp/json",
       "copy",
-      "{'conditions': [['OS == \"ios\"', {'variables': {'files': ['<(app_path)/', 'src/ios/build/bots/scripts/', 'src/out/Debug-iphonesimulator/iossim'], 'command': ['src/ios/build/bots/scripts/run.py', '--app', '<(app_path)', '--args-json', '{\"test_args\": <(test_args),         \"xctest\": <(xctest),         \"test_cases\": <(test_cases),         \"restart\": <(restart)}', '--out-dir', '${ISOLATED_OUTDIR}', '--retries', '3', '--shards', '<(shards)', '--<(xcode_arg_name)', '<(xcode_version)', '--mac-toolchain-cmd', './mac_toolchain', '--xcode-path', 'Xcode.app', '--wpr-tools-path', '<(wpr_tools_path)', '--replay-path', '<(replay_path)', '--iossim', 'src/out/Debug-iphonesimulator/iossim', '--platform', '<(platform)', '--version', '<(version)']}}]]}",
+      "{'conditions': [['OS == \"ios\"', {'variables': {'files': ['<(app_path)/', 'src/ios/build/bots/scripts/', 'src/out/Debug-iphonesimulator/iossim'], 'command': ['src/ios/build/bots/scripts/run.py', '--app', '<(app_path)', '--args-json', '{\"test_args\": <(test_args),         \"xctest\": <(xctest),         \"test_cases\": <(test_cases),         \"restart\": <(restart),         \"xcode-parallelization\": <(xcode_parallelization)}', '--out-dir', '${ISOLATED_OUTDIR}', '--retries', '3', '--shards', '<(shards)', '--<(xcode_arg_name)', '<(xcode_version)', '--mac-toolchain-cmd', './mac_toolchain', '--xcode-path', 'Xcode.app', '--wpr-tools-path', '<(wpr_tools_path)', '--replay-path', '<(replay_path)', '--iossim', 'src/out/Debug-iphonesimulator/iossim', '--platform', '<(platform)', '--version', '<(version)']}}]]}",
       "[BUILDER_CACHE]/linux/template.isolate"
     ],
     "cwd": "[BUILDER_CACHE]/linux/src",
@@ -823,7 +823,7 @@
       "@@@STEP_LOG_LINE@template.isolate@            \"--app\", @@@",
       "@@@STEP_LOG_LINE@template.isolate@            \"<(app_path)\", @@@",
       "@@@STEP_LOG_LINE@template.isolate@            \"--args-json\", @@@",
-      "@@@STEP_LOG_LINE@template.isolate@            \"{\\\"test_args\\\": <(test_args),         \\\"xctest\\\": <(xctest),         \\\"test_cases\\\": <(test_cases),         \\\"restart\\\": <(restart)}\", @@@",
+      "@@@STEP_LOG_LINE@template.isolate@            \"{\\\"test_args\\\": <(test_args),         \\\"xctest\\\": <(xctest),         \\\"test_cases\\\": <(test_cases),         \\\"restart\\\": <(restart),         \\\"xcode-parallelization\\\": <(xcode_parallelization)}\", @@@",
       "@@@STEP_LOG_LINE@template.isolate@            \"--out-dir\", @@@",
       "@@@STEP_LOG_LINE@template.isolate@            \"${ISOLATED_OUTDIR}\", @@@",
       "@@@STEP_LOG_LINE@template.isolate@            \"--retries\", @@@",
@@ -868,7 +868,7 @@
       "--json-output",
       "/path/to/tmp/json",
       "copy",
-      "{\n  \"args\": [\n    \"--config-variable\", \n    \"OS\", \n    \"ios\", \n    \"--config-variable\", \n    \"app_path\", \n    \"src/out/Debug-iphonesimulator/fake tests.app\", \n    \"--config-variable\", \n    \"restart\", \n    \"false\", \n    \"--config-variable\", \n    \"shards\", \n    \"1\", \n    \"--config-variable\", \n    \"test_args\", \n    \"[]\", \n    \"--config-variable\", \n    \"test_cases\", \n    \"[]\", \n    \"--config-variable\", \n    \"xctest\", \n    \"false\", \n    \"--config-variable\", \n    \"use_trusted_cert\", \n    \"false\", \n    \"--isolate\", \n    \"[BUILDER_CACHE]/linux/template.isolate\", \n    \"--isolated\", \n    \"[CLEANUP]/isolate_tmp_1/0.isolated\", \n    \"--path-variable\", \n    \"app_path\", \n    \"src/out/Debug-iphonesimulator/fake tests.app\", \n    \"--config-variable\", \n    \"wpr_tools_path\", \n    \"NO_PATH\", \n    \"--config-variable\", \n    \"replay_path\", \n    \"NO_PATH\", \n    \"--config-variable\", \n    \"xcode_arg_name\", \n    \"xcode-build-version\", \n    \"--config-variable\", \n    \"xcode_version\", \n    \"9c40b\", \n    \"--config-variable\", \n    \"platform\", \n    \"fake device\", \n    \"--config-variable\", \n    \"version\", \n    \"8.1\"\n  ], \n  \"dir\": \"[BUILDER_CACHE]/linux\", \n  \"version\": 1\n}",
+      "{\n  \"args\": [\n    \"--config-variable\", \n    \"OS\", \n    \"ios\", \n    \"--config-variable\", \n    \"app_path\", \n    \"src/out/Debug-iphonesimulator/fake tests.app\", \n    \"--config-variable\", \n    \"restart\", \n    \"false\", \n    \"--config-variable\", \n    \"shards\", \n    \"1\", \n    \"--config-variable\", \n    \"test_args\", \n    \"[]\", \n    \"--config-variable\", \n    \"xcode_parallelization\", \n    \"false\", \n    \"--config-variable\", \n    \"test_cases\", \n    \"[]\", \n    \"--config-variable\", \n    \"xctest\", \n    \"false\", \n    \"--config-variable\", \n    \"use_trusted_cert\", \n    \"false\", \n    \"--isolate\", \n    \"[BUILDER_CACHE]/linux/template.isolate\", \n    \"--isolated\", \n    \"[CLEANUP]/isolate_tmp_1/0.isolated\", \n    \"--path-variable\", \n    \"app_path\", \n    \"src/out/Debug-iphonesimulator/fake tests.app\", \n    \"--config-variable\", \n    \"wpr_tools_path\", \n    \"NO_PATH\", \n    \"--config-variable\", \n    \"replay_path\", \n    \"NO_PATH\", \n    \"--config-variable\", \n    \"xcode_arg_name\", \n    \"xcode-build-version\", \n    \"--config-variable\", \n    \"xcode_version\", \n    \"9c40b\", \n    \"--config-variable\", \n    \"platform\", \n    \"fake device\", \n    \"--config-variable\", \n    \"version\", \n    \"8.1\"\n  ], \n  \"dir\": \"[BUILDER_CACHE]/linux\", \n  \"version\": 1\n}",
       "[CLEANUP]/isolate_tmp_1/0.isolated.gen.json"
     ],
     "cwd": "[BUILDER_CACHE]/linux/src",
@@ -895,6 +895,9 @@
       "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"test_args\", @@@",
       "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"[]\", @@@",
       "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"--config-variable\", @@@",
+      "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"xcode_parallelization\", @@@",
+      "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"false\", @@@",
+      "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"--config-variable\", @@@",
       "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"test_cases\", @@@",
       "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"[]\", @@@",
       "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"--config-variable\", @@@",
diff --git a/scripts/slave/recipes/ios/try.expected/icu_patch.json b/scripts/slave/recipes/ios/try.expected/icu_patch.json
index 439fcf1..d5844ae 100644
--- a/scripts/slave/recipes/ios/try.expected/icu_patch.json
+++ b/scripts/slave/recipes/ios/try.expected/icu_patch.json
@@ -505,7 +505,7 @@
       "--json-output",
       "/path/to/tmp/json",
       "copy",
-      "{'conditions': [['OS == \"ios\"', {'variables': {'files': ['<(app_path)/', 'src/ios/build/bots/scripts/', 'src/out/Debug-iphonesimulator/iossim'], 'command': ['src/ios/build/bots/scripts/run.py', '--app', '<(app_path)', '--args-json', '{\"test_args\": <(test_args),         \"xctest\": <(xctest),         \"test_cases\": <(test_cases),         \"restart\": <(restart)}', '--out-dir', '${ISOLATED_OUTDIR}', '--retries', '3', '--shards', '<(shards)', '--<(xcode_arg_name)', '<(xcode_version)', '--mac-toolchain-cmd', './mac_toolchain', '--xcode-path', 'Xcode.app', '--wpr-tools-path', '<(wpr_tools_path)', '--replay-path', '<(replay_path)', '--iossim', 'src/out/Debug-iphonesimulator/iossim', '--platform', '<(platform)', '--version', '<(version)']}}]]}",
+      "{'conditions': [['OS == \"ios\"', {'variables': {'files': ['<(app_path)/', 'src/ios/build/bots/scripts/', 'src/out/Debug-iphonesimulator/iossim'], 'command': ['src/ios/build/bots/scripts/run.py', '--app', '<(app_path)', '--args-json', '{\"test_args\": <(test_args),         \"xctest\": <(xctest),         \"test_cases\": <(test_cases),         \"restart\": <(restart),         \"xcode-parallelization\": <(xcode_parallelization)}', '--out-dir', '${ISOLATED_OUTDIR}', '--retries', '3', '--shards', '<(shards)', '--<(xcode_arg_name)', '<(xcode_version)', '--mac-toolchain-cmd', './mac_toolchain', '--xcode-path', 'Xcode.app', '--wpr-tools-path', '<(wpr_tools_path)', '--replay-path', '<(replay_path)', '--iossim', 'src/out/Debug-iphonesimulator/iossim', '--platform', '<(platform)', '--version', '<(version)']}}]]}",
       "[BUILDER_CACHE]/linux/template.isolate"
     ],
     "cwd": "[BUILDER_CACHE]/linux/src",
@@ -524,7 +524,7 @@
       "@@@STEP_LOG_LINE@template.isolate@            \"--app\", @@@",
       "@@@STEP_LOG_LINE@template.isolate@            \"<(app_path)\", @@@",
       "@@@STEP_LOG_LINE@template.isolate@            \"--args-json\", @@@",
-      "@@@STEP_LOG_LINE@template.isolate@            \"{\\\"test_args\\\": <(test_args),         \\\"xctest\\\": <(xctest),         \\\"test_cases\\\": <(test_cases),         \\\"restart\\\": <(restart)}\", @@@",
+      "@@@STEP_LOG_LINE@template.isolate@            \"{\\\"test_args\\\": <(test_args),         \\\"xctest\\\": <(xctest),         \\\"test_cases\\\": <(test_cases),         \\\"restart\\\": <(restart),         \\\"xcode-parallelization\\\": <(xcode_parallelization)}\", @@@",
       "@@@STEP_LOG_LINE@template.isolate@            \"--out-dir\", @@@",
       "@@@STEP_LOG_LINE@template.isolate@            \"${ISOLATED_OUTDIR}\", @@@",
       "@@@STEP_LOG_LINE@template.isolate@            \"--retries\", @@@",
diff --git a/scripts/slave/recipes/ios/try.expected/no_compilation.json b/scripts/slave/recipes/ios/try.expected/no_compilation.json
index 8d804d9..c09b873 100644
--- a/scripts/slave/recipes/ios/try.expected/no_compilation.json
+++ b/scripts/slave/recipes/ios/try.expected/no_compilation.json
@@ -501,7 +501,7 @@
