diff --git a/DEPS b/DEPS
index 50d96e2..886ccbc 100644
--- a/DEPS
+++ b/DEPS

@@ -44,7 +44,7 @@
   # Three lines of non-changing comments so that
   # the commit queue can handle CLs rolling V8
   # and whatever else without interference from each other.
-  'v8_revision': '133b5e7e3117b9eb1a699aa4591b04394c67aa07',
+  'v8_revision': '975e9a320b6eaf9f12280c35df98e013beb8f041',
   # Three lines of non-changing comments so that
   # the commit queue can handle CLs rolling swarming_client
   # and whatever else without interference from each other.
@@ -96,7 +96,7 @@
   # Three lines of non-changing comments so that
   # the commit queue can handle CLs rolling catapult
   # and whatever else without interference from each other.
-  'catapult_revision': 'cfcae9b972f24e331a8ed0110b5afc96e75919a0',
+  'catapult_revision': '1e05d2f8401ce9b112c2f0e21269f1d7493ce88b',
   # Three lines of non-changing comments so that
   # the commit queue can handle CLs rolling libFuzzer
   # and whatever else without interference from each other.
@@ -120,7 +120,7 @@
 
 deps = {
   'src/breakpad/src':
-    Var('chromium_git') + '/breakpad/breakpad/src.git' + '@' + '3166d8be97c96e567e2c23a496cae4b9194f57fa',
+    Var('chromium_git') + '/breakpad/breakpad/src.git' + '@' + 'efa6d5c1c84e2fcacf6a2eafcf9010f98ef3a4d7',
 
   'src/buildtools':
     Var('chromium_git') + '/chromium/buildtools.git' + '@' +  Var('buildtools_revision'),

diff --git a/base/metrics/histogram.h b/base/metrics/histogram.h
index 63fd243..4500efcf 100644
--- a/base/metrics/histogram.h
+++ b/base/metrics/histogram.h

@@ -81,7 +81,8 @@
 #include "base/macros.h"
 #include "base/metrics/bucket_ranges.h"
 #include "base/metrics/histogram_base.h"
-#if !defined(OS_MACOSX) || defined(OS_IOS)
+#if defined(OS_ANDROID) || defined(OS_CHROMEOS) || defined(OS_IOS) || \
+    defined(OS_WIN)
 // TODO(asvitkine): Migrate callers to to include this directly and remove this.
 // Note: Incrementally migrating platforms as they become clean.
 #include "base/metrics/histogram_macros.h"

diff --git a/chrome/android/java/src/org/chromium/chrome/browser/ntp/cards/CardsVariationParameters.java b/chrome/android/java/src/org/chromium/chrome/browser/ntp/cards/CardsVariationParameters.java
index 0681a57..32bbeed0 100644
--- a/chrome/android/java/src/org/chromium/chrome/browser/ntp/cards/CardsVariationParameters.java
+++ b/chrome/android/java/src/org/chromium/chrome/browser/ntp/cards/CardsVariationParameters.java

@@ -23,7 +23,8 @@
     private static final String TAG = "CardsVariationParams";
 
     // Also defined in ntp_snippets_constants.cc
-    private static final String FIELD_TRIAL_NAME = "NTPSnippets";
+    private static final String FIELD_TRIAL_NAME_MAIN = "NTPSnippets";
+    private static final String FIELD_TRIAL_NAME_VISIBILITY = "NTPSnippetsVisibility";
 
     private static final String PARAM_FAVICON_SERVICE_NAME = "favicons_fetch_from_service";
     private static final String PARAM_FIRST_CARD_OFFSET = "first_card_offset";
@@ -54,37 +55,41 @@
      * with a command line flag). It will return 0 if there is no such field trial.
      */
     public static int getFirstCardOffsetDp() {
-        return getIntValue(PARAM_FIRST_CARD_OFFSET, 0);
+        return getIntValue(FIELD_TRIAL_NAME_VISIBILITY, PARAM_FIRST_CARD_OFFSET, 0);
     }
 
     /**
      * Gets the number of times the first card peeking animation should run.
      */
     public static int getFirstCardAnimationMaxRuns() {
-        return getIntValue(PARAM_FIRST_CARD_ANIMATION_MAX_RUNS, FIRST_CARD_ANIMATION_DEFAULT_VALUE);
+        return getIntValue(FIELD_TRIAL_NAME_VISIBILITY, PARAM_FIRST_CARD_ANIMATION_MAX_RUNS,
+                FIRST_CARD_ANIMATION_DEFAULT_VALUE);
     }
 
     /**
      * @return Whether the NTP should initially be scrolled below the fold.
      */
     public static boolean isScrollBelowTheFoldEnabled() {
-        return Boolean.parseBoolean(getParamValue(PARAM_SCROLL_BELOW_THE_FOLD));
+        return Boolean.parseBoolean(getParamValue(FIELD_TRIAL_NAME_VISIBILITY,
+                PARAM_SCROLL_BELOW_THE_FOLD));
     }
 
     /**
      * @return Whether the NTP should ignore updates for suggestions that have not been seen yet.
      */
     public static boolean ignoreUpdatesForExistingSuggestions() {
-        return Boolean.parseBoolean(getParamValue(PARAM_IGNORE_UPDATES_FOR_EXISTING_SUGGESTIONS));
+        return Boolean.parseBoolean(getParamValue(FIELD_TRIAL_NAME_MAIN,
+                PARAM_IGNORE_UPDATES_FOR_EXISTING_SUGGESTIONS));
     }
 
     public static boolean isFaviconServiceEnabled() {
-        return !PARAM_DISABLED_VALUE.equals(getParamValue(PARAM_FAVICON_SERVICE_NAME));
+        return !PARAM_DISABLED_VALUE.equals(getParamValue(FIELD_TRIAL_NAME_MAIN,
+                PARAM_FAVICON_SERVICE_NAME));
     }
 
-    private static int getIntValue(String paramName, int defaultValue) {
+    private static int getIntValue(String fieldTrialName, String paramName, int defaultValue) {
         // TODO(jkrcal): Get parameter by feature name, not field trial name.
-        String value = getParamValue(paramName);
+        String value = getParamValue(fieldTrialName, paramName);
 
         if (!TextUtils.isEmpty(value)) {
             try {
@@ -97,13 +102,13 @@
         return defaultValue;
     }
 
-    private static String getParamValue(String paramName) {
+    private static String getParamValue(String fieldTrialName, String paramName) {
         if (sTestVariationParams != null) {
             String value = sTestVariationParams.get(paramName);
             if (value == null) return "";
             return value;
         }
 
-        return VariationsAssociatedData.getVariationParamValue(FIELD_TRIAL_NAME, paramName);
+        return VariationsAssociatedData.getVariationParamValue(fieldTrialName, paramName);
     }
 }

diff --git a/chrome/browser/chromeos/policy/active_directory_policy_manager.cc b/chrome/browser/chromeos/policy/active_directory_policy_manager.cc
index a1b91b9..fd35815 100644
--- a/chrome/browser/chromeos/policy/active_directory_policy_manager.cc
+++ b/chrome/browser/chromeos/policy/active_directory_policy_manager.cc

@@ -13,6 +13,7 @@
 #include "chromeos/dbus/dbus_thread_manager.h"
 #include "components/policy/core/common/policy_bundle.h"
 #include "components/policy/core/common/policy_types.h"
+#include "components/policy/policy_constants.h"
 
 namespace policy {
 
@@ -115,6 +116,7 @@
   // TODO(tnagel): Rename CloudPolicyStore to PolicyStore and make the source
   // configurable, then drop PolicyMap::SetSourceForAll().
   policy_map.SetSourceForAll(POLICY_SOURCE_ACTIVE_DIRECTORY);
+  SetEnterpriseUsersDefaults(&policy_map);
   UpdatePolicy(std::move(bundle));
 }
 

diff --git a/chrome/browser/policy/policy_network_browsertest.cc b/chrome/browser/policy/policy_network_browsertest.cc
index 323b6b1..faf7466 100644
--- a/chrome/browser/policy/policy_network_browsertest.cc
+++ b/chrome/browser/policy/policy_network_browsertest.cc

@@ -195,6 +195,8 @@
     command_line->AppendSwitch(
         chromeos::switches::kIgnoreUserProfileMappingForTests);
 #endif
+    // Ensure that QUIC is enabled by default on browser startup.
+    command_line->AppendSwitch(switches::kEnableQuic);
   }
 
   void SetUpInProcessBrowserTestFixture() override {

diff --git a/components/ntp_snippets/features.cc b/components/ntp_snippets/features.cc
index a4cb51d..25935a6df 100644
--- a/components/ntp_snippets/features.cc
+++ b/components/ntp_snippets/features.cc

@@ -19,7 +19,7 @@
     "NTPBookmarkSuggestions", base::FEATURE_ENABLED_BY_DEFAULT};
 
 const base::Feature kRecentOfflineTabSuggestionsFeature{
-    "NTPOfflinePageSuggestions", base::FEATURE_ENABLED_BY_DEFAULT};
+    "NTPOfflinePageSuggestions", base::FEATURE_DISABLED_BY_DEFAULT};
 
 const base::Feature kSaveToOfflineFeature{
     "NTPSaveToOffline", base::FEATURE_ENABLED_BY_DEFAULT};

diff --git a/components/storage_monitor/storage_monitor_linux.cc b/components/storage_monitor/storage_monitor_linux.cc
index 4b3a01f..1bbffa9 100644
--- a/components/storage_monitor/storage_monitor_linux.cc
+++ b/components/storage_monitor/storage_monitor_linux.cc

