Reland "Remove build-side configuration of sizes.py on chromium.chrome bots."

This is a reland of a5101fc464109a6850d630147c0d9f7f41e02cf7

Not to be committed until https://chromium-review.googlesource.com/c/chromium/src/+/1656017

Original change's description:
> Remove build-side configuration of sizes.py on chromium.chrome bots.
>
> Moved to src-side isolated script in crrev.com/c/1604471
>
> Bug: 961548
> Change-Id: I9c737ad58dfb88b98140acfd2747ae53b2b78282
> Reviewed-on: https://chromium-review.googlesource.com/c/chromium/tools/build/+/1605790
> Reviewed-by: Andrew Grieve <agrieve@chromium.org>
> Reviewed-by: Ben Pastene <bpastene@chromium.org>
> Commit-Queue: John Budorick <jbudorick@chromium.org>

Bug: 961548
Change-Id: Ib577d248c37caee5ff5e5aa47c649f5500778846
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/tools/build/+/1655964
Reviewed-by: John Budorick <jbudorick@chromium.org>
Commit-Queue: Ben Pastene <bpastene@chromium.org>
diff --git a/scripts/slave/recipe_modules/chromium_tests/chromium_chrome.py b/scripts/slave/recipe_modules/chromium_tests/chromium_chrome.py
index 3b9a262..f54fef4 100644
--- a/scripts/slave/recipe_modules/chromium_tests/chromium_chrome.py
+++ b/scripts/slave/recipe_modules/chromium_tests/chromium_chrome.py
@@ -77,9 +77,6 @@
       'testing': {
         'platform': 'linux',
       },
-      'tests': {
-        steps.SizesStep(RESULTS_URL, 'linux-google-rel')
-      },
       'isolate_server': 'https://chrome-isolated.appspot.com',
       'swarming_server': 'https://chrome-swarming.appspot.com',
     },
@@ -95,9 +92,6 @@
       'testing': {
         'platform': 'mac',
       },
-      'tests': {
-        steps.SizesStep(RESULTS_URL, 'mac-google-rel')
-      },
       'isolate_server': 'https://chrome-isolated.appspot.com',
       'swarming_server': 'https://chrome-swarming.appspot.com',
     },
@@ -114,9 +108,6 @@
       'testing': {
         'platform': 'win',
       },
-      'tests': {
-        steps.SizesStep(RESULTS_URL, 'win-google-rel')
-      },
       'isolate_server': 'https://chrome-isolated.appspot.com',
       'swarming_server': 'https://chrome-swarming.appspot.com',
     },