       "--json-output",
       "/path/to/tmp/json",
       "copy",
-      "{'conditions': [['OS == \"ios\"', {'variables': {'files': ['<(app_path)/', 'src/ios/build/bots/scripts/', 'src/out/Debug-iphonesimulator/iossim'], 'command': ['src/ios/build/bots/scripts/run.py', '--app', '<(app_path)', '--args-json', '{\"test_args\": <(test_args),         \"xctest\": <(xctest),         \"test_cases\": <(test_cases),         \"restart\": <(restart)}', '--out-dir', '${ISOLATED_OUTDIR}', '--retries', '3', '--shards', '<(shards)', '--<(xcode_arg_name)', '<(xcode_version)', '--mac-toolchain-cmd', './mac_toolchain', '--xcode-path', 'Xcode.app', '--wpr-tools-path', '<(wpr_tools_path)', '--replay-path', '<(replay_path)', '--iossim', 'src/out/Debug-iphonesimulator/iossim', '--platform', '<(platform)', '--version', '<(version)']}}]]}",
+      "{'conditions': [['OS == \"ios\"', {'variables': {'files': ['<(app_path)/', 'src/ios/build/bots/scripts/', 'src/out/Debug-iphonesimulator/iossim'], 'command': ['src/ios/build/bots/scripts/run.py', '--app', '<(app_path)', '--args-json', '{\"test_args\": <(test_args),         \"xctest\": <(xctest),         \"test_cases\": <(test_cases),         \"restart\": <(restart),         \"xcode-parallelization\": <(xcode_parallelization)}', '--out-dir', '${ISOLATED_OUTDIR}', '--retries', '3', '--shards', '<(shards)', '--<(xcode_arg_name)', '<(xcode_version)', '--mac-toolchain-cmd', './mac_toolchain', '--xcode-path', 'Xcode.app', '--wpr-tools-path', '<(wpr_tools_path)', '--replay-path', '<(replay_path)', '--iossim', 'src/out/Debug-iphonesimulator/iossim', '--platform', '<(platform)', '--version', '<(version)']}}]]}",
       "[BUILDER_CACHE]/linux/template.isolate"
     ],
     "cwd": "[BUILDER_CACHE]/linux/src",
@@ -520,7 +520,7 @@
       "@@@STEP_LOG_LINE@template.isolate@            \"--app\", @@@",
       "@@@STEP_LOG_LINE@template.isolate@            \"<(app_path)\", @@@",
       "@@@STEP_LOG_LINE@template.isolate@            \"--args-json\", @@@",
-      "@@@STEP_LOG_LINE@template.isolate@            \"{\\\"test_args\\\": <(test_args),         \\\"xctest\\\": <(xctest),         \\\"test_cases\\\": <(test_cases),         \\\"restart\\\": <(restart)}\", @@@",
+      "@@@STEP_LOG_LINE@template.isolate@            \"{\\\"test_args\\\": <(test_args),         \\\"xctest\\\": <(xctest),         \\\"test_cases\\\": <(test_cases),         \\\"restart\\\": <(restart),         \\\"xcode-parallelization\\\": <(xcode_parallelization)}\", @@@",
       "@@@STEP_LOG_LINE@template.isolate@            \"--out-dir\", @@@",
       "@@@STEP_LOG_LINE@template.isolate@            \"${ISOLATED_OUTDIR}\", @@@",
       "@@@STEP_LOG_LINE@template.isolate@            \"--retries\", @@@",
diff --git a/scripts/slave/recipes/ios/try.expected/no_tests.json b/scripts/slave/recipes/ios/try.expected/no_tests.json
index 199a0b0..2f754db 100644
--- a/scripts/slave/recipes/ios/try.expected/no_tests.json
+++ b/scripts/slave/recipes/ios/try.expected/no_tests.json
@@ -506,7 +506,7 @@
       "--json-output",
       "/path/to/tmp/json",
       "copy",
-      "{'conditions': [['OS == \"ios\"', {'variables': {'files': ['<(app_path)/', 'src/ios/build/bots/scripts/', 'src/out/Debug-iphonesimulator/iossim'], 'command': ['src/ios/build/bots/scripts/run.py', '--app', '<(app_path)', '--args-json', '{\"test_args\": <(test_args),         \"xctest\": <(xctest),         \"test_cases\": <(test_cases),         \"restart\": <(restart)}', '--out-dir', '${ISOLATED_OUTDIR}', '--retries', '3', '--shards', '<(shards)', '--<(xcode_arg_name)', '<(xcode_version)', '--mac-toolchain-cmd', './mac_toolchain', '--xcode-path', 'Xcode.app', '--wpr-tools-path', '<(wpr_tools_path)', '--replay-path', '<(replay_path)', '--iossim', 'src/out/Debug-iphonesimulator/iossim', '--platform', '<(platform)', '--version', '<(version)']}}]]}",
+      "{'conditions': [['OS == \"ios\"', {'variables': {'files': ['<(app_path)/', 'src/ios/build/bots/scripts/', 'src/out/Debug-iphonesimulator/iossim'], 'command': ['src/ios/build/bots/scripts/run.py', '--app', '<(app_path)', '--args-json', '{\"test_args\": <(test_args),         \"xctest\": <(xctest),         \"test_cases\": <(test_cases),         \"restart\": <(restart),         \"xcode-parallelization\": <(xcode_parallelization)}', '--out-dir', '${ISOLATED_OUTDIR}', '--retries', '3', '--shards', '<(shards)', '--<(xcode_arg_name)', '<(xcode_version)', '--mac-toolchain-cmd', './mac_toolchain', '--xcode-path', 'Xcode.app', '--wpr-tools-path', '<(wpr_tools_path)', '--replay-path', '<(replay_path)', '--iossim', 'src/out/Debug-iphonesimulator/iossim', '--platform', '<(platform)', '--version', '<(version)']}}]]}",
       "[BUILDER_CACHE]/linux/template.isolate"
     ],
     "cwd": "[BUILDER_CACHE]/linux/src",
@@ -525,7 +525,7 @@
       "@@@STEP_LOG_LINE@template.isolate@            \"--app\", @@@",
       "@@@STEP_LOG_LINE@template.isolate@            \"<(app_path)\", @@@",
       "@@@STEP_LOG_LINE@template.isolate@            \"--args-json\", @@@",
-      "@@@STEP_LOG_LINE@template.isolate@            \"{\\\"test_args\\\": <(test_args),         \\\"xctest\\\": <(xctest),         \\\"test_cases\\\": <(test_cases),         \\\"restart\\\": <(restart)}\", @@@",
+      "@@@STEP_LOG_LINE@template.isolate@            \"{\\\"test_args\\\": <(test_args),         \\\"xctest\\\": <(xctest),         \\\"test_cases\\\": <(test_cases),         \\\"restart\\\": <(restart),         \\\"xcode-parallelization\\\": <(xcode_parallelization)}\", @@@",
       "@@@STEP_LOG_LINE@template.isolate@            \"--out-dir\", @@@",
       "@@@STEP_LOG_LINE@template.isolate@            \"${ISOLATED_OUTDIR}\", @@@",
       "@@@STEP_LOG_LINE@template.isolate@            \"--retries\", @@@",
diff --git a/scripts/slave/recipes/ios/try.expected/parent.json b/scripts/slave/recipes/ios/try.expected/parent.json
index 166a986..ad10bcf 100644
--- a/scripts/slave/recipes/ios/try.expected/parent.json
+++ b/scripts/slave/recipes/ios/try.expected/parent.json
@@ -550,7 +550,7 @@
       "--json-output",
       "/path/to/tmp/json",
       "copy",
-      "{'conditions': [['OS == \"ios\"', {'variables': {'files': ['<(app_path)/', 'src/ios/build/bots/scripts/', 'src/out/Debug-iphonesimulator/iossim'], 'command': ['src/ios/build/bots/scripts/run.py', '--app', '<(app_path)', '--args-json', '{\"test_args\": <(test_args),         \"xctest\": <(xctest),         \"test_cases\": <(test_cases),         \"restart\": <(restart)}', '--out-dir', '${ISOLATED_OUTDIR}', '--retries', '3', '--shards', '<(shards)', '--<(xcode_arg_name)', '<(xcode_version)', '--mac-toolchain-cmd', './mac_toolchain', '--xcode-path', 'Xcode.app', '--wpr-tools-path', '<(wpr_tools_path)', '--replay-path', '<(replay_path)', '--iossim', 'src/out/Debug-iphonesimulator/iossim', '--platform', '<(platform)', '--version', '<(version)']}}]]}",
+      "{'conditions': [['OS == \"ios\"', {'variables': {'files': ['<(app_path)/', 'src/ios/build/bots/scripts/', 'src/out/Debug-iphonesimulator/iossim'], 'command': ['src/ios/build/bots/scripts/run.py', '--app', '<(app_path)', '--args-json', '{\"test_args\": <(test_args),         \"xctest\": <(xctest),         \"test_cases\": <(test_cases),         \"restart\": <(restart),         \"xcode-parallelization\": <(xcode_parallelization)}', '--out-dir', '${ISOLATED_OUTDIR}', '--retries', '3', '--shards', '<(shards)', '--<(xcode_arg_name)', '<(xcode_version)', '--mac-toolchain-cmd', './mac_toolchain', '--xcode-path', 'Xcode.app', '--wpr-tools-path', '<(wpr_tools_path)', '--replay-path', '<(replay_path)', '--iossim', 'src/out/Debug-iphonesimulator/iossim', '--platform', '<(platform)', '--version', '<(version)']}}]]}",
       "[BUILDER_CACHE]/linux/template.isolate"
     ],
     "cwd": "[BUILDER_CACHE]/linux/src",
@@ -569,7 +569,7 @@
       "@@@STEP_LOG_LINE@template.isolate@            \"--app\", @@@",
       "@@@STEP_LOG_LINE@template.isolate@            \"<(app_path)\", @@@",
       "@@@STEP_LOG_LINE@template.isolate@            \"--args-json\", @@@",
-      "@@@STEP_LOG_LINE@template.isolate@            \"{\\\"test_args\\\": <(test_args),         \\\"xctest\\\": <(xctest),         \\\"test_cases\\\": <(test_cases),         \\\"restart\\\": <(restart)}\", @@@",
+      "@@@STEP_LOG_LINE@template.isolate@            \"{\\\"test_args\\\": <(test_args),         \\\"xctest\\\": <(xctest),         \\\"test_cases\\\": <(test_cases),         \\\"restart\\\": <(restart),         \\\"xcode-parallelization\\\": <(xcode_parallelization)}\", @@@",
       "@@@STEP_LOG_LINE@template.isolate@            \"--out-dir\", @@@",
       "@@@STEP_LOG_LINE@template.isolate@            \"${ISOLATED_OUTDIR}\", @@@",
       "@@@STEP_LOG_LINE@template.isolate@            \"--retries\", @@@",
@@ -614,7 +614,7 @@
       "--json-output",
       "/path/to/tmp/json",
       "copy",
-      "{\n  \"args\": [\n    \"--config-variable\", \n    \"OS\", \n    \"ios\", \n    \"--config-variable\", \n    \"app_path\", \n    \"src/out/Debug-iphonesimulator/fake tests.app\", \n    \"--config-variable\", \n    \"restart\", \n    \"false\", \n    \"--config-variable\", \n    \"shards\", \n    \"1\", \n    \"--config-variable\", \n    \"test_args\", \n    \"[]\", \n    \"--config-variable\", \n    \"test_cases\", \n    \"[]\", \n    \"--config-variable\", \n    \"xctest\", \n    \"false\", \n    \"--config-variable\", \n    \"use_trusted_cert\", \n    \"false\", \n    \"--isolate\", \n    \"[BUILDER_CACHE]/linux/template.isolate\", \n    \"--isolated\", \n    \"[CLEANUP]/isolate_tmp_1/0.isolated\", \n    \"--path-variable\", \n    \"app_path\", \n    \"src/out/Debug-iphonesimulator/fake tests.app\", \n    \"--config-variable\", \n    \"wpr_tools_path\", \n    \"NO_PATH\", \n    \"--config-variable\", \n    \"replay_path\", \n    \"NO_PATH\", \n    \"--config-variable\", \n    \"xcode_arg_name\", \n    \"xcode-build-version\", \n    \"--config-variable\", \n    \"xcode_version\", \n    \"9c40b\", \n    \"--config-variable\", \n    \"platform\", \n    \"fake device\", \n    \"--config-variable\", \n    \"version\", \n    \"8.1\"\n  ], \n  \"dir\": \"[BUILDER_CACHE]/linux\", \n  \"version\": 1\n}",