@@ -15,7 +15,7 @@
 
 #include "base/bind.h"
 #include "base/macros.h"
-#include "base/metrics/histogram.h"
+#include "base/metrics/histogram_macros.h"
 #include "base/process/kill.h"
 #include "base/process/launch.h"
 #include "base/process/process.h"

diff --git a/components/translate/ios/browser/BUILD.gn b/components/translate/ios/browser/BUILD.gn
index d95a2f7..b514e91 100644
--- a/components/translate/ios/browser/BUILD.gn
+++ b/components/translate/ios/browser/BUILD.gn

@@ -5,6 +5,7 @@
 import("//ios/web/js_compile.gni")
 
 source_set("browser") {
+  configs += [ "//build/config/compiler:enable_arc" ]
   sources = [
     "ios_translate_driver.h",
     "ios_translate_driver.mm",

diff --git a/components/translate/ios/browser/ios_translate_driver.mm b/components/translate/ios/browser/ios_translate_driver.mm
index e1851db..2bb266fd 100644
--- a/components/translate/ios/browser/ios_translate_driver.mm
+++ b/components/translate/ios/browser/ios_translate_driver.mm

@@ -29,6 +29,10 @@
 #include "ui/base/window_open_disposition.h"
 #include "url/gurl.h"
 
+#if !defined(__has_feature) || !__has_feature(objc_arc)
+#error "This file requires ARC support."
+#endif
+
 namespace translate {
 
 namespace {

diff --git a/components/translate/ios/browser/js_language_detection_manager.mm b/components/translate/ios/browser/js_language_detection_manager.mm
index aa338475..822b896 100644
--- a/components/translate/ios/browser/js_language_detection_manager.mm
+++ b/components/translate/ios/browser/js_language_detection_manager.mm

@@ -5,10 +5,13 @@
 #import "components/translate/ios/browser/js_language_detection_manager.h"
 
 #include "base/callback.h"
-#include "base/mac/scoped_nsobject.h"
 #include "base/strings/string_util.h"
 #include "base/strings/sys_string_conversions.h"
 
+#if !defined(__has_feature) || !__has_feature(objc_arc)
+#error "This file requires ARC support."
+#endif
+
 namespace language_detection {
 // Note: This should stay in sync with the constant in language_detection.js.
 const size_t kMaxIndexChars = 65535;

diff --git a/components/translate/ios/browser/js_translate_manager.mm b/components/translate/ios/browser/js_translate_manager.mm
index 47f2a4e3..aa5df282 100644
--- a/components/translate/ios/browser/js_translate_manager.mm
+++ b/components/translate/ios/browser/js_translate_manager.mm

@@ -10,14 +10,18 @@
 
 #include "base/logging.h"
 #include "base/mac/bundle_locations.h"
-#import "base/mac/scoped_nsobject.h"
+#import "ios/web/public/web_state/js/crw_js_injection_receiver.h"
+
+#if !defined(__has_feature) || !__has_feature(objc_arc)
+#error "This file requires ARC support."
+#endif
 
 @implementation JsTranslateManager {
-  base::scoped_nsobject<NSString> _translationScript;
+  NSString* _translationScript;
 }
 
 - (NSString*)script {
-  return _translationScript.get();
+  return _translationScript;
 }
 
 - (void)setScript:(NSString*)script {
@@ -43,7 +47,7 @@
                                                    error:&error];
   DCHECK(!error && [content length]);
   script = [script stringByAppendingString:content];
-  _translationScript.reset([script copy]);
+  _translationScript = [script copy];
 }
 
 - (void)injectWaitUntilTranslateReadyScript {
@@ -75,7 +79,9 @@
 
 - (NSString*)injectionContent {
   DCHECK(_translationScript);
-  return _translationScript.autorelease();
+  NSString* translationScript = _translationScript;
+  _translationScript = nil;
+  return translationScript;
 }
 
 @end

diff --git a/components/translate/ios/browser/language_detection_controller.h b/components/translate/ios/browser/language_detection_controller.h
index 70c691e..72a3d5bc 100644
--- a/components/translate/ios/browser/language_detection_controller.h
+++ b/components/translate/ios/browser/language_detection_controller.h

@@ -10,7 +10,6 @@
 
 #include "base/callback_list.h"
 #include "base/gtest_prod_util.h"
-#include "base/mac/scoped_nsobject.h"
 #include "base/macros.h"
 #include "base/memory/weak_ptr.h"
 #include "base/strings/string16.h"
@@ -84,7 +83,7 @@
   void WebStateDestroyed() override;
 
   CallbackList language_detection_callbacks_;
-  base::scoped_nsobject<JsLanguageDetectionManager> js_manager_;
+  JsLanguageDetectionManager* js_manager_;
   BooleanPrefMember translate_enabled_;
   base::WeakPtrFactory<LanguageDetectionController> weak_method_factory_;
 

diff --git a/components/translate/ios/browser/language_detection_controller.mm b/components/translate/ios/browser/language_detection_controller.mm
index 5e631a5..04f387c 100644
--- a/components/translate/ios/browser/language_detection_controller.mm
+++ b/components/translate/ios/browser/language_detection_controller.mm

@@ -18,6 +18,10 @@
 #import "ios/web/public/url_scheme_util.h"
 #include "ios/web/public/web_state/web_state.h"
 
+#if !defined(__has_feature) || !__has_feature(objc_arc)
+#error "This file requires ARC support."
+#endif
+
 namespace translate {
 
 namespace {
@@ -33,7 +37,7 @@
     JsLanguageDetectionManager* manager,
     PrefService* prefs)
     : web::WebStateObserver(web_state),
-      js_manager_([manager retain]),
+      js_manager_(manager),
       weak_method_factory_(this) {
   DCHECK(web::WebStateObserver::web_state());
   DCHECK(js_manager_);

diff --git a/components/translate/ios/browser/translate_controller.h b/components/translate/ios/browser/translate_controller.h
index 6cf848e..c8556e2e 100644
--- a/components/translate/ios/browser/translate_controller.h
+++ b/components/translate/ios/browser/translate_controller.h

@@ -8,7 +8,6 @@
 #include <string>
 
 #include "base/gtest_prod_util.h"
-#include "base/mac/scoped_nsobject.h"
 #include "base/macros.h"
 #include "base/memory/weak_ptr.h"
 #include "ios/web/public/web_state/web_state_observer.h"
@@ -69,7 +68,7 @@
   // Changes the JsTranslateManager used by this TranslateController.
   // Only used for testing.
   void SetJsTranslateManagerForTesting(JsTranslateManager* manager) {
-    js_manager_.reset([manager retain]);
+    js_manager_ = manager;
   }
 
  private:
@@ -95,7 +94,7 @@
   void WebStateDestroyed() override;
 
   Observer* observer_;
-  base::scoped_nsobject<JsTranslateManager> js_manager_;
+  JsTranslateManager* js_manager_;
   base::WeakPtrFactory<TranslateController> weak_method_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(TranslateController);

diff --git a/components/translate/ios/browser/translate_controller.mm b/components/translate/ios/browser/translate_controller.mm
index 6035ba5..ea181c6 100644
--- a/components/translate/ios/browser/translate_controller.mm
+++ b/components/translate/ios/browser/translate_controller.mm

@@ -12,6 +12,10 @@
 #import "components/translate/ios/browser/js_translate_manager.h"
 #include "ios/web/public/web_state/web_state.h"
 
+#if !defined(__has_feature) || !__has_feature(objc_arc)
+#error "This file requires ARC support."
+#endif
+
 namespace translate {
 
 namespace {
@@ -24,7 +28,7 @@
                                          JsTranslateManager* manager)
     : web::WebStateObserver(web_state),
       observer_(nullptr),
-      js_manager_([manager retain]),
+      js_manager_(manager),
       weak_method_factory_(this) {
   DCHECK(js_manager_);
   DCHECK(web::WebStateObserver::web_state());

diff --git a/content/renderer/media/gpu/rtc_video_decoder.cc b/content/renderer/media/gpu/rtc_video_decoder.cc
index 63239737..4a7ebf7 100644
--- a/content/renderer/media/gpu/rtc_video_decoder.cc
+++ b/content/renderer/media/gpu/rtc_video_decoder.cc

@@ -739,7 +739,7 @@
   DCheckGpuVideoAcceleratorFactoriesTaskRunnerIsCurrent();
 
   if (!IsProfileSupported(profile)) {
-    DVLOG(1) << "Unsupported profile " << profile;
+    DVLOG(1) << "Unsupported profile " << GetProfileName(profile);
   } else {
     vda_ = factories_->CreateVideoDecodeAccelerator();
 

diff --git a/content/renderer/render_thread_impl.cc b/content/renderer/render_thread_impl.cc
index 6d11014..d6315802 100644
--- a/content/renderer/render_thread_impl.cc
+++ b/content/renderer/render_thread_impl.cc

@@ -891,6 +891,9 @@
 
   record_purge_suspend_metric_closure_.Reset(base::Bind(
       &RenderThreadImpl::RecordPurgeAndSuspendMetrics, base::Unretained(this)));
+  record_purge_suspend_growth_metric_closure_.Reset(
+      base::Bind(&RenderThreadImpl::RecordPurgeAndSuspendMemoryGrowthMetrics,
+                 base::Unretained(this)));
 
   base::MemoryCoordinatorClientRegistry::GetInstance()->Register(this);
 
@@ -1646,6 +1649,10 @@
     record_purge_suspend_metric_closure_.Reset(
         base::Bind(&RenderThreadImpl::RecordPurgeAndSuspendMetrics,
                    base::Unretained(this)));
+    record_purge_suspend_growth_metric_closure_.Cancel();
+    record_purge_suspend_growth_metric_closure_.Reset(
+        base::Bind(&RenderThreadImpl::RecordPurgeAndSuspendMemoryGrowthMetrics,
+                   base::Unretained(this)));
   }
 }
 