+      "{\n  \"args\": [\n    \"--config-variable\", \n    \"OS\", \n    \"ios\", \n    \"--config-variable\", \n    \"app_path\", \n    \"src/out/Debug-iphonesimulator/fake tests.app\", \n    \"--config-variable\", \n    \"restart\", \n    \"false\", \n    \"--config-variable\", \n    \"shards\", \n    \"1\", \n    \"--config-variable\", \n    \"test_args\", \n    \"[]\", \n    \"--config-variable\", \n    \"xcode_parallelization\", \n    \"false\", \n    \"--config-variable\", \n    \"test_cases\", \n    \"[]\", \n    \"--config-variable\", \n    \"xctest\", \n    \"false\", \n    \"--config-variable\", \n    \"use_trusted_cert\", \n    \"false\", \n    \"--isolate\", \n    \"[BUILDER_CACHE]/linux/template.isolate\", \n    \"--isolated\", \n    \"[CLEANUP]/isolate_tmp_1/0.isolated\", \n    \"--path-variable\", \n    \"app_path\", \n    \"src/out/Debug-iphonesimulator/fake tests.app\", \n    \"--config-variable\", \n    \"wpr_tools_path\", \n    \"NO_PATH\", \n    \"--config-variable\", \n    \"replay_path\", \n    \"NO_PATH\", \n    \"--config-variable\", \n    \"xcode_arg_name\", \n    \"xcode-build-version\", \n    \"--config-variable\", \n    \"xcode_version\", \n    \"9c40b\", \n    \"--config-variable\", \n    \"platform\", \n    \"fake device\", \n    \"--config-variable\", \n    \"version\", \n    \"8.1\"\n  ], \n  \"dir\": \"[BUILDER_CACHE]/linux\", \n  \"version\": 1\n}",
       "[CLEANUP]/isolate_tmp_1/0.isolated.gen.json"
     ],
     "cwd": "[BUILDER_CACHE]/linux/src",
@@ -641,6 +641,9 @@
       "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"test_args\", @@@",
       "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"[]\", @@@",
       "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"--config-variable\", @@@",
+      "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"xcode_parallelization\", @@@",
+      "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"false\", @@@",
+      "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"--config-variable\", @@@",
       "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"test_cases\", @@@",
       "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"[]\", @@@",
       "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"--config-variable\", @@@",
diff --git a/scripts/slave/recipes/ios/unified_builder_tester.expected/basic.json b/scripts/slave/recipes/ios/unified_builder_tester.expected/basic.json
index 56345b4..4ad36a6 100644
--- a/scripts/slave/recipes/ios/unified_builder_tester.expected/basic.json
+++ b/scripts/slave/recipes/ios/unified_builder_tester.expected/basic.json
@@ -483,7 +483,7 @@
       "--json-output",
       "/path/to/tmp/json",
       "copy",
-      "{'conditions': [['OS == \"ios\"', {'variables': {'files': ['<(app_path)/', 'src/ios/build/bots/scripts/', 'src/out/Debug-iphonesimulator/iossim'], 'command': ['src/ios/build/bots/scripts/run.py', '--app', '<(app_path)', '--args-json', '{\"test_args\": <(test_args),         \"xctest\": <(xctest),         \"test_cases\": <(test_cases),         \"restart\": <(restart)}', '--out-dir', '${ISOLATED_OUTDIR}', '--retries', '3', '--shards', '<(shards)', '--<(xcode_arg_name)', '<(xcode_version)', '--mac-toolchain-cmd', './mac_toolchain', '--xcode-path', 'Xcode.app', '--wpr-tools-path', '<(wpr_tools_path)', '--replay-path', '<(replay_path)', '--iossim', 'src/out/Debug-iphonesimulator/iossim', '--platform', '<(platform)', '--version', '<(version)']}}]]}",
+      "{'conditions': [['OS == \"ios\"', {'variables': {'files': ['<(app_path)/', 'src/ios/build/bots/scripts/', 'src/out/Debug-iphonesimulator/iossim'], 'command': ['src/ios/build/bots/scripts/run.py', '--app', '<(app_path)', '--args-json', '{\"test_args\": <(test_args),         \"xctest\": <(xctest),         \"test_cases\": <(test_cases),         \"restart\": <(restart),         \"xcode-parallelization\": <(xcode_parallelization)}', '--out-dir', '${ISOLATED_OUTDIR}', '--retries', '3', '--shards', '<(shards)', '--<(xcode_arg_name)', '<(xcode_version)', '--mac-toolchain-cmd', './mac_toolchain', '--xcode-path', 'Xcode.app', '--wpr-tools-path', '<(wpr_tools_path)', '--replay-path', '<(replay_path)', '--iossim', 'src/out/Debug-iphonesimulator/iossim', '--platform', '<(platform)', '--version', '<(version)']}}]]}",
       "[BUILDER_CACHE]/ios/template.isolate"
     ],
     "cwd": "[BUILDER_CACHE]/ios/src",
@@ -502,7 +502,7 @@
       "@@@STEP_LOG_LINE@template.isolate@            \"--app\", @@@",
       "@@@STEP_LOG_LINE@template.isolate@            \"<(app_path)\", @@@",
       "@@@STEP_LOG_LINE@template.isolate@            \"--args-json\", @@@",
-      "@@@STEP_LOG_LINE@template.isolate@            \"{\\\"test_args\\\": <(test_args),         \\\"xctest\\\": <(xctest),         \\\"test_cases\\\": <(test_cases),         \\\"restart\\\": <(restart)}\", @@@",
+      "@@@STEP_LOG_LINE@template.isolate@            \"{\\\"test_args\\\": <(test_args),         \\\"xctest\\\": <(xctest),         \\\"test_cases\\\": <(test_cases),         \\\"restart\\\": <(restart),         \\\"xcode-parallelization\\\": <(xcode_parallelization)}\", @@@",
       "@@@STEP_LOG_LINE@template.isolate@            \"--out-dir\", @@@",
       "@@@STEP_LOG_LINE@template.isolate@            \"${ISOLATED_OUTDIR}\", @@@",
       "@@@STEP_LOG_LINE@template.isolate@            \"--retries\", @@@",
@@ -547,7 +547,7 @@
       "--json-output",
       "/path/to/tmp/json",
       "copy",
-      "{\n  \"args\": [\n    \"--config-variable\", \n    \"OS\", \n    \"ios\", \n    \"--config-variable\", \n    \"app_path\", \n    \"src/out/Debug-iphonesimulator/fake tests 1.app\", \n    \"--config-variable\", \n    \"restart\", \n    \"false\", \n    \"--config-variable\", \n    \"shards\", \n    \"1\", \n    \"--config-variable\", \n    \"test_args\", \n    \"[]\", \n    \"--config-variable\", \n    \"test_cases\", \n    \"[]\", \n    \"--config-variable\", \n    \"xctest\", \n    \"false\", \n    \"--config-variable\", \n    \"use_trusted_cert\", \n    \"false\", \n    \"--isolate\", \n    \"[BUILDER_CACHE]/ios/template.isolate\", \n    \"--isolated\", \n    \"[CLEANUP]/isolate_tmp_2/0.isolated\", \n    \"--path-variable\", \n    \"app_path\", \n    \"src/out/Debug-iphonesimulator/fake tests 1.app\", \n    \"--config-variable\", \n    \"wpr_tools_path\", \n    \"NO_PATH\", \n    \"--config-variable\", \n    \"replay_path\", \n    \"NO_PATH\", \n    \"--config-variable\", \n    \"xcode_arg_name\", \n    \"xcode-build-version\", \n    \"--config-variable\", \n    \"xcode_version\", \n    \"9c40b\", \n    \"--config-variable\", \n    \"platform\", \n    \"fake device\", \n    \"--config-variable\", \n    \"version\", \n    \"8.0\"\n  ], \n  \"dir\": \"[BUILDER_CACHE]/ios\", \n  \"version\": 1\n}",
+      "{\n  \"args\": [\n    \"--config-variable\", \n    \"OS\", \n    \"ios\", \n    \"--config-variable\", \n    \"app_path\", \n    \"src/out/Debug-iphonesimulator/fake tests 1.app\", \n    \"--config-variable\", \n    \"restart\", \n    \"false\", \n    \"--config-variable\", \n    \"shards\", \n    \"1\", \n    \"--config-variable\", \n    \"test_args\", \n    \"[]\", \n    \"--config-variable\", \n    \"xcode_parallelization\", \n    \"false\", \n    \"--config-variable\", \n    \"test_cases\", \n    \"[]\", \n    \"--config-variable\", \n    \"xctest\", \n    \"false\", \n    \"--config-variable\", \n    \"use_trusted_cert\", \n    \"false\", \n    \"--isolate\", \n    \"[BUILDER_CACHE]/ios/template.isolate\", \n    \"--isolated\", \n    \"[CLEANUP]/isolate_tmp_2/0.isolated\", \n    \"--path-variable\", \n    \"app_path\", \n    \"src/out/Debug-iphonesimulator/fake tests 1.app\", \n    \"--config-variable\", \n    \"wpr_tools_path\", \n    \"NO_PATH\", \n    \"--config-variable\", \n    \"replay_path\", \n    \"NO_PATH\", \n    \"--config-variable\", \n    \"xcode_arg_name\", \n    \"xcode-build-version\", \n    \"--config-variable\", \n    \"xcode_version\", \n    \"9c40b\", \n    \"--config-variable\", \n    \"platform\", \n    \"fake device\", \n    \"--config-variable\", \n    \"version\", \n    \"8.0\"\n  ], \n  \"dir\": \"[BUILDER_CACHE]/ios\", \n  \"version\": 1\n}",
       "[CLEANUP]/isolate_tmp_2/0.isolated.gen.json"
     ],
     "cwd": "[BUILDER_CACHE]/ios/src",
@@ -574,6 +574,9 @@
       "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"test_args\", @@@",
       "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"[]\", @@@",
       "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"--config-variable\", @@@",
+      "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"xcode_parallelization\", @@@",
+      "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"false\", @@@",
+      "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"--config-variable\", @@@",
       "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"test_cases\", @@@",
       "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"[]\", @@@",
       "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"--config-variable\", @@@",
@@ -622,7 +625,7 @@
       "--json-output",
       "/path/to/tmp/json",
       "copy",
-      "{\n  \"args\": [\n    \"--config-variable\", \n    \"OS\", \n    \"ios\", \n    \"--config-variable\", \n    \"app_path\", \n    \"src/out/Debug-iphonesimulator/fake tests 2.app\", \n    \"--config-variable\", \n    \"restart\", \n    \"false\", \n    \"--config-variable\", \n    \"shards\", \n    \"1\", \n    \"--config-variable\", \n    \"test_args\", \n    \"[]\", \n    \"--config-variable\", \n    \"test_cases\", \n    \"[]\", \n    \"--config-variable\", \n    \"xctest\", \n    \"false\", \n    \"--config-variable\", \n    \"use_trusted_cert\", \n    \"false\", \n    \"--isolate\", \n    \"[BUILDER_CACHE]/ios/template.isolate\", \n    \"--isolated\", \n    \"[CLEANUP]/isolate_tmp_2/1.isolated\", \n    \"--path-variable\", \n    \"app_path\", \n    \"src/out/Debug-iphonesimulator/fake tests 2.app\", \n    \"--config-variable\", \n    \"wpr_tools_path\", \n    \"NO_PATH\", \n    \"--config-variable\", \n    \"replay_path\", \n    \"NO_PATH\", \n    \"--config-variable\", \n    \"xcode_arg_name\", \n    \"xcode-build-version\", \n    \"--config-variable\", \n    \"xcode_version\", \n    \"9c40b\", \n    \"--config-variable\", \n    \"platform\", \n    \"fake device\", \n    \"--config-variable\", \n    \"version\", \n    \"7.1\"\n  ], \n  \"dir\": \"[BUILDER_CACHE]/ios\", \n  \"version\": 1\n}",
+      "{\n  \"args\": [\n    \"--config-variable\", \n    \"OS\", \n    \"ios\", \n    \"--config-variable\", \n    \"app_path\", \n    \"src/out/Debug-iphonesimulator/fake tests 2.app\", \n    \"--config-variable\", \n    \"restart\", \n    \"false\", \n    \"--config-variable\", \n    \"shards\", \n    \"1\", \n    \"--config-variable\", \n    \"test_args\", \n    \"[]\", \n    \"--config-variable\", \n    \"xcode_parallelization\", \n    \"false\", \n    \"--config-variable\", \n    \"test_cases\", \n    \"[]\", \n    \"--config-variable\", \n    \"xctest\", \n    \"false\", \n    \"--config-variable\", \n    \"use_trusted_cert\", \n    \"false\", \n    \"--isolate\", \n    \"[BUILDER_CACHE]/ios/template.isolate\", \n    \"--isolated\", \n    \"[CLEANUP]/isolate_tmp_2/1.isolated\", \n    \"--path-variable\", \n    \"app_path\", \n    \"src/out/Debug-iphonesimulator/fake tests 2.app\", \n    \"--config-variable\", \n    \"wpr_tools_path\", \n    \"NO_PATH\", \n    \"--config-variable\", \n    \"replay_path\", \n    \"NO_PATH\", \n    \"--config-variable\", \n    \"xcode_arg_name\", \n    \"xcode-build-version\", \n    \"--config-variable\", \n    \"xcode_version\", \n    \"9c40b\", \n    \"--config-variable\", \n    \"platform\", \n    \"fake device\", \n    \"--config-variable\", \n    \"version\", \n    \"7.1\"\n  ], \n  \"dir\": \"[BUILDER_CACHE]/ios\", \n  \"version\": 1\n}",
       "[CLEANUP]/isolate_tmp_2/1.isolated.gen.json"
     ],
     "cwd": "[BUILDER_CACHE]/ios/src",
@@ -649,6 +652,9 @@
       "@@@STEP_LOG_LINE@1.isolated.gen.json@    \"test_args\", @@@",
       "@@@STEP_LOG_LINE@1.isolated.gen.json@    \"[]\", @@@",
       "@@@STEP_LOG_LINE@1.isolated.gen.json@    \"--config-variable\", @@@",
+      "@@@STEP_LOG_LINE@1.isolated.gen.json@    \"xcode_parallelization\", @@@",
+      "@@@STEP_LOG_LINE@1.isolated.gen.json@    \"false\", @@@",
+      "@@@STEP_LOG_LINE@1.isolated.gen.json@    \"--config-variable\", @@@",
       "@@@STEP_LOG_LINE@1.isolated.gen.json@    \"test_cases\", @@@",
       "@@@STEP_LOG_LINE@1.isolated.gen.json@    \"[]\", @@@",
       "@@@STEP_LOG_LINE@1.isolated.gen.json@    \"--config-variable\", @@@",
@@ -697,7 +703,7 @@
       "--json-output",
       "/path/to/tmp/json",
       "copy",
-      "{\n  \"args\": [\n    \"--config-variable\", \n    \"OS\", \n    \"ios\", \n    \"--config-variable\", \n    \"app_path\", \n    \"src/out/Debug-iphonesimulator/fake_eg_test_host.app\", \n    \"--config-variable\", \n    \"restart\", \n    \"false\", \n    \"--config-variable\", \n    \"shards\", \n    \"1\", \n    \"--config-variable\", \n    \"test_args\", \n    \"[]\", \n    \"--config-variable\", \n    \"test_cases\", \n    \"[]\", \n    \"--config-variable\", \n    \"xctest\", \n    \"true\", \n    \"--config-variable\", \n    \"use_trusted_cert\", \n    \"false\", \n    \"--isolate\", \n    \"[BUILDER_CACHE]/ios/template.isolate\", \n    \"--isolated\", \n    \"[CLEANUP]/isolate_tmp_2/2.isolated\", \n    \"--path-variable\", \n    \"app_path\", \n    \"src/out/Debug-iphonesimulator/fake_eg_test_host.app\", \n    \"--config-variable\", \n    \"wpr_tools_path\", \n    \"NO_PATH\", \n    \"--config-variable\", \n    \"replay_path\", \n    \"NO_PATH\", \n    \"--config-variable\", \n    \"xcode_arg_name\", \n    \"xcode-build-version\", \n    \"--config-variable\", \n    \"xcode_version\", \n    \"9c40b\", \n    \"--config-variable\", \n    \"platform\", \n    \"fake device 3\", \n    \"--config-variable\", \n    \"version\", \n    \"9.3\"\n  ], \n  \"dir\": \"[BUILDER_CACHE]/ios\", \n  \"version\": 1\n}",
+      "{\n  \"args\": [\n    \"--config-variable\", \n    \"OS\", \n    \"ios\", \n    \"--config-variable\", \n    \"app_path\", \n    \"src/out/Debug-iphonesimulator/fake_eg_test_host.app\", \n    \"--config-variable\", \n    \"restart\", \n    \"false\", \n    \"--config-variable\", \n    \"shards\", \n    \"1\", \n    \"--config-variable\", \n    \"test_args\", \n    \"[]\", \n    \"--config-variable\", \n    \"xcode_parallelization\", \n    \"false\", \n    \"--config-variable\", \n    \"test_cases\", \n    \"[]\", \n    \"--config-variable\", \n    \"xctest\", \n    \"true\", \n    \"--config-variable\", \n    \"use_trusted_cert\", \n    \"false\", \n    \"--isolate\", \n    \"[BUILDER_CACHE]/ios/template.isolate\", \n    \"--isolated\", \n    \"[CLEANUP]/isolate_tmp_2/2.isolated\", \n    \"--path-variable\", \n    \"app_path\", \n    \"src/out/Debug-iphonesimulator/fake_eg_test_host.app\", \n    \"--config-variable\", \n    \"wpr_tools_path\", \n    \"NO_PATH\", \n    \"--config-variable\", \n    \"replay_path\", \n    \"NO_PATH\", \n    \"--config-variable\", \n    \"xcode_arg_name\", \n    \"xcode-build-version\", \n    \"--config-variable\", \n    \"xcode_version\", \n    \"9c40b\", \n    \"--config-variable\", \n    \"platform\", \n    \"fake device 3\", \n    \"--config-variable\", \n    \"version\", \n    \"9.3\"\n  ], \n  \"dir\": \"[BUILDER_CACHE]/ios\", \n  \"version\": 1\n}",
       "[CLEANUP]/isolate_tmp_2/2.isolated.gen.json"
     ],
     "cwd": "[BUILDER_CACHE]/ios/src",
@@ -724,6 +730,9 @@
       "@@@STEP_LOG_LINE@2.isolated.gen.json@    \"test_args\", @@@",
       "@@@STEP_LOG_LINE@2.isolated.gen.json@    \"[]\", @@@",
       "@@@STEP_LOG_LINE@2.isolated.gen.json@    \"--config-variable\", @@@",
+      "@@@STEP_LOG_LINE@2.isolated.gen.json@    \"xcode_parallelization\", @@@",
+      "@@@STEP_LOG_LINE@2.isolated.gen.json@    \"false\", @@@",
+      "@@@STEP_LOG_LINE@2.isolated.gen.json@    \"--config-variable\", @@@",
       "@@@STEP_LOG_LINE@2.isolated.gen.json@    \"test_cases\", @@@",
       "@@@STEP_LOG_LINE@2.isolated.gen.json@    \"[]\", @@@",
       "@@@STEP_LOG_LINE@2.isolated.gen.json@    \"--config-variable\", @@@",
diff --git a/scripts/slave/recipes/ios/unified_builder_tester.expected/basic_experimental.json b/scripts/slave/recipes/ios/unified_builder_tester.expected/basic_experimental.json
index 1c31d5a..ae5cc85 100644
--- a/scripts/slave/recipes/ios/unified_builder_tester.expected/basic_experimental.json
+++ b/scripts/slave/recipes/ios/unified_builder_tester.expected/basic_experimental.json
@@ -414,7 +414,7 @@
       "--json-output",
       "/path/to/tmp/json",
       "copy",
-      "{'conditions': [['OS == \"ios\"', {'variables': {'files': ['<(app_path)/', 'src/ios/build/bots/scripts/', 'src/out/Debug-iphonesimulator/iossim'], 'command': ['src/ios/build/bots/scripts/run.py', '--app', '<(app_path)', '--args-json', '{\"test_args\": <(test_args),         \"xctest\": <(xctest),         \"test_cases\": <(test_cases),         \"restart\": <(restart)}', '--out-dir', '${ISOLATED_OUTDIR}', '--retries', '3', '--shards', '<(shards)', '--<(xcode_arg_name)', '<(xcode_version)', '--mac-toolchain-cmd', './mac_toolchain', '--xcode-path', 'Xcode.app', '--wpr-tools-path', '<(wpr_tools_path)', '--replay-path', '<(replay_path)', '--iossim', 'src/out/Debug-iphonesimulator/iossim', '--platform', '<(platform)', '--version', '<(version)']}}]]}",
+      "{'conditions': [['OS == \"ios\"', {'variables': {'files': ['<(app_path)/', 'src/ios/build/bots/scripts/', 'src/out/Debug-iphonesimulator/iossim'], 'command': ['src/ios/build/bots/scripts/run.py', '--app', '<(app_path)', '--args-json', '{\"test_args\": <(test_args),         \"xctest\": <(xctest),         \"test_cases\": <(test_cases),         \"restart\": <(restart),         \"xcode-parallelization\": <(xcode_parallelization)}', '--out-dir', '${ISOLATED_OUTDIR}', '--retries', '3', '--shards', '<(shards)', '--<(xcode_arg_name)', '<(xcode_version)', '--mac-toolchain-cmd', './mac_toolchain', '--xcode-path', 'Xcode.app', '--wpr-tools-path', '<(wpr_tools_path)', '--replay-path', '<(replay_path)', '--iossim', 'src/out/Debug-iphonesimulator/iossim', '--platform', '<(platform)', '--version', '<(version)']}}]]}",
       "[CACHE]/builder/template.isolate"
     ],
     "cwd": "[CACHE]/builder/src",
@@ -433,7 +433,7 @@
       "@@@STEP_LOG_LINE@template.isolate@            \"--app\", @@@",
       "@@@STEP_LOG_LINE@template.isolate@            \"<(app_path)\", @@@",
       "@@@STEP_LOG_LINE@template.isolate@            \"--args-json\", @@@",
-      "@@@STEP_LOG_LINE@template.isolate@            \"{\\\"test_args\\\": <(test_args),         \\\"xctest\\\": <(xctest),         \\\"test_cases\\\": <(test_cases),         \\\"restart\\\": <(restart)}\", @@@",