@@ -1760,7 +1767,7 @@
 // we should collect the metrics using memory-infra.
 // TODO(tasak): We should also report a difference between the memory usages
 // before and after purging by using memory-infra.
-void RenderThreadImpl::RecordPurgeAndSuspendMetrics() const {
+void RenderThreadImpl::RecordPurgeAndSuspendMetrics() {
   // If this renderer is resumed, we should not update UMA.
   if (!RendererIsHidden())
     return;
@@ -1781,6 +1788,56 @@
                           memory_metrics.v8_main_thread_isolate_mb);
   UMA_HISTOGRAM_MEMORY_MB("PurgeAndSuspend.Memory.TotalAllocatedMB",
                           memory_metrics.total_allocated_mb);
+  purge_and_suspend_memory_metrics_ = memory_metrics;
+
+  // record how many memory usage increases after purged.
+  GetRendererScheduler()->DefaultTaskRunner()->PostDelayedTask(
+      FROM_HERE, record_purge_suspend_growth_metric_closure_.callback(),
+      base::TimeDelta::FromMinutes(5));
+  GetRendererScheduler()->DefaultTaskRunner()->PostDelayedTask(
+      FROM_HERE, record_purge_suspend_growth_metric_closure_.callback(),
+      base::TimeDelta::FromMinutes(10));
+  GetRendererScheduler()->DefaultTaskRunner()->PostDelayedTask(
+      FROM_HERE, record_purge_suspend_growth_metric_closure_.callback(),
+      base::TimeDelta::FromMinutes(15));
+}
+
+#define GET_MEMORY_GROWTH(current, previous, allocator) \
+  (current.allocator > previous.allocator               \
+       ? current.allocator - previous.allocator         \
+       : 0)
+
+void RenderThreadImpl::RecordPurgeAndSuspendMemoryGrowthMetrics() const {
+  // If this renderer is resumed, we should not update UMA.
+  if (!RendererIsHidden())
+    return;
+
+  RendererMemoryMetrics memory_metrics;
+  GetRendererMemoryMetrics(&memory_metrics);
+  UMA_HISTOGRAM_MEMORY_KB(
+      "PurgeAndSuspend.Experimental.MemoryGrowth.PartitionAllocKB",
+      GET_MEMORY_GROWTH(memory_metrics, purge_and_suspend_memory_metrics_,
+                        partition_alloc_kb));
+  UMA_HISTOGRAM_MEMORY_KB(
+      "PurgeAndSuspend.Experimental.MemoryGrowth.BlinkGCKB",
+      GET_MEMORY_GROWTH(memory_metrics, purge_and_suspend_memory_metrics_,
+                        blink_gc_kb));
+  UMA_HISTOGRAM_MEMORY_MB(
+      "PurgeAndSuspend.Experimental.MemoryGrowth.MallocKB",
+      GET_MEMORY_GROWTH(memory_metrics, purge_and_suspend_memory_metrics_,
+                        malloc_mb) * 1024);
+  UMA_HISTOGRAM_MEMORY_KB(
+      "PurgeAndSuspend.Experimental.MemoryGrowth.DiscardableKB",
+      GET_MEMORY_GROWTH(memory_metrics, purge_and_suspend_memory_metrics_,
+                        discardable_kb));
+  UMA_HISTOGRAM_MEMORY_MB(
+      "PurgeAndSuspend.Experimental.MemoryGrowth.V8MainThreadIsolateKB",
+      GET_MEMORY_GROWTH(memory_metrics, purge_and_suspend_memory_metrics_,
+                        v8_main_thread_isolate_mb) * 1024);
+  UMA_HISTOGRAM_MEMORY_MB(
+      "PurgeAndSuspend.Experimental.MemoryGrowth.TotalAllocatedKB",
+      GET_MEMORY_GROWTH(memory_metrics, purge_and_suspend_memory_metrics_,
+                        total_allocated_mb) * 1024);
 }
 
 void RenderThreadImpl::OnProcessResume() {

diff --git a/content/renderer/render_thread_impl.h b/content/renderer/render_thread_impl.h
index 9c0cfe3..5ec1c93 100644
--- a/content/renderer/render_thread_impl.h
+++ b/content/renderer/render_thread_impl.h

@@ -564,7 +564,8 @@
   void OnRendererHidden();
   void OnRendererVisible();
 
-  void RecordPurgeAndSuspendMetrics() const;
+  void RecordPurgeAndSuspendMetrics();
+  void RecordPurgeAndSuspendMemoryGrowthMetrics() const;
 
   void ReleaseFreeMemory();
 
@@ -763,6 +764,8 @@
       thread_safe_render_message_filter_;
 
   base::CancelableClosure record_purge_suspend_metric_closure_;
+  RendererMemoryMetrics purge_and_suspend_memory_metrics_;
+  base::CancelableClosure record_purge_suspend_growth_metric_closure_;
 
   int32_t client_id_;
 

diff --git a/dbus/exported_object.cc b/dbus/exported_object.cc
index 19d1715..0024df6 100644
--- a/dbus/exported_object.cc
+++ b/dbus/exported_object.cc

@@ -11,7 +11,7 @@
 #include "base/logging.h"
 #include "base/memory/ref_counted.h"
 #include "base/message_loop/message_loop.h"
-#include "base/metrics/histogram.h"
+#include "base/metrics/histogram_macros.h"
 #include "base/threading/thread_restrictions.h"
 #include "base/time/time.h"
 #include "dbus/bus.h"

diff --git a/dbus/object_proxy.cc b/dbus/object_proxy.cc
index 5d9d8e84..15f20c7 100644
--- a/dbus/object_proxy.cc
+++ b/dbus/object_proxy.cc

@@ -10,7 +10,7 @@
 #include "base/bind.h"
 #include "base/logging.h"
 #include "base/message_loop/message_loop.h"
-#include "base/metrics/histogram.h"
+#include "base/metrics/histogram_macros.h"
 #include "base/strings/string_piece.h"
 #include "base/strings/stringprintf.h"
 #include "base/task_runner_util.h"

diff --git a/dbus/signal_sender_verification_unittest.cc b/dbus/signal_sender_verification_unittest.cc
index 320718d..7f5c7906 100644
--- a/dbus/signal_sender_verification_unittest.cc
+++ b/dbus/signal_sender_verification_unittest.cc

@@ -6,7 +6,7 @@
 
 #include "base/bind.h"
 #include "base/message_loop/message_loop.h"
-#include "base/metrics/histogram.h"
+#include "base/metrics/histogram_macros.h"
 #include "base/metrics/histogram_samples.h"
 #include "base/metrics/statistics_recorder.h"
 #include "base/run_loop.h"

diff --git a/device/battery/battery_status_manager_linux.cc b/device/battery/battery_status_manager_linux.cc
index ce52f9f..7d9469e 100644
--- a/device/battery/battery_status_manager_linux.cc
+++ b/device/battery/battery_status_manager_linux.cc

@@ -14,7 +14,7 @@
 #include <vector>
 
 #include "base/macros.h"
-#include "base/metrics/histogram.h"
+#include "base/metrics/histogram_macros.h"
 #include "base/single_thread_task_runner.h"
 #include "base/threading/thread.h"
 #include "base/values.h"

diff --git a/device/bluetooth/bluez/bluetooth_adapter_bluez.cc b/device/bluetooth/bluez/bluetooth_adapter_bluez.cc
index f2a6884..81e189e 100644
--- a/device/bluetooth/bluez/bluetooth_adapter_bluez.cc
+++ b/device/bluetooth/bluez/bluetooth_adapter_bluez.cc

@@ -16,7 +16,7 @@
 #include "base/location.h"
 #include "base/logging.h"
 #include "base/memory/ptr_util.h"
-#include "base/metrics/histogram.h"
+#include "base/metrics/histogram_macros.h"
 #include "base/sequenced_task_runner.h"
 #include "base/single_thread_task_runner.h"
 #include "base/strings/stringprintf.h"

diff --git a/device/bluetooth/bluez/bluetooth_device_bluez.cc b/device/bluetooth/bluez/bluetooth_device_bluez.cc
index 50b54cbb..b060b2f 100644
--- a/device/bluetooth/bluez/bluetooth_device_bluez.cc
+++ b/device/bluetooth/bluez/bluetooth_device_bluez.cc

@@ -12,7 +12,7 @@
 
 #include "base/bind.h"
 #include "base/memory/ptr_util.h"
-#include "base/metrics/histogram.h"
+#include "base/metrics/histogram_macros.h"
 #include "base/strings/string_number_conversions.h"
 #include "base/strings/string_util.h"
 #include "dbus/bus.h"

diff --git a/device/bluetooth/bluez/bluetooth_pairing_bluez.cc b/device/bluetooth/bluez/bluetooth_pairing_bluez.cc
index 611ad01..2602ab9 100644
--- a/device/bluetooth/bluez/bluetooth_pairing_bluez.cc
+++ b/device/bluetooth/bluez/bluetooth_pairing_bluez.cc

@@ -5,7 +5,7 @@
 #include "device/bluetooth/bluez/bluetooth_pairing_bluez.h"
 
 #include "base/logging.h"
-#include "base/metrics/histogram.h"
+#include "base/metrics/histogram_macros.h"
 #include "device/bluetooth/bluetooth_device.h"
 #include "device/bluetooth/bluez/bluetooth_device_bluez.h"
 

diff --git a/headless/lib/embedder_mojo_browsertest.cc b/headless/lib/embedder_mojo_browsertest.cc
index 0ae117b33..92800f1 100644
--- a/headless/lib/embedder_mojo_browsertest.cc
+++ b/headless/lib/embedder_mojo_browsertest.cc