+      "@@@STEP_LOG_LINE@template.isolate@            \"{\\\"test_args\\\": <(test_args),         \\\"xctest\\\": <(xctest),         \\\"test_cases\\\": <(test_cases),         \\\"restart\\\": <(restart),         \\\"xcode-parallelization\\\": <(xcode_parallelization)}\", @@@",
       "@@@STEP_LOG_LINE@template.isolate@            \"--out-dir\", @@@",
       "@@@STEP_LOG_LINE@template.isolate@            \"${ISOLATED_OUTDIR}\", @@@",
       "@@@STEP_LOG_LINE@template.isolate@            \"--retries\", @@@",
@@ -478,7 +478,7 @@
       "--json-output",
       "/path/to/tmp/json",
       "copy",
-      "{\n  \"args\": [\n    \"--config-variable\", \n    \"OS\", \n    \"ios\", \n    \"--config-variable\", \n    \"app_path\", \n    \"src/out/Debug-iphonesimulator/fake tests 1.app\", \n    \"--config-variable\", \n    \"restart\", \n    \"false\", \n    \"--config-variable\", \n    \"shards\", \n    \"1\", \n    \"--config-variable\", \n    \"test_args\", \n    \"[]\", \n    \"--config-variable\", \n    \"test_cases\", \n    \"[]\", \n    \"--config-variable\", \n    \"xctest\", \n    \"false\", \n    \"--config-variable\", \n    \"use_trusted_cert\", \n    \"false\", \n    \"--isolate\", \n    \"[CACHE]/builder/template.isolate\", \n    \"--isolated\", \n    \"[CLEANUP]/isolate_tmp_1/0.isolated\", \n    \"--path-variable\", \n    \"app_path\", \n    \"src/out/Debug-iphonesimulator/fake tests 1.app\", \n    \"--config-variable\", \n    \"wpr_tools_path\", \n    \"NO_PATH\", \n    \"--config-variable\", \n    \"replay_path\", \n    \"NO_PATH\", \n    \"--config-variable\", \n    \"xcode_arg_name\", \n    \"xcode-build-version\", \n    \"--config-variable\", \n    \"xcode_version\", \n    \"9c40b\", \n    \"--config-variable\", \n    \"platform\", \n    \"fake device\", \n    \"--config-variable\", \n    \"version\", \n    \"8.0\"\n  ], \n  \"dir\": \"[CACHE]/builder\", \n  \"version\": 1\n}",
+      "{\n  \"args\": [\n    \"--config-variable\", \n    \"OS\", \n    \"ios\", \n    \"--config-variable\", \n    \"app_path\", \n    \"src/out/Debug-iphonesimulator/fake tests 1.app\", \n    \"--config-variable\", \n    \"restart\", \n    \"false\", \n    \"--config-variable\", \n    \"shards\", \n    \"1\", \n    \"--config-variable\", \n    \"test_args\", \n    \"[]\", \n    \"--config-variable\", \n    \"xcode_parallelization\", \n    \"false\", \n    \"--config-variable\", \n    \"test_cases\", \n    \"[]\", \n    \"--config-variable\", \n    \"xctest\", \n    \"false\", \n    \"--config-variable\", \n    \"use_trusted_cert\", \n    \"false\", \n    \"--isolate\", \n    \"[CACHE]/builder/template.isolate\", \n    \"--isolated\", \n    \"[CLEANUP]/isolate_tmp_1/0.isolated\", \n    \"--path-variable\", \n    \"app_path\", \n    \"src/out/Debug-iphonesimulator/fake tests 1.app\", \n    \"--config-variable\", \n    \"wpr_tools_path\", \n    \"NO_PATH\", \n    \"--config-variable\", \n    \"replay_path\", \n    \"NO_PATH\", \n    \"--config-variable\", \n    \"xcode_arg_name\", \n    \"xcode-build-version\", \n    \"--config-variable\", \n    \"xcode_version\", \n    \"9c40b\", \n    \"--config-variable\", \n    \"platform\", \n    \"fake device\", \n    \"--config-variable\", \n    \"version\", \n    \"8.0\"\n  ], \n  \"dir\": \"[CACHE]/builder\", \n  \"version\": 1\n}",
       "[CLEANUP]/isolate_tmp_1/0.isolated.gen.json"
     ],
     "cwd": "[CACHE]/builder/src",
@@ -505,6 +505,9 @@
       "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"test_args\", @@@",
       "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"[]\", @@@",
       "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"--config-variable\", @@@",
+      "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"xcode_parallelization\", @@@",
+      "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"false\", @@@",
+      "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"--config-variable\", @@@",
       "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"test_cases\", @@@",
       "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"[]\", @@@",
       "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"--config-variable\", @@@",
@@ -553,7 +556,7 @@
       "--json-output",
       "/path/to/tmp/json",
       "copy",
-      "{\n  \"args\": [\n    \"--config-variable\", \n    \"OS\", \n    \"ios\", \n    \"--config-variable\", \n    \"app_path\", \n    \"src/out/Debug-iphonesimulator/fake tests 2.app\", \n    \"--config-variable\", \n    \"restart\", \n    \"false\", \n    \"--config-variable\", \n    \"shards\", \n    \"1\", \n    \"--config-variable\", \n    \"test_args\", \n    \"[]\", \n    \"--config-variable\", \n    \"test_cases\", \n    \"[]\", \n    \"--config-variable\", \n    \"xctest\", \n    \"false\", \n    \"--config-variable\", \n    \"use_trusted_cert\", \n    \"false\", \n    \"--isolate\", \n    \"[CACHE]/builder/template.isolate\", \n    \"--isolated\", \n    \"[CLEANUP]/isolate_tmp_1/1.isolated\", \n    \"--path-variable\", \n    \"app_path\", \n    \"src/out/Debug-iphonesimulator/fake tests 2.app\", \n    \"--config-variable\", \n    \"wpr_tools_path\", \n    \"NO_PATH\", \n    \"--config-variable\", \n    \"replay_path\", \n    \"NO_PATH\", \n    \"--config-variable\", \n    \"xcode_arg_name\", \n    \"xcode-build-version\", \n    \"--config-variable\", \n    \"xcode_version\", \n    \"9c40b\", \n    \"--config-variable\", \n    \"platform\", \n    \"fake device\", \n    \"--config-variable\", \n    \"version\", \n    \"7.1\"\n  ], \n  \"dir\": \"[CACHE]/builder\", \n  \"version\": 1\n}",
+      "{\n  \"args\": [\n    \"--config-variable\", \n    \"OS\", \n    \"ios\", \n    \"--config-variable\", \n    \"app_path\", \n    \"src/out/Debug-iphonesimulator/fake tests 2.app\", \n    \"--config-variable\", \n    \"restart\", \n    \"false\", \n    \"--config-variable\", \n    \"shards\", \n    \"1\", \n    \"--config-variable\", \n    \"test_args\", \n    \"[]\", \n    \"--config-variable\", \n    \"xcode_parallelization\", \n    \"false\", \n    \"--config-variable\", \n    \"test_cases\", \n    \"[]\", \n    \"--config-variable\", \n    \"xctest\", \n    \"false\", \n    \"--config-variable\", \n    \"use_trusted_cert\", \n    \"false\", \n    \"--isolate\", \n    \"[CACHE]/builder/template.isolate\", \n    \"--isolated\", \n    \"[CLEANUP]/isolate_tmp_1/1.isolated\", \n    \"--path-variable\", \n    \"app_path\", \n    \"src/out/Debug-iphonesimulator/fake tests 2.app\", \n    \"--config-variable\", \n    \"wpr_tools_path\", \n    \"NO_PATH\", \n    \"--config-variable\", \n    \"replay_path\", \n    \"NO_PATH\", \n    \"--config-variable\", \n    \"xcode_arg_name\", \n    \"xcode-build-version\", \n    \"--config-variable\", \n    \"xcode_version\", \n    \"9c40b\", \n    \"--config-variable\", \n    \"platform\", \n    \"fake device\", \n    \"--config-variable\", \n    \"version\", \n    \"7.1\"\n  ], \n  \"dir\": \"[CACHE]/builder\", \n  \"version\": 1\n}",
       "[CLEANUP]/isolate_tmp_1/1.isolated.gen.json"
     ],
     "cwd": "[CACHE]/builder/src",
@@ -580,6 +583,9 @@
       "@@@STEP_LOG_LINE@1.isolated.gen.json@    \"test_args\", @@@",
       "@@@STEP_LOG_LINE@1.isolated.gen.json@    \"[]\", @@@",
       "@@@STEP_LOG_LINE@1.isolated.gen.json@    \"--config-variable\", @@@",
+      "@@@STEP_LOG_LINE@1.isolated.gen.json@    \"xcode_parallelization\", @@@",
+      "@@@STEP_LOG_LINE@1.isolated.gen.json@    \"false\", @@@",
+      "@@@STEP_LOG_LINE@1.isolated.gen.json@    \"--config-variable\", @@@",
       "@@@STEP_LOG_LINE@1.isolated.gen.json@    \"test_cases\", @@@",
       "@@@STEP_LOG_LINE@1.isolated.gen.json@    \"[]\", @@@",
       "@@@STEP_LOG_LINE@1.isolated.gen.json@    \"--config-variable\", @@@",
@@ -628,7 +634,7 @@
       "--json-output",
       "/path/to/tmp/json",
       "copy",
-      "{\n  \"args\": [\n    \"--config-variable\", \n    \"OS\", \n    \"ios\", \n    \"--config-variable\", \n    \"app_path\", \n    \"src/out/Debug-iphonesimulator/fake_eg_test_host.app\", \n    \"--config-variable\", \n    \"restart\", \n    \"false\", \n    \"--config-variable\", \n    \"shards\", \n    \"1\", \n    \"--config-variable\", \n    \"test_args\", \n    \"[]\", \n    \"--config-variable\", \n    \"test_cases\", \n    \"[]\", \n    \"--config-variable\", \n    \"xctest\", \n    \"true\", \n    \"--config-variable\", \n    \"use_trusted_cert\", \n    \"false\", \n    \"--isolate\", \n    \"[CACHE]/builder/template.isolate\", \n    \"--isolated\", \n    \"[CLEANUP]/isolate_tmp_1/2.isolated\", \n    \"--path-variable\", \n    \"app_path\", \n    \"src/out/Debug-iphonesimulator/fake_eg_test_host.app\", \n    \"--config-variable\", \n    \"wpr_tools_path\", \n    \"NO_PATH\", \n    \"--config-variable\", \n    \"replay_path\", \n    \"NO_PATH\", \n    \"--config-variable\", \n    \"xcode_arg_name\", \n    \"xcode-build-version\", \n    \"--config-variable\", \n    \"xcode_version\", \n    \"9c40b\", \n    \"--config-variable\", \n    \"platform\", \n    \"fake device 3\", \n    \"--config-variable\", \n    \"version\", \n    \"9.3\"\n  ], \n  \"dir\": \"[CACHE]/builder\", \n  \"version\": 1\n}",