@@ -234,7 +234,7 @@
   }
 
   void ReturnTestResult(const std::string& result) override {
-    FinishAsynchronousTest();
+    DisableClientAndFinishAsynchronousTest();
     FAIL() << "The HTTP page should not have been served and we should not have"
               " recieved a mojo callback!";
   }
@@ -242,6 +242,12 @@
   void OnLoadingFailed(const network::LoadingFailedParams& params) override {
     // The navigation should fail since HTTP requests are blackholed.
     EXPECT_EQ(params.GetErrorText(), "net::ERR_FILE_NOT_FOUND");
+    DisableClientAndFinishAsynchronousTest();
+  }
+
+  void DisableClientAndFinishAsynchronousTest() {
+    devtools_client_->GetNetwork()->Disable();
+    devtools_client_->GetNetwork()->RemoveObserver(this);
     FinishAsynchronousTest();
   }
 };

diff --git a/headless/lib/headless_devtools_client_browsertest.cc b/headless/lib/headless_devtools_client_browsertest.cc
index 4c19d056..6dbd79fa 100644
--- a/headless/lib/headless_devtools_client_browsertest.cc
+++ b/headless/lib/headless_devtools_client_browsertest.cc

@@ -65,6 +65,7 @@
   }
 
   void OnLoadEventFired(const page::LoadEventFiredParams& params) override {
+    devtools_client_->GetPage()->Disable();
     devtools_client_->GetPage()->GetExperimental()->RemoveObserver(this);
     FinishAsynchronousTest();
   }
@@ -174,6 +175,7 @@
                                                               &content_type));
     EXPECT_EQ("text/html", content_type);
 
+    devtools_client_->GetNetwork()->Disable();
     devtools_client_->GetNetwork()->RemoveObserver(this);
     FinishAsynchronousTest();
   }
@@ -208,6 +210,9 @@
 
   void OnFrameStoppedLoading(
       const page::FrameStoppedLoadingParams& params) override {
+    devtools_client_->GetPage()->Disable();
+    devtools_client_->GetPage()->GetExperimental()->RemoveObserver(this);
+
     // Check that a non-experimental command which has no return value can be
     // called with a void() callback.
     devtools_client_->GetPage()->Reload(

diff --git a/headless/lib/headless_web_contents_browsertest.cc b/headless/lib/headless_web_contents_browsertest.cc
index 03097ca1..693e2dc 100644
--- a/headless/lib/headless_web_contents_browsertest.cc
+++ b/headless/lib/headless_web_contents_browsertest.cc

@@ -139,6 +139,9 @@
       const security::SecurityStateChangedParams& params) override {
     EXPECT_EQ(security::SecurityState::NEUTRAL, params.GetSecurityState());
 
+    devtools_client_->GetSecurity()->GetExperimental()->Disable(
+        security::DisableParams::Builder().Build());
+    devtools_client_->GetSecurity()->GetExperimental()->RemoveObserver(this);
     FinishAsynchronousTest();
   }
 };

diff --git a/headless/public/util/dom_tree_extractor_browsertest.cc b/headless/public/util/dom_tree_extractor_browsertest.cc
index 808a10b..22b2379 100644
--- a/headless/public/util/dom_tree_extractor_browsertest.cc
+++ b/headless/public/util/dom_tree_extractor_browsertest.cc

@@ -49,6 +49,7 @@
   }
 
   void OnLoadEventFired(const page::LoadEventFiredParams& params) override {
+    devtools_client_->GetPage()->Disable();
     devtools_client_->GetPage()->RemoveObserver(this);
 
     extractor_.reset(new DomTreeExtractor(devtools_client_.get()));

diff --git a/ios/chrome/DEPS b/ios/chrome/DEPS
index f502fa8..cba7de6 100644
--- a/ios/chrome/DEPS
+++ b/ios/chrome/DEPS

@@ -1,5 +1,6 @@
 include_rules = [
   "+crypto",
+  "+ios/shared/chrome/common",
   "+ios/third_party",
   "+net",
   "+sql",

diff --git a/ios/chrome/app/application_delegate/BUILD.gn b/ios/chrome/app/application_delegate/BUILD.gn
index c29ebfc..cf22cd0 100644
--- a/ios/chrome/app/application_delegate/BUILD.gn
+++ b/ios/chrome/app/application_delegate/BUILD.gn

@@ -73,6 +73,7 @@
 }
 
 source_set("application_delegate_internal") {
+  configs += [ "//build/config/compiler:enable_arc" ]
   sources = [
     "app_navigation.h",
     "app_state.h",

diff --git a/ios/chrome/app/application_delegate/app_state.h b/ios/chrome/app/application_delegate/app_state.h
index 52aff1d..fa1f415 100644
--- a/ios/chrome/app/application_delegate/app_state.h
+++ b/ios/chrome/app/application_delegate/app_state.h

@@ -37,7 +37,7 @@
 
 // Window for the application, it is not set during the initialization method.
 // Set the property before calling methods related to it.
-@property(nonatomic, assign) UIWindow* window;
+@property(nonatomic, weak) UIWindow* window;
 
 // Saves the launchOptions to be used from -newTabFromLaunchOptions. If the
 // application is in background, initialize the browser to basic. If not, launch

diff --git a/ios/chrome/app/application_delegate/app_state.mm b/ios/chrome/app/application_delegate/app_state.mm
index 593da25..2c41052 100644
--- a/ios/chrome/app/application_delegate/app_state.mm
+++ b/ios/chrome/app/application_delegate/app_state.mm

@@ -6,8 +6,8 @@
 
 #include "base/critical_closure.h"
 #import "base/mac/bind_objc_block.h"
-#import "base/mac/scoped_nsobject.h"
 #include "components/metrics/metrics_service.h"
+#import "ios/chrome/app/main_application_delegate.h"
 #import "ios/chrome/app/application_delegate/app_navigation.h"
 #import "ios/chrome/app/application_delegate/browser_launcher.h"
 #import "ios/chrome/app/application_delegate/memory_warning_helper.h"
@@ -40,6 +40,10 @@
 #include "ios/web/net/request_tracker_impl.h"
 #include "net/url_request/url_request_context.h"
 
+#if !defined(__has_feature) || !__has_feature(objc_arc)
+#error "This file requires ARC support."
+#endif
+
 namespace {
 // Helper method to post |closure| on the UI thread.
 void PostTaskOnUIThread(const base::Closure& closure) {
@@ -50,16 +54,16 @@
 
 @interface AppState ()<SafeModeCoordinatorDelegate> {
   // Container for startup information.
-  base::WeakNSProtocol<id<StartupInformation>> _startupInformation;
+  __weak id<StartupInformation> _startupInformation;
   // Browser launcher to launch browser in different states.
-  base::WeakNSProtocol<id<BrowserLauncher>> _browserLauncher;
+  __weak id<BrowserLauncher> _browserLauncher;
   // UIApplicationDelegate for the application.
-  base::WeakNSObject<MainApplicationDelegate> _mainApplicationDelegate;
+  __weak MainApplicationDelegate* _mainApplicationDelegate;
   // Window for the application.
-  base::WeakNSObject<UIWindow> _window;
+  __weak UIWindow* _window;
 
   // Variables backing properties of same name.
-  base::scoped_nsobject<SafeModeCoordinator> _safeModeCoordinator;
+  SafeModeCoordinator* _safeModeCoordinator;
 
   // Start of the current session, used for UMA.
   base::TimeTicks _sessionStartTime;
@@ -69,7 +73,7 @@
   // active.
   BOOL _shouldOpenNTPTabOnActive;
   // Interstitial view used to block any incognito tabs after backgrounding.
-  base::scoped_nsobject<UIView> _incognitoBlocker;
+  UIView* _incognitoBlocker;
   // Whether the application is currently in the background.
   // This is a workaround for rdar://22392526 where
   // -applicationDidEnterBackground: can be called twice.
@@ -81,7 +85,7 @@
 
 // Safe mode coordinator. If this is non-nil, the app is displaying the safe
 // mode UI.
-@property(nonatomic, retain) SafeModeCoordinator* safeModeCoordinator;
+@property(nonatomic, strong) SafeModeCoordinator* safeModeCoordinator;
 
 // Return value for -requiresHandlingAfterLaunchWithOptions that determines if
 // UIKit should make followup delegate calls such as
@@ -115,9 +119,9 @@
     applicationDelegate:(MainApplicationDelegate*)applicationDelegate {
   self = [super init];
   if (self) {
-    _startupInformation.reset(startupInformation);
-    _browserLauncher.reset(browserLauncher);
-    _mainApplicationDelegate.reset(applicationDelegate);
+    _startupInformation = startupInformation;
+    _browserLauncher = browserLauncher;
+    _mainApplicationDelegate = applicationDelegate;
   }
   return self;
 }
@@ -129,11 +133,11 @@
 }
 
 - (void)setSafeModeCoordinator:(SafeModeCoordinator*)safeModeCoordinator {
-  _safeModeCoordinator.reset([safeModeCoordinator retain]);
+  _safeModeCoordinator = safeModeCoordinator;
 }
 
 - (void)setWindow:(UIWindow*)window {
-  _window.reset(window);
+  _window = window;
 }
 