+      "{\n  \"args\": [\n    \"--config-variable\", \n    \"OS\", \n    \"ios\", \n    \"--config-variable\", \n    \"app_path\", \n    \"src/out/Debug-iphonesimulator/fake_eg_test_host.app\", \n    \"--config-variable\", \n    \"restart\", \n    \"false\", \n    \"--config-variable\", \n    \"shards\", \n    \"1\", \n    \"--config-variable\", \n    \"test_args\", \n    \"[]\", \n    \"--config-variable\", \n    \"xcode_parallelization\", \n    \"false\", \n    \"--config-variable\", \n    \"test_cases\", \n    \"[]\", \n    \"--config-variable\", \n    \"xctest\", \n    \"true\", \n    \"--config-variable\", \n    \"use_trusted_cert\", \n    \"false\", \n    \"--isolate\", \n    \"[CACHE]/builder/template.isolate\", \n    \"--isolated\", \n    \"[CLEANUP]/isolate_tmp_1/2.isolated\", \n    \"--path-variable\", \n    \"app_path\", \n    \"src/out/Debug-iphonesimulator/fake_eg_test_host.app\", \n    \"--config-variable\", \n    \"wpr_tools_path\", \n    \"NO_PATH\", \n    \"--config-variable\", \n    \"replay_path\", \n    \"NO_PATH\", \n    \"--config-variable\", \n    \"xcode_arg_name\", \n    \"xcode-build-version\", \n    \"--config-variable\", \n    \"xcode_version\", \n    \"9c40b\", \n    \"--config-variable\", \n    \"platform\", \n    \"fake device 3\", \n    \"--config-variable\", \n    \"version\", \n    \"9.3\"\n  ], \n  \"dir\": \"[CACHE]/builder\", \n  \"version\": 1\n}",
       "[CLEANUP]/isolate_tmp_1/2.isolated.gen.json"
     ],
     "cwd": "[CACHE]/builder/src",
@@ -655,6 +661,9 @@
       "@@@STEP_LOG_LINE@2.isolated.gen.json@    \"test_args\", @@@",
       "@@@STEP_LOG_LINE@2.isolated.gen.json@    \"[]\", @@@",
       "@@@STEP_LOG_LINE@2.isolated.gen.json@    \"--config-variable\", @@@",
+      "@@@STEP_LOG_LINE@2.isolated.gen.json@    \"xcode_parallelization\", @@@",
+      "@@@STEP_LOG_LINE@2.isolated.gen.json@    \"false\", @@@",
+      "@@@STEP_LOG_LINE@2.isolated.gen.json@    \"--config-variable\", @@@",
       "@@@STEP_LOG_LINE@2.isolated.gen.json@    \"test_cases\", @@@",
       "@@@STEP_LOG_LINE@2.isolated.gen.json@    \"[]\", @@@",
       "@@@STEP_LOG_LINE@2.isolated.gen.json@    \"--config-variable\", @@@",
diff --git a/scripts/slave/recipes/ios/unified_builder_tester.expected/goma.json b/scripts/slave/recipes/ios/unified_builder_tester.expected/goma.json
index 35922ad..ff14398 100644
--- a/scripts/slave/recipes/ios/unified_builder_tester.expected/goma.json
+++ b/scripts/slave/recipes/ios/unified_builder_tester.expected/goma.json
@@ -645,7 +645,7 @@
       "--json-output",
       "/path/to/tmp/json",
       "copy",
-      "{'conditions': [['OS == \"ios\"', {'variables': {'files': ['<(app_path)/', 'src/ios/build/bots/scripts/'], 'command': ['src/ios/build/bots/scripts/run.py', '--app', '<(app_path)', '--args-json', '{\"test_args\": <(test_args),         \"xctest\": <(xctest),         \"test_cases\": <(test_cases),         \"restart\": <(restart)}', '--out-dir', '${ISOLATED_OUTDIR}', '--retries', '3', '--shards', '<(shards)', '--<(xcode_arg_name)', '<(xcode_version)', '--mac-toolchain-cmd', './mac_toolchain', '--xcode-path', 'Xcode.app', '--wpr-tools-path', '<(wpr_tools_path)', '--replay-path', '<(replay_path)']}}]]}",
+      "{'conditions': [['OS == \"ios\"', {'variables': {'files': ['<(app_path)/', 'src/ios/build/bots/scripts/'], 'command': ['src/ios/build/bots/scripts/run.py', '--app', '<(app_path)', '--args-json', '{\"test_args\": <(test_args),         \"xctest\": <(xctest),         \"test_cases\": <(test_cases),         \"restart\": <(restart),         \"xcode-parallelization\": <(xcode_parallelization)}', '--out-dir', '${ISOLATED_OUTDIR}', '--retries', '3', '--shards', '<(shards)', '--<(xcode_arg_name)', '<(xcode_version)', '--mac-toolchain-cmd', './mac_toolchain', '--xcode-path', 'Xcode.app', '--wpr-tools-path', '<(wpr_tools_path)', '--replay-path', '<(replay_path)']}}]]}",
       "[BUILDER_CACHE]/ios/template.isolate"
     ],
     "cwd": "[BUILDER_CACHE]/ios/src",
@@ -664,7 +664,7 @@
       "@@@STEP_LOG_LINE@template.isolate@            \"--app\", @@@",
       "@@@STEP_LOG_LINE@template.isolate@            \"<(app_path)\", @@@",
       "@@@STEP_LOG_LINE@template.isolate@            \"--args-json\", @@@",
-      "@@@STEP_LOG_LINE@template.isolate@            \"{\\\"test_args\\\": <(test_args),         \\\"xctest\\\": <(xctest),         \\\"test_cases\\\": <(test_cases),         \\\"restart\\\": <(restart)}\", @@@",
+      "@@@STEP_LOG_LINE@template.isolate@            \"{\\\"test_args\\\": <(test_args),         \\\"xctest\\\": <(xctest),         \\\"test_cases\\\": <(test_cases),         \\\"restart\\\": <(restart),         \\\"xcode-parallelization\\\": <(xcode_parallelization)}\", @@@",
       "@@@STEP_LOG_LINE@template.isolate@            \"--out-dir\", @@@",
       "@@@STEP_LOG_LINE@template.isolate@            \"${ISOLATED_OUTDIR}\", @@@",
       "@@@STEP_LOG_LINE@template.isolate@            \"--retries\", @@@",
diff --git a/scripts/slave/recipes/ios/unified_builder_tester.expected/goma_canary.json b/scripts/slave/recipes/ios/unified_builder_tester.expected/goma_canary.json
index 96190c9..d7c4414 100644
--- a/scripts/slave/recipes/ios/unified_builder_tester.expected/goma_canary.json
+++ b/scripts/slave/recipes/ios/unified_builder_tester.expected/goma_canary.json
@@ -650,7 +650,7 @@
       "--json-output",
       "/path/to/tmp/json",
       "copy",
-      "{'conditions': [['OS == \"ios\"', {'variables': {'files': ['<(app_path)/', 'src/ios/build/bots/scripts/'], 'command': ['src/ios/build/bots/scripts/run.py', '--app', '<(app_path)', '--args-json', '{\"test_args\": <(test_args),         \"xctest\": <(xctest),         \"test_cases\": <(test_cases),         \"restart\": <(restart)}', '--out-dir', '${ISOLATED_OUTDIR}', '--retries', '3', '--shards', '<(shards)', '--<(xcode_arg_name)', '<(xcode_version)', '--mac-toolchain-cmd', './mac_toolchain', '--xcode-path', 'Xcode.app', '--wpr-tools-path', '<(wpr_tools_path)', '--replay-path', '<(replay_path)']}}]]}",
+      "{'conditions': [['OS == \"ios\"', {'variables': {'files': ['<(app_path)/', 'src/ios/build/bots/scripts/'], 'command': ['src/ios/build/bots/scripts/run.py', '--app', '<(app_path)', '--args-json', '{\"test_args\": <(test_args),         \"xctest\": <(xctest),         \"test_cases\": <(test_cases),         \"restart\": <(restart),         \"xcode-parallelization\": <(xcode_parallelization)}', '--out-dir', '${ISOLATED_OUTDIR}', '--retries', '3', '--shards', '<(shards)', '--<(xcode_arg_name)', '<(xcode_version)', '--mac-toolchain-cmd', './mac_toolchain', '--xcode-path', 'Xcode.app', '--wpr-tools-path', '<(wpr_tools_path)', '--replay-path', '<(replay_path)']}}]]}",
       "[BUILDER_CACHE]/ios/template.isolate"
     ],
     "cwd": "[BUILDER_CACHE]/ios/src",
@@ -669,7 +669,7 @@
       "@@@STEP_LOG_LINE@template.isolate@            \"--app\", @@@",
       "@@@STEP_LOG_LINE@template.isolate@            \"<(app_path)\", @@@",
       "@@@STEP_LOG_LINE@template.isolate@            \"--args-json\", @@@",
-      "@@@STEP_LOG_LINE@template.isolate@            \"{\\\"test_args\\\": <(test_args),         \\\"xctest\\\": <(xctest),         \\\"test_cases\\\": <(test_cases),         \\\"restart\\\": <(restart)}\", @@@",
+      "@@@STEP_LOG_LINE@template.isolate@            \"{\\\"test_args\\\": <(test_args),         \\\"xctest\\\": <(xctest),         \\\"test_cases\\\": <(test_cases),         \\\"restart\\\": <(restart),         \\\"xcode-parallelization\\\": <(xcode_parallelization)}\", @@@",
       "@@@STEP_LOG_LINE@template.isolate@            \"--out-dir\", @@@",
       "@@@STEP_LOG_LINE@template.isolate@            \"${ISOLATED_OUTDIR}\", @@@",
       "@@@STEP_LOG_LINE@template.isolate@            \"--retries\", @@@",
diff --git a/scripts/slave/recipes/webrtc/chromium_ios.expected/basic_goma_build.json b/scripts/slave/recipes/webrtc/chromium_ios.expected/basic_goma_build.json
index 184c6eb..2188cad 100644
--- a/scripts/slave/recipes/webrtc/chromium_ios.expected/basic_goma_build.json
+++ b/scripts/slave/recipes/webrtc/chromium_ios.expected/basic_goma_build.json
@@ -670,7 +670,7 @@
       "--json-output",
       "/path/to/tmp/json",
       "copy",
-      "{'conditions': [['OS == \"ios\"', {'variables': {'files': ['<(app_path)/', 'src/ios/build/bots/scripts/'], 'command': ['src/ios/build/bots/scripts/run.py', '--app', '<(app_path)', '--args-json', '{\"test_args\": <(test_args),         \"xctest\": <(xctest),         \"test_cases\": <(test_cases),         \"restart\": <(restart)}', '--out-dir', '${ISOLATED_OUTDIR}', '--retries', '3', '--shards', '<(shards)', '--<(xcode_arg_name)', '<(xcode_version)', '--mac-toolchain-cmd', './mac_toolchain', '--xcode-path', 'Xcode.app', '--wpr-tools-path', '<(wpr_tools_path)', '--replay-path', '<(replay_path)']}}]]}",
+      "{'conditions': [['OS == \"ios\"', {'variables': {'files': ['<(app_path)/', 'src/ios/build/bots/scripts/'], 'command': ['src/ios/build/bots/scripts/run.py', '--app', '<(app_path)', '--args-json', '{\"test_args\": <(test_args),         \"xctest\": <(xctest),         \"test_cases\": <(test_cases),         \"restart\": <(restart),         \"xcode-parallelization\": <(xcode_parallelization)}', '--out-dir', '${ISOLATED_OUTDIR}', '--retries', '3', '--shards', '<(shards)', '--<(xcode_arg_name)', '<(xcode_version)', '--mac-toolchain-cmd', './mac_toolchain', '--xcode-path', 'Xcode.app', '--wpr-tools-path', '<(wpr_tools_path)', '--replay-path', '<(replay_path)']}}]]}",
       "[BUILDER_CACHE]/ios/template.isolate"
     ],
     "cwd": "[BUILDER_CACHE]/ios/src",
@@ -689,7 +689,7 @@
       "@@@STEP_LOG_LINE@template.isolate@            \"--app\", @@@",
       "@@@STEP_LOG_LINE@template.isolate@            \"<(app_path)\", @@@",
       "@@@STEP_LOG_LINE@template.isolate@            \"--args-json\", @@@",
-      "@@@STEP_LOG_LINE@template.isolate@            \"{\\\"test_args\\\": <(test_args),         \\\"xctest\\\": <(xctest),         \\\"test_cases\\\": <(test_cases),         \\\"restart\\\": <(restart)}\", @@@",
+      "@@@STEP_LOG_LINE@template.isolate@            \"{\\\"test_args\\\": <(test_args),         \\\"xctest\\\": <(xctest),         \\\"test_cases\\\": <(test_cases),         \\\"restart\\\": <(restart),         \\\"xcode-parallelization\\\": <(xcode_parallelization)}\", @@@",