 - (UIWindow*)window {
@@ -192,8 +196,8 @@
     CGRect screenBounds = [[UIScreen mainScreen] bounds];
     CGFloat maxDimension =
         std::max(CGRectGetWidth(screenBounds), CGRectGetHeight(screenBounds));
-    _incognitoBlocker.reset([[UIView alloc]
-        initWithFrame:CGRectMake(0, 0, maxDimension, maxDimension)]);
+    _incognitoBlocker = [[UIView alloc]
+        initWithFrame:CGRectMake(0, 0, maxDimension, maxDimension)];
     InstallBackgroundInView(_incognitoBlocker);
     [_window addSubview:_incognitoBlocker];
   }
@@ -207,12 +211,13 @@
         [[_browserLauncher browserViewInformation] currentBVC]
             .browserState->GetRequestContext();
     _savingCookies = YES;
-    base::Closure criticalClosure = base::MakeCriticalClosure(base::BindBlock(^{
-      DCHECK_CURRENTLY_ON(web::WebThread::UI);
-      _savingCookies = NO;
-    }));
+    base::Closure criticalClosure =
+        base::MakeCriticalClosure(base::BindBlockArc(^{
+          DCHECK_CURRENTLY_ON(web::WebThread::UI);
+          _savingCookies = NO;
+        }));
     web::WebThread::PostTask(
-        web::WebThread::IO, FROM_HERE, base::BindBlock(^{
+        web::WebThread::IO, FROM_HERE, base::BindBlockArc(^{
           net::CookieStoreIOS* store = static_cast<net::CookieStoreIOS*>(
               getter->GetURLRequestContext()->cookie_store());
           // FlushStore() runs its callback on any thread. Jump back to UI.
@@ -259,7 +264,7 @@
   _applicationInBackground = NO;
 
   [_incognitoBlocker removeFromSuperview];
-  _incognitoBlocker.reset();
+  _incognitoBlocker = nil;
 
   breakpad_helper::SetCurrentlyInBackground(false);
 
@@ -315,7 +320,7 @@
 - (void)resumeSessionWithTabOpener:(id<TabOpening>)tabOpener
                        tabSwitcher:(id<TabSwitching>)tabSwitcher {
   [_incognitoBlocker removeFromSuperview];
-  _incognitoBlocker.reset();
+  _incognitoBlocker = nil;
 
   DCHECK([_browserLauncher browserInitializationStage] ==
          INITIALIZATION_STAGE_FOREGROUND);
@@ -443,7 +448,7 @@
   DCHECK([_window rootViewController] == nil);
   if ([SafeModeCoordinator shouldStart]) {
     SafeModeCoordinator* safeModeCoordinator =
-        [[[SafeModeCoordinator alloc] initWithWindow:_window] autorelease];
+        [[SafeModeCoordinator alloc] initWithWindow:_window];
 
     self.safeModeCoordinator = safeModeCoordinator;
     [self.safeModeCoordinator setDelegate:self];

diff --git a/ios/chrome/app/application_delegate/background_activity.mm b/ios/chrome/app/application_delegate/background_activity.mm
index f5c55250..2949ee5 100644
--- a/ios/chrome/app/application_delegate/background_activity.mm
+++ b/ios/chrome/app/application_delegate/background_activity.mm

@@ -4,7 +4,6 @@
 
 #import "ios/chrome/app/application_delegate/background_activity.h"
 
-#import "base/ios/weak_nsobject.h"
 #include "base/metrics/histogram_macros.h"
 #include "base/metrics/user_metrics.h"
 #include "base/metrics/user_metrics_action.h"
@@ -16,6 +15,10 @@
 #import "ios/chrome/browser/metrics/previous_session_info.h"
 #include "url/gurl.h"
 
+#if !defined(__has_feature) || !__has_feature(objc_arc)
+#error "This file requires ARC support."
+#endif
+
 namespace {
 // Key of the UMA Startup.BackgroundFetchTimeInterval histogram.
 const char* const kUMAMobileBackgroundFetchTimeInterval =

diff --git a/ios/chrome/app/application_delegate/metrics_mediator.mm b/ios/chrome/app/application_delegate/metrics_mediator.mm
index 074ff8fc2..0f0385e1 100644
--- a/ios/chrome/app/application_delegate/metrics_mediator.mm
+++ b/ios/chrome/app/application_delegate/metrics_mediator.mm

@@ -4,7 +4,6 @@
 
 #import "ios/chrome/app/application_delegate/metrics_mediator.h"
 
-#include "base/ios/weak_nsobject.h"
 #include "base/mac/bind_objc_block.h"
 #include "base/metrics/user_metrics_action.h"
 #include "base/strings/sys_string_conversions.h"
@@ -31,6 +30,10 @@
 #include "ios/web/public/web_thread.h"
 #include "url/gurl.h"
 
+#if !defined(__has_feature) || !__has_feature(objc_arc)
+#error "This file requires ARC support."
+#endif
+
 namespace {
 // The amount of time (in seconds) between two background fetch calls.
 // TODO(crbug.com/496172): Re-enable background fetch.
@@ -238,18 +241,16 @@
   }
 
   // If metrics are enabled, process the logs. Otherwise, just delete them.
-  base::mac::ScopedBlock<app_group::ProceduralBlockWithData> callback;
+  app_group::ProceduralBlockWithData callback;
   if (enabled) {
-    callback.reset(
-        ^(NSData* log_content) {
-          std::string log(static_cast<const char*>([log_content bytes]),
-                          static_cast<size_t>([log_content length]));
-          web::WebThread::PostTask(web::WebThread::UI, FROM_HERE,
-                                   base::BindBlock(^{
-                                     metrics->PushExternalLog(log);
-                                   }));
-        },
-        base::scoped_policy::RETAIN);
+    callback = [^(NSData* log_content) {
+      std::string log(static_cast<const char*>([log_content bytes]),
+                      static_cast<size_t>([log_content length]));
+      web::WebThread::PostTask(web::WebThread::UI, FROM_HERE,
+                               base::BindBlockArc(^{
+                                 metrics->PushExternalLog(log);
+                               }));
+    } copy];
   }
 
   web::WebThread::PostTask(

diff --git a/ios/chrome/app/application_delegate/url_opener.mm b/ios/chrome/app/application_delegate/url_opener.mm
index 718d470..2f48018 100644
--- a/ios/chrome/app/application_delegate/url_opener.mm
+++ b/ios/chrome/app/application_delegate/url_opener.mm

@@ -6,14 +6,16 @@
 
 #import <Foundation/Foundation.h>
 
-#import "base/ios/weak_nsobject.h"
-#import "base/mac/scoped_nsobject.h"
 #include "base/metrics/histogram_macros.h"
 #import "ios/chrome/app/application_delegate/app_state.h"
 #import "ios/chrome/app/application_delegate/startup_information.h"
 #import "ios/chrome/app/application_delegate/tab_opening.h"
 #include "ios/chrome/app/chrome_app_startup_parameters.h"
 
+#if !defined(__has_feature) || !__has_feature(objc_arc)
+#error "This file requires ARC support."
+#endif
+
 namespace {
 // Key of the UMA Startup.MobileSessionStartFromApps histogram.
 const char* const kUMAMobileSessionStartFromAppsHistogram =
@@ -36,10 +38,9 @@
     startupInformation:(id<StartupInformation>)startupInformation {
   NSString* sourceApplication =
       options[UIApplicationOpenURLOptionsSourceApplicationKey];
-  base::scoped_nsobject<ChromeAppStartupParameters> params(
-      [ChromeAppStartupParameters
-          newChromeAppStartupParametersWithURL:url
-                         fromSourceApplication:sourceApplication]);
+  ChromeAppStartupParameters* params = [ChromeAppStartupParameters
+      newChromeAppStartupParametersWithURL:url
+                     fromSourceApplication:sourceApplication];
 
   MobileSessionCallerApp callerApp = [params callerApp];
 

diff --git a/ios/chrome/app/application_delegate/user_activity_handler.mm b/ios/chrome/app/application_delegate/user_activity_handler.mm
index 6b3b9e8c..5d6a9909 100644
--- a/ios/chrome/app/application_delegate/user_activity_handler.mm
+++ b/ios/chrome/app/application_delegate/user_activity_handler.mm

@@ -9,7 +9,6 @@
 
 #include "base/ios/block_types.h"
 #include "base/ios/ios_util.h"
-#include "base/ios/weak_nsobject.h"
 #include "base/mac/foundation_util.h"
 #include "base/metrics/histogram_macros.h"
 #include "base/metrics/user_metrics_action.h"
@@ -32,6 +31,10 @@
 #include "ui/base/page_transition_types.h"
 #include "url/gurl.h"
 
+#if !defined(__has_feature) || !__has_feature(objc_arc)
+#error "This file requires ARC support."
+#endif
+
 using base::UserMetricsAction;
 
 namespace {
@@ -76,8 +79,8 @@
     // at this time is opening a New Tab Page.
     GURL newTabURL(kChromeUINewTabURL);
     webpageURL = net::NSURLWithGURL(newTabURL);
-    base::scoped_nsobject<AppStartupParameters> startupParams(
-        [[AppStartupParameters alloc] initWithExternalURL:newTabURL]);
+    AppStartupParameters* startupParams =
+        [[AppStartupParameters alloc] initWithExternalURL:newTabURL];
     [startupInformation setStartupParameters:startupParams];
     base::RecordAction(base::UserMetricsAction("IOSLaunchedByUniversalLink"));
   } else if (spotlight::IsSpotlightAvailable() &&
@@ -101,9 +104,8 @@
     if (domain == spotlight::DOMAIN_ACTIONS) {
       webpageURL =
           [NSURL URLWithString:base::SysUTF8ToNSString(kChromeUINewTabURL)];
-      base::scoped_nsobject<AppStartupParameters> startupParams(
-          [[AppStartupParameters alloc]
-              initWithExternalURL:GURL(kChromeUINewTabURL)]);
+      AppStartupParameters* startupParams = [[AppStartupParameters alloc]
+          initWithExternalURL:GURL(kChromeUINewTabURL)];
       BOOL startupParamsSet = spotlight::SetStartupParametersForSpotlightAction(
           itemID, startupParams);
       if (!startupParamsSet) {
@@ -174,8 +176,8 @@
   [startupInformation resetFirstUserActionRecorder];
 
   if (![startupInformation startupParameters]) {
-    base::scoped_nsobject<AppStartupParameters> startupParams(
-        [[AppStartupParameters alloc] initWithExternalURL:webpageGURL]);
+    AppStartupParameters* startupParams =
+        [[AppStartupParameters alloc] initWithExternalURL:webpageGURL];
     [startupInformation setStartupParameters:startupParams];
   }
   return YES;
@@ -256,9 +258,8 @@
   if ([startupInformation isPresentingFirstRunUI])
     return NO;
 
-  base::scoped_nsobject<AppStartupParameters> startupParams(
-      [[AppStartupParameters alloc]
-          initWithExternalURL:GURL(kChromeUINewTabURL)]);
+  AppStartupParameters* startupParams = [[AppStartupParameters alloc]
+      initWithExternalURL:GURL(kChromeUINewTabURL)];
 
   if ([shortcutItem.type isEqualToString:kShortcutNewTab]) {
     base::RecordAction(UserMetricsAction("ApplicationShortcut.NewTabPressed"));

diff --git a/ios/chrome/browser/DEPS b/ios/chrome/browser/DEPS
index 5d7aca8..ceb3045 100644
--- a/ios/chrome/browser/DEPS
+++ b/ios/chrome/browser/DEPS

@@ -93,6 +93,7 @@
   "+ios/net",
   "+ios/public/provider/chrome",
   "+ios/public/provider/components",
+  "+ios/shared/chrome/browser",
   "+ios/web/public",
   "+libxml/xmlwriter.h",
   "+net",

diff --git a/ios/chrome/browser/ui/browser_view_controller.mm b/ios/chrome/browser/ui/browser_view_controller.mm
index 31d9288..af75824e2 100644
--- a/ios/chrome/browser/ui/browser_view_controller.mm
+++ b/ios/chrome/browser/ui/browser_view_controller.mm

@@ -161,7 +161,6 @@
 #include "ios/public/provider/chrome/browser/voice/voice_search_controller.h"
 #include "ios/public/provider/chrome/browser/voice/voice_search_controller_delegate.h"
 #include "ios/public/provider/chrome/browser/voice/voice_search_provider.h"
-#import "ios/third_party/material_components_ios/src/components/Snackbar/src/MaterialSnackbar.h"
 #import "ios/web/navigation/crw_session_controller.h"
 #import "ios/web/navigation/crw_session_entry.h"
 #include "ios/web/navigation/navigation_manager_impl.h"
@@ -288,8 +287,6 @@
 // they are added to the tab model.
 NSString* const kNativeControllerTemporaryKey = @"NativeControllerTemporaryKey";
 
-NSString* const kReadingListSnackbarCategory = @"ReadingListSnackbarCategory";
-
 }  // anonymous namespace
 
 @interface BrowserViewController ()<AppRatingPromptDelegate,
@@ -3504,12 +3501,8 @@
   readingModel->AddEntry(URL, base::SysNSStringToUTF8(title),
                          reading_list::ADDED_VIA_CURRENT_APP);
 
-  NSString* snackBarMessage =
-      l10n_util::GetNSString(IDS_IOS_READING_LIST_SNACKBAR_MESSAGE);
-  MDCSnackbarMessage* message =
-      [MDCSnackbarMessage messageWithText:snackBarMessage];
-  message.category = kReadingListSnackbarCategory;
-  [MDCSnackbarManager showMessage:message];
+  [self showSnackbar:l10n_util::GetNSString(
+                         IDS_IOS_READING_LIST_SNACKBAR_MESSAGE)];
 }
 
 #pragma mark - Keyboard commands management

diff --git a/ios/chrome/browser/ui/contextual_search/BUILD.gn b/ios/chrome/browser/ui/contextual_search/BUILD.gn
index e251d1e3..bc3cd07 100644
--- a/ios/chrome/browser/ui/contextual_search/BUILD.gn
+++ b/ios/chrome/browser/ui/contextual_search/BUILD.gn

@@ -32,6 +32,7 @@
 }
 
 source_set("contextual_search") {
+  configs += [ "//build/config/compiler:enable_arc" ]
   sources = [
     "contextual_search_context.cc",
     "contextual_search_context.h",

diff --git a/ios/chrome/browser/ui/contextual_search/contextual_search_controller.h b/ios/chrome/browser/ui/contextual_search/contextual_search_controller.h
index 5b30b3ce..4576353 100644
--- a/ios/chrome/browser/ui/contextual_search/contextual_search_controller.h
+++ b/ios/chrome/browser/ui/contextual_search/contextual_search_controller.h

@@ -89,7 +89,7 @@
 // the old panel and its views.
 // This property can only be assigned a non-nil value, and can only be assigned
 // a value when its current value is nil.
-@property(nonatomic, assign) ContextualSearchPanelView* panel;
+@property(nonatomic, weak) ContextualSearchPanelView* panel;
 
 // Designated initializer.
 - (instancetype)initWithBrowserState:(ios::ChromeBrowserState*)browserState

diff --git a/ios/chrome/browser/ui/contextual_search/contextual_search_controller.mm b/ios/chrome/browser/ui/contextual_search/contextual_search_controller.mm
index 39bc9d8..9bc3956 100644
--- a/ios/chrome/browser/ui/contextual_search/contextual_search_controller.mm
+++ b/ios/chrome/browser/ui/contextual_search/contextual_search_controller.mm

@@ -8,13 +8,11 @@
 #include <utility>
 
 #include "base/ios/ios_util.h"
-#import "base/ios/weak_nsobject.h"
 #include "base/json/json_reader.h"
 #include "base/logging.h"
 #import "base/mac/bind_objc_block.h"
 #include "base/mac/foundation_util.h"
 #include "base/mac/scoped_block.h"
-#include "base/mac/scoped_nsobject.h"
 #include "base/strings/sys_string_conversions.h"
 #include "base/strings/utf_string_conversions.h"
 #include "base/time/time.h"
@@ -61,6 +59,10 @@
 // Returns |value| clamped so that min <= value <= max
 #define CLAMP(min, value, max) MAX(min, MIN(value, max))
 
+#if !defined(__has_feature) || !__has_feature(objc_arc)
+#error "This file requires ARC support."
+#endif
+
 namespace {
 // command prefix for injected JavaScript.
 const std::string kCommandPrefix = "contextualSearch";
@@ -124,7 +126,7 @@
 
 NSArray* StringValueToRectArray(const std::string& list) {
   NSString* nsList = base::SysUTF8ToNSString(list);
-  NSMutableArray* rectsArray = [[[NSMutableArray alloc] init] autorelease];
+  NSMutableArray* rectsArray = [[NSMutableArray alloc] init];
   NSArray* items = [nsList componentsSeparatedByString:@","];
   for (NSString* item : items) {
     CGRect rect = StringValueToRect(item);
@@ -151,11 +153,11 @@
                                          TouchToSearchPermissionsChangeAudience>
 
 // Controller delegate for the controller to call back to.
-@property(nonatomic, readwrite, assign) id<ContextualSearchControllerDelegate>
+@property(nonatomic, readwrite, weak) id<ContextualSearchControllerDelegate>
     controllerDelegate;
 
 // Permissions interface for this feature. Property is readwrite for testing.
-@property(nonatomic, readwrite, retain)
+@property(nonatomic, readwrite, strong)
     TouchToSearchPermissionsMediator* permissions;
 
 // Synchronous method executed by -asynchronouslyEnableContextualSearch:
@@ -243,13 +245,13 @@
 
 @implementation ContextualSearchController {
   // Permissions interface for this feature.
-  base::scoped_nsobject<TouchToSearchPermissionsMediator> _permissions;
+  TouchToSearchPermissionsMediator* _permissions;
 
   // WebState for the tab this object is attached to.
   web::WebState* _webState;
 
   // Access to the web view from |_webState|.
-  base::scoped_nsprotocol<id<CRWWebViewProxy>> _webViewProxy;
+  id<CRWWebViewProxy> _webViewProxy;
 
   // Observer for |_webState|.
   std::unique_ptr<ContextualSearchWebStateObserver> _webStateObserver;
@@ -258,22 +260,22 @@
   std::unique_ptr<ContextualSearchWebStateObserver> _searchTabWebStateObserver;
 
   // Object that manages find_in_page.js injection into the web view.
-  base::WeakNSObject<JsContextualSearchManager> _contextualSearchJsManager;
+  __weak JsContextualSearchManager* _contextualSearchJsManager;
 
   // Gesture reccognizer for contextual search taps.
-  base::scoped_nsobject<UITapGestureRecognizer> _tapRecognizer;
+  UITapGestureRecognizer* _tapRecognizer;
 
   // Gesture reccognizer for double tap. It is used to prevent |_tapRecognizer|
   // from firing if there is a double tap on the web view. It is disabled when
   // the panel is displayed, since any tap will dismiss the panel in that case.
-  base::scoped_nsobject<UITapGestureRecognizer> _doubleTapRecognizer;
+  UITapGestureRecognizer* _doubleTapRecognizer;
 
   // Gesture recognizer for long-tap copy.
-  base::scoped_nsobject<UILongPressGestureRecognizer> _copyGestureRecognizer;
+  UILongPressGestureRecognizer* _copyGestureRecognizer;
 
   // Gesture recognizer to detect taps outside of the CS interface that would
   // cause it to dismiss.
-  base::scoped_nsobject<WindowGestureObserver> _dismissRecognizer;
+  WindowGestureObserver* _dismissRecognizer;
 
   // Context information retrieved from a search tap.
   std::shared_ptr<ContextualSearchContext> _searchContext;
@@ -286,22 +288,22 @@
 
   // The panel view controlled by this object; it is created externally and
   // owned by its superview. There is no guarantee about its lifetime.
-  base::WeakNSObject<ContextualSearchPanelView> _panelView;
+  __weak ContextualSearchPanelView* _panelView;
 