       "@@@STEP_LOG_LINE@template.isolate@            \"--out-dir\", @@@",
       "@@@STEP_LOG_LINE@template.isolate@            \"${ISOLATED_OUTDIR}\", @@@",
       "@@@STEP_LOG_LINE@template.isolate@            \"--retries\", @@@",
@@ -727,7 +727,7 @@
       "--json-output",
       "/path/to/tmp/json",
       "copy",
-      "{\n  \"args\": [\n    \"--config-variable\", \n    \"OS\", \n    \"ios\", \n    \"--config-variable\", \n    \"app_path\", \n    \"src/out/Release-iphoneos/fake test.app\", \n    \"--config-variable\", \n    \"restart\", \n    \"false\", \n    \"--config-variable\", \n    \"shards\", \n    \"1\", \n    \"--config-variable\", \n    \"test_args\", \n    \"[]\", \n    \"--config-variable\", \n    \"test_cases\", \n    \"[]\", \n    \"--config-variable\", \n    \"xctest\", \n    \"false\", \n    \"--config-variable\", \n    \"use_trusted_cert\", \n    \"false\", \n    \"--isolate\", \n    \"[BUILDER_CACHE]/ios/template.isolate\", \n    \"--isolated\", \n    \"[CLEANUP]/isolate_tmp_1/0.isolated\", \n    \"--path-variable\", \n    \"app_path\", \n    \"src/out/Release-iphoneos/fake test.app\", \n    \"--config-variable\", \n    \"wpr_tools_path\", \n    \"NO_PATH\", \n    \"--config-variable\", \n    \"replay_path\", \n    \"NO_PATH\", \n    \"--config-variable\", \n    \"xcode_arg_name\", \n    \"xcode-build-version\", \n    \"--config-variable\", \n    \"xcode_version\", \n    \"9c40b\"\n  ], \n  \"dir\": \"[BUILDER_CACHE]/ios\", \n  \"version\": 1\n}",
+      "{\n  \"args\": [\n    \"--config-variable\", \n    \"OS\", \n    \"ios\", \n    \"--config-variable\", \n    \"app_path\", \n    \"src/out/Release-iphoneos/fake test.app\", \n    \"--config-variable\", \n    \"restart\", \n    \"false\", \n    \"--config-variable\", \n    \"shards\", \n    \"1\", \n    \"--config-variable\", \n    \"test_args\", \n    \"[]\", \n    \"--config-variable\", \n    \"xcode_parallelization\", \n    \"false\", \n    \"--config-variable\", \n    \"test_cases\", \n    \"[]\", \n    \"--config-variable\", \n    \"xctest\", \n    \"false\", \n    \"--config-variable\", \n    \"use_trusted_cert\", \n    \"false\", \n    \"--isolate\", \n    \"[BUILDER_CACHE]/ios/template.isolate\", \n    \"--isolated\", \n    \"[CLEANUP]/isolate_tmp_1/0.isolated\", \n    \"--path-variable\", \n    \"app_path\", \n    \"src/out/Release-iphoneos/fake test.app\", \n    \"--config-variable\", \n    \"wpr_tools_path\", \n    \"NO_PATH\", \n    \"--config-variable\", \n    \"replay_path\", \n    \"NO_PATH\", \n    \"--config-variable\", \n    \"xcode_arg_name\", \n    \"xcode-build-version\", \n    \"--config-variable\", \n    \"xcode_version\", \n    \"9c40b\"\n  ], \n  \"dir\": \"[BUILDER_CACHE]/ios\", \n  \"version\": 1\n}",
       "[CLEANUP]/isolate_tmp_1/0.isolated.gen.json"
     ],
     "cwd": "[BUILDER_CACHE]/ios/src",
@@ -754,6 +754,9 @@
       "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"test_args\", @@@",
       "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"[]\", @@@",
       "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"--config-variable\", @@@",
+      "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"xcode_parallelization\", @@@",
+      "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"false\", @@@",
+      "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"--config-variable\", @@@",
       "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"test_cases\", @@@",
       "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"[]\", @@@",
       "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"--config-variable\", @@@",
diff --git a/scripts/slave/recipes/webrtc/ios.expected/basic.json b/scripts/slave/recipes/webrtc/ios.expected/basic.json
index ce204dd..4c5300f 100644
--- a/scripts/slave/recipes/webrtc/ios.expected/basic.json
+++ b/scripts/slave/recipes/webrtc/ios.expected/basic.json
@@ -315,7 +315,7 @@
       "--json-output",
       "/path/to/tmp/json",
       "copy",
-      "{'conditions': [['OS == \"ios\"', {'variables': {'files': ['<(app_path)/', 'src/ios/build/bots/scripts/', 'src/out/Debug-iphonesimulator/iossim'], 'command': ['src/ios/build/bots/scripts/run.py', '--app', '<(app_path)', '--args-json', '{\"test_args\": <(test_args),         \"xctest\": <(xctest),         \"test_cases\": <(test_cases),         \"restart\": <(restart)}', '--out-dir', '${ISOLATED_OUTDIR}', '--retries', '3', '--shards', '<(shards)', '--<(xcode_arg_name)', '<(xcode_version)', '--mac-toolchain-cmd', './mac_toolchain', '--xcode-path', 'Xcode.app', '--wpr-tools-path', '<(wpr_tools_path)', '--replay-path', '<(replay_path)', '--iossim', 'src/out/Debug-iphonesimulator/iossim', '--platform', '<(platform)', '--version', '<(version)']}}]]}",
+      "{'conditions': [['OS == \"ios\"', {'variables': {'files': ['<(app_path)/', 'src/ios/build/bots/scripts/', 'src/out/Debug-iphonesimulator/iossim'], 'command': ['src/ios/build/bots/scripts/run.py', '--app', '<(app_path)', '--args-json', '{\"test_args\": <(test_args),         \"xctest\": <(xctest),         \"test_cases\": <(test_cases),         \"restart\": <(restart),         \"xcode-parallelization\": <(xcode_parallelization)}', '--out-dir', '${ISOLATED_OUTDIR}', '--retries', '3', '--shards', '<(shards)', '--<(xcode_arg_name)', '<(xcode_version)', '--mac-toolchain-cmd', './mac_toolchain', '--xcode-path', 'Xcode.app', '--wpr-tools-path', '<(wpr_tools_path)', '--replay-path', '<(replay_path)', '--iossim', 'src/out/Debug-iphonesimulator/iossim', '--platform', '<(platform)', '--version', '<(version)']}}]]}",
       "[BUILDER_CACHE]/ios_debug/template.isolate"
     ],
     "cwd": "[BUILDER_CACHE]/ios_debug/src",
@@ -334,7 +334,7 @@
       "@@@STEP_LOG_LINE@template.isolate@            \"--app\", @@@",
       "@@@STEP_LOG_LINE@template.isolate@            \"<(app_path)\", @@@",
       "@@@STEP_LOG_LINE@template.isolate@            \"--args-json\", @@@",
-      "@@@STEP_LOG_LINE@template.isolate@            \"{\\\"test_args\\\": <(test_args),         \\\"xctest\\\": <(xctest),         \\\"test_cases\\\": <(test_cases),         \\\"restart\\\": <(restart)}\", @@@",
+      "@@@STEP_LOG_LINE@template.isolate@            \"{\\\"test_args\\\": <(test_args),         \\\"xctest\\\": <(xctest),         \\\"test_cases\\\": <(test_cases),         \\\"restart\\\": <(restart),         \\\"xcode-parallelization\\\": <(xcode_parallelization)}\", @@@",
       "@@@STEP_LOG_LINE@template.isolate@            \"--out-dir\", @@@",
       "@@@STEP_LOG_LINE@template.isolate@            \"${ISOLATED_OUTDIR}\", @@@",
       "@@@STEP_LOG_LINE@template.isolate@            \"--retries\", @@@",
@@ -379,7 +379,7 @@
       "--json-output",
       "/path/to/tmp/json",
       "copy",
-      "{\n  \"args\": [\n    \"--config-variable\", \n    \"OS\", \n    \"ios\", \n    \"--config-variable\", \n    \"app_path\", \n    \"src/out/Debug-iphonesimulator/fake tests 1.app\", \n    \"--config-variable\", \n    \"restart\", \n    \"false\", \n    \"--config-variable\", \n    \"shards\", \n    \"1\", \n    \"--config-variable\", \n    \"test_args\", \n    \"[]\", \n    \"--config-variable\", \n    \"test_cases\", \n    \"[]\", \n    \"--config-variable\", \n    \"xctest\", \n    \"false\", \n    \"--config-variable\", \n    \"use_trusted_cert\", \n    \"false\", \n    \"--isolate\", \n    \"[BUILDER_CACHE]/ios_debug/template.isolate\", \n    \"--isolated\", \n    \"[CLEANUP]/isolate_tmp_1/0.isolated\", \n    \"--path-variable\", \n    \"app_path\", \n    \"src/out/Debug-iphonesimulator/fake tests 1.app\", \n    \"--config-variable\", \n    \"wpr_tools_path\", \n    \"NO_PATH\", \n    \"--config-variable\", \n    \"replay_path\", \n    \"NO_PATH\", \n    \"--config-variable\", \n    \"xcode_arg_name\", \n    \"xcode-build-version\", \n    \"--config-variable\", \n    \"xcode_version\", \n    \"9c40b\", \n    \"--config-variable\", \n    \"platform\", \n    \"fake device\", \n    \"--config-variable\", \n    \"version\", \n    \"8.0\"\n  ], \n  \"dir\": \"[BUILDER_CACHE]/ios_debug\", \n  \"version\": 1\n}",
+      "{\n  \"args\": [\n    \"--config-variable\", \n    \"OS\", \n    \"ios\", \n    \"--config-variable\", \n    \"app_path\", \n    \"src/out/Debug-iphonesimulator/fake tests 1.app\", \n    \"--config-variable\", \n    \"restart\", \n    \"false\", \n    \"--config-variable\", \n    \"shards\", \n    \"1\", \n    \"--config-variable\", \n    \"test_args\", \n    \"[]\", \n    \"--config-variable\", \n    \"xcode_parallelization\", \n    \"false\", \n    \"--config-variable\", \n    \"test_cases\", \n    \"[]\", \n    \"--config-variable\", \n    \"xctest\", \n    \"false\", \n    \"--config-variable\", \n    \"use_trusted_cert\", \n    \"false\", \n    \"--isolate\", \n    \"[BUILDER_CACHE]/ios_debug/template.isolate\", \n    \"--isolated\", \n    \"[CLEANUP]/isolate_tmp_1/0.isolated\", \n    \"--path-variable\", \n    \"app_path\", \n    \"src/out/Debug-iphonesimulator/fake tests 1.app\", \n    \"--config-variable\", \n    \"wpr_tools_path\", \n    \"NO_PATH\", \n    \"--config-variable\", \n    \"replay_path\", \n    \"NO_PATH\", \n    \"--config-variable\", \n    \"xcode_arg_name\", \n    \"xcode-build-version\", \n    \"--config-variable\", \n    \"xcode_version\", \n    \"9c40b\", \n    \"--config-variable\", \n    \"platform\", \n    \"fake device\", \n    \"--config-variable\", \n    \"version\", \n    \"8.0\"\n  ], \n  \"dir\": \"[BUILDER_CACHE]/ios_debug\", \n  \"version\": 1\n}",
       "[CLEANUP]/isolate_tmp_1/0.isolated.gen.json"
     ],
     "cwd": "[BUILDER_CACHE]/ios_debug/src",
@@ -406,6 +406,9 @@
       "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"test_args\", @@@",
       "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"[]\", @@@",
       "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"--config-variable\", @@@",
+      "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"xcode_parallelization\", @@@",
+      "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"false\", @@@",
+      "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"--config-variable\", @@@",
       "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"test_cases\", @@@",
       "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"[]\", @@@",
       "@@@STEP_LOG_LINE@0.isolated.gen.json@    \"--config-variable\", @@@",
@@ -454,7 +457,7 @@
       "--json-output",
       "/path/to/tmp/json",
       "copy",
-      "{\n  \"args\": [\n    \"--config-variable\", \n    \"OS\", \n    \"ios\", \n    \"--config-variable\", \n    \"app_path\", \n    \"src/out/Debug-iphonesimulator/fake tests 2.app\", \n    \"--config-variable\", \n    \"restart\", \n    \"false\", \n    \"--config-variable\", \n    \"shards\", \n    \"1\", \n    \"--config-variable\", \n    \"test_args\", \n    \"[]\", \n    \"--config-variable\", \n    \"test_cases\", \n    \"[]\", \n    \"--config-variable\", \n    \"xctest\", \n    \"false\", \n    \"--config-variable\", \n    \"use_trusted_cert\", \n    \"false\", \n    \"--isolate\", \n    \"[BUILDER_CACHE]/ios_debug/template.isolate\", \n    \"--isolated\", \n    \"[CLEANUP]/isolate_tmp_1/1.isolated\", \n    \"--path-variable\", \n    \"app_path\", \n    \"src/out/Debug-iphonesimulator/fake tests 2.app\", \n    \"--config-variable\", \n    \"wpr_tools_path\", \n    \"NO_PATH\", \n    \"--config-variable\", \n    \"replay_path\", \n    \"NO_PATH\", \n    \"--config-variable\", \n    \"xcode_arg_name\", \n    \"xcode-build-version\", \n    \"--config-variable\", \n    \"xcode_version\", \n    \"9c40b\", \n    \"--config-variable\", \n    \"platform\", \n    \"fake device\", \n    \"--config-variable\", \n    \"version\", \n    \"7.1\"\n  ], \n  \"dir\": \"[BUILDER_CACHE]/ios_debug\", \n  \"version\": 1\n}",
+      "{\n  \"args\": [\n    \"--config-variable\", \n    \"OS\", \n    \"ios\", \n    \"--config-variable\", \n    \"app_path\", \n    \"src/out/Debug-iphonesimulator/fake tests 2.app\", \n    \"--config-variable\", \n    \"restart\", \n    \"false\", \n    \"--config-variable\", \n    \"shards\", \n    \"1\", \n    \"--config-variable\", \n    \"test_args\", \n    \"[]\", \n    \"--config-variable\", \n    \"xcode_parallelization\", \n    \"false\", \n    \"--config-variable\", \n    \"test_cases\", \n    \"[]\", \n    \"--config-variable\", \n    \"xctest\", \n    \"false\", \n    \"--config-variable\", \n    \"use_trusted_cert\", \n    \"false\", \n    \"--isolate\", \n    \"[BUILDER_CACHE]/ios_debug/template.isolate\", \n    \"--isolated\", \n    \"[CLEANUP]/isolate_tmp_1/1.isolated\", \n    \"--path-variable\", \n    \"app_path\", \n    \"src/out/Debug-iphonesimulator/fake tests 2.app\", \n    \"--config-variable\", \n    \"wpr_tools_path\", \n    \"NO_PATH\", \n    \"--config-variable\", \n    \"replay_path\", \n    \"NO_PATH\", \n    \"--config-variable\", \n    \"xcode_arg_name\", \n    \"xcode-build-version\", \n    \"--config-variable\", \n    \"xcode_version\", \n    \"9c40b\", \n    \"--config-variable\", \n    \"platform\", \n    \"fake device\", \n    \"--config-variable\", \n    \"version\", \n    \"7.1\"\n  ], \n  \"dir\": \"[BUILDER_CACHE]/ios_debug\", \n  \"version\": 1\n}",
       "[CLEANUP]/isolate_tmp_1/1.isolated.gen.json"
     ],
     "cwd": "[BUILDER_CACHE]/ios_debug/src",
@@ -481,6 +484,9 @@
       "@@@STEP_LOG_LINE@1.isolated.gen.json@    \"test_args\", @@@",
       "@@@STEP_LOG_LINE@1.isolated.gen.json@    \"[]\", @@@",
       "@@@STEP_LOG_LINE@1.isolated.gen.json@    \"--config-variable\", @@@",
+      "@@@STEP_LOG_LINE@1.isolated.gen.json@    \"xcode_parallelization\", @@@",
+      "@@@STEP_LOG_LINE@1.isolated.gen.json@    \"false\", @@@",
+      "@@@STEP_LOG_LINE@1.isolated.gen.json@    \"--config-variable\", @@@",
       "@@@STEP_LOG_LINE@1.isolated.gen.json@    \"test_cases\", @@@",
       "@@@STEP_LOG_LINE@1.isolated.gen.json@    \"[]\", @@@",
       "@@@STEP_LOG_LINE@1.isolated.gen.json@    \"--config-variable\", @@@",
diff --git a/scripts/slave/recipes/webrtc/ios.expected/no_tests.json b/scripts/slave/recipes/webrtc/ios.expected/no_tests.json
index ca1cd58..5b35f07 100644
--- a/scripts/slave/recipes/webrtc/ios.expected/no_tests.json
+++ b/scripts/slave/recipes/webrtc/ios.expected/no_tests.json
@@ -302,7 +302,7 @@
       "--json-output",
       "/path/to/tmp/json",
       "copy",
-      "{'conditions': [['OS == \"ios\"', {'variables': {'files': ['<(app_path)/', 'src/ios/build/bots/scripts/'], 'command': ['src/ios/build/bots/scripts/run.py', '--app', '<(app_path)', '--args-json', '{\"test_args\": <(test_args),         \"xctest\": <(xctest),         \"test_cases\": <(test_cases),         \"restart\": <(restart)}', '--out-dir', '${ISOLATED_OUTDIR}', '--retries', '3', '--shards', '<(shards)', '--<(xcode_arg_name)', '<(xcode_version)', '--mac-toolchain-cmd', './mac_toolchain', '--xcode-path', 'Xcode.app', '--wpr-tools-path', '<(wpr_tools_path)', '--replay-path', '<(replay_path)']}}]]}",
+      "{'conditions': [['OS == \"ios\"', {'variables': {'files': ['<(app_path)/', 'src/ios/build/bots/scripts/'], 'command': ['src/ios/build/bots/scripts/run.py', '--app', '<(app_path)', '--args-json', '{\"test_args\": <(test_args),         \"xctest\": <(xctest),         \"test_cases\": <(test_cases),         \"restart\": <(restart),         \"xcode-parallelization\": <(xcode_parallelization)}', '--out-dir', '${ISOLATED_OUTDIR}', '--retries', '3', '--shards', '<(shards)', '--<(xcode_arg_name)', '<(xcode_version)', '--mac-toolchain-cmd', './mac_toolchain', '--xcode-path', 'Xcode.app', '--wpr-tools-path', '<(wpr_tools_path)', '--replay-path', '<(replay_path)']}}]]}",
       "[BUILDER_CACHE]/ios/template.isolate"
     ],
     "cwd": "[BUILDER_CACHE]/ios/src",
@@ -321,7 +321,7 @@
       "@@@STEP_LOG_LINE@template.isolate@            \"--app\", @@@",
       "@@@STEP_LOG_LINE@template.isolate@            \"<(app_path)\", @@@",
       "@@@STEP_LOG_LINE@template.isolate@            \"--args-json\", @@@",
-      "@@@STEP_LOG_LINE@template.isolate@            \"{\\\"test_args\\\": <(test_args),         \\\"xctest\\\": <(xctest),         \\\"test_cases\\\": <(test_cases),         \\\"restart\\\": <(restart)}\", @@@",
+      "@@@STEP_LOG_LINE@template.isolate@            \"{\\\"test_args\\\": <(test_args),         \\\"xctest\\\": <(xctest),         \\\"test_cases\\\": <(test_cases),         \\\"restart\\\": <(restart),         \\\"xcode-parallelization\\\": <(xcode_parallelization)}\", @@@",
       "@@@STEP_LOG_LINE@template.isolate@            \"--out-dir\", @@@",
       "@@@STEP_LOG_LINE@template.isolate@            \"${ISOLATED_OUTDIR}\", @@@",
       "@@@STEP_LOG_LINE@template.isolate@            \"--retries\", @@@",
diff --git a/scripts/slave/recipes/webrtc/ios.expected/trybot.json b/scripts/slave/recipes/webrtc/ios.expected/trybot.json
index a3a00ff..34991d5 100644
--- a/scripts/slave/recipes/webrtc/ios.expected/trybot.json
+++ b/scripts/slave/recipes/webrtc/ios.expected/trybot.json
@@ -346,7 +346,7 @@
       "--json-output",
       "/path/to/tmp/json",
       "copy",
-      "{'conditions': [['OS == \"ios\"', {'variables': {'files': ['<(app_path)/', 'src/ios/build/bots/scripts/'], 'command': ['src/ios/build/bots/scripts/run.py', '--app', '<(app_path)', '--args-json', '{\"test_args\": <(test_args),         \"xctest\": <(xctest),         \"test_cases\": <(test_cases),         \"restart\": <(restart)}', '--out-dir', '${ISOLATED_OUTDIR}', '--retries', '3', '--shards', '<(shards)', '--<(xcode_arg_name)', '<(xcode_version)', '--mac-toolchain-cmd', './mac_toolchain', '--xcode-path', 'Xcode.app', '--wpr-tools-path', '<(wpr_tools_path)', '--replay-path', '<(replay_path)']}}]]}",
+      "{'conditions': [['OS == \"ios\"', {'variables': {'files': ['<(app_path)/', 'src/ios/build/bots/scripts/'], 'command': ['src/ios/build/bots/scripts/run.py', '--app', '<(app_path)', '--args-json', '{\"test_args\": <(test_args),         \"xctest\": <(xctest),         \"test_cases\": <(test_cases),         \"restart\": <(restart),         \"xcode-parallelization\": <(xcode_parallelization)}', '--out-dir', '${ISOLATED_OUTDIR}', '--retries', '3', '--shards', '<(shards)', '--<(xcode_arg_name)', '<(xcode_version)', '--mac-toolchain-cmd', './mac_toolchain', '--xcode-path', 'Xcode.app', '--wpr-tools-path', '<(wpr_tools_path)', '--replay-path', '<(replay_path)']}}]]}",
       "[BUILDER_CACHE]/ios/template.isolate"
     ],
     "cwd": "[BUILDER_CACHE]/ios/src",
@@ -365,7 +365,7 @@
       "@@@STEP_LOG_LINE@template.isolate@            \"--app\", @@@",
       "@@@STEP_LOG_LINE@template.isolate@            \"<(app_path)\", @@@",
       "@@@STEP_LOG_LINE@template.isolate@            \"--args-json\", @@@",
-      "@@@STEP_LOG_LINE@template.isolate@            \"{\\\"test_args\\\": <(test_args),         \\\"xctest\\\": <(xctest),         \\\"test_cases\\\": <(test_cases),         \\\"restart\\\": <(restart)}\", @@@",
+      "@@@STEP_LOG_LINE@template.isolate@            \"{\\\"test_args\\\": <(test_args),         \\\"xctest\\\": <(xctest),         \\\"test_cases\\\": <(test_cases),         \\\"restart\\\": <(restart),         \\\"xcode-parallelization\\\": <(xcode_parallelization)}\", @@@",
       "@@@STEP_LOG_LINE@template.isolate@            \"--out-dir\", @@@",
       "@@@STEP_LOG_LINE@template.isolate@            \"${ISOLATED_OUTDIR}\", @@@",
       "@@@STEP_LOG_LINE@template.isolate@            \"--retries\", @@@",