   // The view containing the highlighting of the search terms.
-  base::WeakNSObject<ContextualSearchHighlighterView> _contextualHighlightView;
+  __weak ContextualSearchHighlighterView* _contextualHighlightView;
 
   // Content view displayed in the peeking section of the panel.
-  base::scoped_nsobject<ContextualSearchHeaderView> _headerView;
+  ContextualSearchHeaderView* _headerView;
 
   // Vertical constraints for layout of the search tab.
-  base::scoped_nsobject<NSArray> _searchTabVerticalConstraints;
+  NSArray* _searchTabVerticalConstraints;
 
   // Container view for the opt-out promo and the search tab view.
-  base::scoped_nsobject<ContextualSearchResultsView> _searchResultsView;
+  ContextualSearchResultsView* _searchResultsView;
 
   // View for the opt-out promo.
-  base::scoped_nsobject<ContextualSearchPromoView> _promoView;
+  ContextualSearchPromoView* _promoView;
 
   // The tab that should be used as the opener for the search tab.
   Tab* _opener;
@@ -377,7 +379,7 @@
   BOOL _preventScrollToShowSelection;
 
   // The time of the last dismiss.
-  base::scoped_nsobject<NSDate> _lastDismiss;
+  NSDate* _lastDismiss;
 }
 
 @synthesize enabled = _enabled;
@@ -388,8 +390,8 @@
                             delegate:(id<ContextualSearchControllerDelegate>)
                                          delegate {
   if ((self = [super init])) {
-    _permissions.reset([[TouchToSearchPermissionsMediator alloc]
-        initWithBrowserState:browserState]);
+    _permissions = [[TouchToSearchPermissionsMediator alloc]
+        initWithBrowserState:browserState];
     [_permissions setAudience:self];
 
     self.controllerDelegate = delegate;
@@ -398,12 +400,12 @@
     // but it will observe and un-observe the web tabs as it changes over time.
     _webStateObserver.reset(new ContextualSearchWebStateObserver(self));
 
-    _copyGestureRecognizer.reset([[UILongPressGestureRecognizer alloc]
+    _copyGestureRecognizer = [[UILongPressGestureRecognizer alloc]
         initWithTarget:self
-                action:@selector(handleLongPressFrom:)]);
+                action:@selector(handleLongPressFrom:)];
 
-    base::WeakNSObject<ContextualSearchController> weakself(self);
-    auto callback = base::BindBlock(
+    __weak ContextualSearchController* weakself = self;
+    auto callback = base::BindBlockArc(
         ^(ContextualSearchDelegate::SearchResolution resolution) {
           [weakself updateForResolvedSearch:resolution];
         });
@@ -418,7 +420,7 @@
 }
 
 - (void)setPermissions:(TouchToSearchPermissionsMediator*)permissions {
-  _permissions.reset(permissions);
+  _permissions = permissions;
 }
 
 - (ContextualSearchPanelView*)panel {
@@ -430,28 +432,28 @@
   DCHECK(panel);
 
   // Save the new panel, set up observation and delegation relationships.
-  _panelView.reset(panel);
+  _panelView = panel;
   [_panelView addMotionObserver:self];
   [_dismissRecognizer setViewToExclude:_panelView];
 
   // Create new subviews.
   NSMutableArray* panelContents = [NSMutableArray arrayWithCapacity:3];
 
-  _headerView.reset([[ContextualSearchHeaderView alloc]
-      initWithHeight:[_panelView configuration].peekingHeight]);
+  _headerView = [[ContextualSearchHeaderView alloc]
+      initWithHeight:[_panelView configuration].peekingHeight];
   [_headerView addGestureRecognizer:_copyGestureRecognizer];
   [_headerView setTapHandler:self];
 
   [panelContents addObject:_headerView];
 
   if (self.permissions.preferenceState == TouchToSearch::UNDECIDED) {
-    _promoView.reset([[ContextualSearchPromoView alloc] initWithFrame:CGRectZero
-                                                             delegate:self]);
+    _promoView = [[ContextualSearchPromoView alloc] initWithFrame:CGRectZero
+                                                         delegate:self];
     [panelContents addObject:_promoView];
   }
 
-  _searchResultsView.reset(
-      [[ContextualSearchResultsView alloc] initWithFrame:CGRectZero]);
+  _searchResultsView =
+      [[ContextualSearchResultsView alloc] initWithFrame:CGRectZero];
   [_searchResultsView setPromoter:self];
   [_searchResultsView setPreloadChecker:self];
   [panelContents addObject:_searchResultsView];
@@ -463,7 +465,7 @@
   // Asynchronously enables contextual search, so that some preferences
   // (UIAccessibilityIsVoiceOverRunning(), for example) have time to synchronize
   // with their own notifications.
-  base::WeakNSObject<ContextualSearchController> weakSelf(self);
+  __weak ContextualSearchController* weakSelf = self;
   dispatch_async(dispatch_get_main_queue(), ^{
     [weakSelf doEnableContextualSearch:enabled];
   });
@@ -486,7 +488,7 @@
   if (_webViewProxy) {
     [[_webViewProxy scrollViewProxy] removeObserver:self];
   }
-  _webViewProxy.reset([webViewProxy retain]);
+  _webViewProxy = webViewProxy;
   if (_webViewProxy) {
     [[_webViewProxy scrollViewProxy] addObserver:self];
   }
@@ -500,9 +502,9 @@
 - (void)setWebState:(web::WebState*)webState {
   [self disconnectWebState];
   if (webState) {
-    _contextualSearchJsManager.reset(static_cast<JsContextualSearchManager*>(
+    _contextualSearchJsManager = static_cast<JsContextualSearchManager*>(
         [webState->GetJSInjectionReceiver()
-            instanceOfClass:[JsContextualSearchManager class]]));
+            instanceOfClass:[JsContextualSearchManager class]]);
     _webState = webState;
     _webStateObserver->ObserveWebState(webState);
     [self updateWebViewProxy:webState->GetWebViewProxy()];
@@ -519,12 +521,11 @@
     if (!_webStateEnabled) {
       DOMAlteringLock::CreateForWebState([self webState]);
 
-      base::WeakNSObject<ContextualSearchController> weakSelf(self);
-      auto callback =
-          base::BindBlock(^bool(const base::DictionaryValue& JSON,
-                                const GURL& originURL, bool userIsInteracting) {
-            base::scoped_nsobject<ContextualSearchController> strongSelf(
-                [weakSelf retain]);
+      __weak ContextualSearchController* weakSelf = self;
+      auto callback = base::BindBlockArc(
+          ^bool(const base::DictionaryValue& JSON, const GURL& originURL,
+                bool userIsInteracting) {
+            ContextualSearchController* strongSelf = weakSelf;
             // |originURL| and |isInteracting| aren't used.
             return [strongSelf handleScriptCommand:JSON];
           });
@@ -532,16 +533,16 @@
 
       // |_doubleTapRecognizer| should be added to the web view before
       // |_tapRecognizer| so |_tapRecognizer| can require it to fail.
-      _doubleTapRecognizer.reset([[UITapGestureRecognizer alloc]
-          initWithTarget:self
-                  action:@selector(ignoreTap:)]);
+      _doubleTapRecognizer =
+          [[UITapGestureRecognizer alloc] initWithTarget:self
+                                                  action:@selector(ignoreTap:)];
       [_doubleTapRecognizer setDelegate:self];
       [_doubleTapRecognizer setNumberOfTapsRequired:2];
       [_webViewProxy addGestureRecognizer:_doubleTapRecognizer];
 
-      _tapRecognizer.reset([[UITapGestureRecognizer alloc]
+      _tapRecognizer = [[UITapGestureRecognizer alloc]
           initWithTarget:self
-                  action:@selector(handleTapFrom:)]);
+                  action:@selector(handleTapFrom:)];
       [_tapRecognizer setDelegate:self];
       [_webViewProxy addGestureRecognizer:_tapRecognizer];
 
@@ -584,7 +585,7 @@
 
 - (void)disconnectWebState {
   if (_webState) {
-    _contextualSearchJsManager.reset();
+    _contextualSearchJsManager = nil;
     _webStateObserver->ObserveWebState(nullptr);
     [self updateWebViewProxy:nil];
     [self disableCurrentWebState];
@@ -595,9 +596,9 @@
   if (!_panelView)
     return;
   if (!_dismissRecognizer) {
-    _dismissRecognizer.reset([[WindowGestureObserver alloc]
+    _dismissRecognizer = [[WindowGestureObserver alloc]
         initWithTarget:self
-                action:@selector(handleWindowGesture:)]);
+                action:@selector(handleWindowGesture:)];
     [_dismissRecognizer setViewToExclude:_panelView];
     [[_panelView window] addGestureRecognizer:_dismissRecognizer];
   }
@@ -616,11 +617,10 @@
 
 - (void)dealloc {
   [self close];
-  [super dealloc];
 }
 
 - (void)handleWindowGesture:(UIGestureRecognizer*)recognizer {
-  DCHECK(recognizer == _dismissRecognizer.get());
+  DCHECK(recognizer == _dismissRecognizer);
   [self dismissPane:ContextualSearch::BASE_PAGE_TAP];
 }
 
@@ -706,7 +706,7 @@
     bool selectionValid;
     if (!JSONCommand.GetBoolean("valid", &selectionValid))
       selectionValid = true;
-    base::WeakNSObject<ContextualSearchController> weakSelf(self);
+    __weak ContextualSearchController* weakSelf = self;
     ProceduralBlockWithBool lockAction = ^(BOOL lockAcquired) {
       if (lockAcquired) {
         [weakSelf handleSelectionChanged:selectedText
@@ -732,7 +732,7 @@
 }
 
 - (void)handleTapFrom:(UIGestureRecognizer*)recognizer {
-  DCHECK(recognizer == _tapRecognizer.get());
+  DCHECK(recognizer == _tapRecognizer);
   // Taps will be triggered by long-presses to make a selection in the webview,
   // as well as 'regular' taps. Long-presses that create a selection will set
   // |_newSelectionDisplaying| as well as populating _selectedText (this happens
@@ -774,7 +774,7 @@
     dispatch_time_t dispatch = dispatch_time(
         DISPATCH_TIME_NOW,
         static_cast<int64_t>(kDOMModificationDelaySeconds * NSEC_PER_SEC));
-    base::WeakNSObject<ContextualSearchController> weakSelf(self);
+    __weak ContextualSearchController* weakSelf = self;
     dispatch_after(dispatch, dispatch_get_main_queue(), ^{
       [weakSelf handleTapAtPoint:tapPoint];
     });
@@ -783,7 +783,7 @@
 }
 
 - (void)handleLongPressFrom:(UIGestureRecognizer*)recognizer {
-  DCHECK(recognizer == _copyGestureRecognizer.get());
+  DCHECK(recognizer == _copyGestureRecognizer);
   if (recognizer.state != UIGestureRecognizerStateEnded)
     return;
 
@@ -827,8 +827,7 @@
   relativeTapPoint.x /= contentSize.width;
   relativeTapPoint.y /= contentSize.height;
 
-  base::WeakNSProtocol<id<CRWWebViewProxy>> weakWebViewProxy(
-      _webViewProxy.get());
+  __weak id<CRWWebViewProxy> weakWebViewProxy = _webViewProxy;
   void (^handler)(NSString*) = ^(NSString* result) {
     [_tapRecognizer setEnabled:YES];
     // If there has been an error in the javascript, return can be nil.
@@ -1022,7 +1021,7 @@
              animated:[_panelView state] != ContextualSearch::DISMISSED];
     if (_resolvedSearch.start_offset != -1 &&
         _resolvedSearch.end_offset != -1) {
-      base::WeakNSObject<ContextualSearchController> weakSelf(self);
+      __weak ContextualSearchController* weakSelf = self;
       [_contextualSearchJsManager
           expandHighlightToStartOffset:_resolvedSearch.start_offset
                              endOffset:_resolvedSearch.end_offset
@@ -1076,7 +1075,7 @@
 - (void)scrollToShowSelection:(CRWWebViewScrollViewProxy*)scrollView {
   if (!scrollView || _preventScrollToShowSelection)
     return;
-  if (!_contextualHighlightView.get()) {
+  if (!_contextualHighlightView) {
     return;
   }
   CGRect highlightBoundingRect = [_contextualHighlightView boundingRect];
@@ -1164,13 +1163,12 @@
   if (![self webState]) {
     return;
   }
-  if (!_contextualHighlightView.get() && [rects count]) {
+  if (!_contextualHighlightView && [rects count]) {
     CGRect frame = [[self webState]->GetWebViewProxy() frame];
     ContextualSearchHighlighterView* highlightView =
-        [[[ContextualSearchHighlighterView alloc] initWithFrame:frame
-                                                       delegate:self]
-            autorelease];
-    _contextualHighlightView.reset(highlightView);
+        [[ContextualSearchHighlighterView alloc] initWithFrame:frame
+                                                      delegate:self];
+    _contextualHighlightView = highlightView;
     [[self webState]->GetWebViewProxy() addSubview:highlightView];
   }
   CGPoint scroll = [[_webViewProxy scrollViewProxy] contentOffset];
@@ -1213,7 +1211,7 @@
   [[_panelView window] removeGestureRecognizer:_dismissRecognizer];
   _delegate.reset();
   [_searchResultsView setActive:NO];
-  _searchResultsView.reset();
+  _searchResultsView = nil;
 }
 
 #pragma mark - Promo view management
@@ -1289,7 +1287,7 @@
 - (void)panelWillPromote:(ContextualSearchPanelView*)panel {
   DCHECK(panel == _panelView);
   [panel removeMotionObserver:self];
-  _panelView.reset();
+  _panelView = nil;
   [self setState:ContextualSearch::DISMISSED
           reason:ContextualSearch::TAB_PROMOTION];
 }
@@ -1423,7 +1421,7 @@
 
 - (void)cleanUpWebStateForDismissWithCompletion:
     (ProceduralBlock)completionHandler {
-  _lastDismiss.reset([[NSDate date] retain]);
+  _lastDismiss = [NSDate date];
   _currentTapCancelled = YES;
   ContextualSearch::PanelState originalState = [_panelView state];
   if (originalState == ContextualSearch::DISMISSED) {
@@ -1448,10 +1446,10 @@
   ContextualSearchDelegate::SearchResolution blank;
   _resolvedSearch = blank;
   if (completionHandler) {
-    base::WeakNSObject<ContextualSearchController> weakSelf(self);
+    __weak ContextualSearchController* weakSelf = self;
     ProceduralBlock javaScriptCompletion = ^{
-      if ([self webState]) {
-        DOMAlteringLock::FromWebState([self webState])->Release(self);
+      if ([weakSelf webState]) {
+        DOMAlteringLock::FromWebState([weakSelf webState])->Release(weakSelf);
         completionHandler();
       }
     };
@@ -1520,9 +1518,8 @@
 }
 
 - (void)promoViewSettingsTapped {
-  base::scoped_nsobject<GenericChromeCommand> command(
-      [[GenericChromeCommand alloc]
-          initWithTag:IDC_SHOW_CONTEXTUAL_SEARCH_SETTINGS]);
+  GenericChromeCommand* command = [[GenericChromeCommand alloc]
+      initWithTag:IDC_SHOW_CONTEXTUAL_SEARCH_SETTINGS];
   UIWindow* main_window = [[UIApplication sharedApplication] keyWindow];
   [main_window chromeExecuteCommand:command];
 }
@@ -1550,8 +1547,8 @@
 - (BOOL)gestureRecognizer:(UIGestureRecognizer*)gestureRecognizer
     shouldRecognizeSimultaneouslyWithGestureRecognizer:
         (UIGestureRecognizer*)otherGestureRecognizer {
-  return gestureRecognizer == _tapRecognizer.get() ||
-         gestureRecognizer == _doubleTapRecognizer.get();
+  return gestureRecognizer == _tapRecognizer ||
+         gestureRecognizer == _doubleTapRecognizer;
 }
 
 #pragma mark - CRWWebViewScrollViewObserver methods
@@ -1623,7 +1620,7 @@
 #pragma mark - ContextualSearchHighlighterDelegate methods
 
 - (void)updateHighlight {
-  base::WeakNSObject<ContextualSearchController> weakSelf(self);
+  __weak ContextualSearchController* weakSelf = self;
   [_contextualSearchJsManager
       highlightRectsWithCompletionHandler:^void(id result, NSError* error) {
         [weakSelf handleHighlightJSResult:result withError:error];

diff --git a/ios/chrome/browser/ui/contextual_search/contextual_search_header_view.h b/ios/chrome/browser/ui/contextual_search/contextual_search_header_view.h
index de0c7d7..ecc31896 100644
--- a/ios/chrome/browser/ui/contextual_search/contextual_search_header_view.h
+++ b/ios/chrome/browser/ui/contextual_search/contextual_search_header_view.h

@@ -12,7 +12,7 @@
 @interface ContextualSearchHeaderView
     : UIView<ContextualSearchPanelMotionObserver>
 
-@property(nonatomic, assign) id<ContextualSearchPanelTapHandler> tapHandler;
+@property(nonatomic, weak) id<ContextualSearchPanelTapHandler> tapHandler;
 
 - (instancetype)initWithHeight:(CGFloat)height NS_DESIGNATED_INITIALIZER;
 

diff --git a/ios/chrome/browser/ui/contextual_search/contextual_search_header_view.mm b/ios/chrome/browser/ui/contextual_search/contextual_search_header_view.mm
index f156b86..5656d85c 100644
--- a/ios/chrome/browser/ui/contextual_search/contextual_search_header_view.mm
+++ b/ios/chrome/browser/ui/contextual_search/contextual_search_header_view.mm

@@ -4,10 +4,8 @@
 
 #import "ios/chrome/browser/ui/contextual_search/contextual_search_header_view.h"
 
-#import "base/ios/weak_nsobject.h"
 #include "base/logging.h"
 #include "base/mac/scoped_cftyperef.h"
-#include "base/mac/scoped_nsobject.h"
 #import "ios/chrome/browser/ui/contextual_search/contextual_search_panel_view.h"
 #import "ios/chrome/browser/ui/uikit_ui_util.h"
 #import "ios/chrome/common/material_timing.h"
@@ -16,6 +14,10 @@
 #include "ios/public/provider/chrome/browser/images/branded_image_provider.h"
 #import "ios/third_party/material_components_ios/src/components/Typography/src/MaterialTypography.h"
 
+#if !defined(__has_feature) || !__has_feature(objc_arc)
+#error "This file requires ARC support."
+#endif
+
 namespace {
 const CGFloat kHorizontalMargin = 24.0;
 const CGFloat kHorizontalLayoutGap = 16.0;
@@ -105,8 +107,8 @@
   // Label showing the text the user tapped on in the web page, and any
   // additional context that will be displayed.
   __unsafe_unretained UILabel* _textLabel;
-  base::WeakNSProtocol<id<ContextualSearchPanelTapHandler>> _tapHandler;
-  base::scoped_nsobject<UIGestureRecognizer> _tapRecognizer;
+  __weak id<ContextualSearchPanelTapHandler> _tapHandler;
+  UIGestureRecognizer* _tapRecognizer;
 }
 
 + (BOOL)requiresConstraintBasedLayout {
@@ -122,27 +124,30 @@
 
   self.translatesAutoresizingMaskIntoConstraints = NO;
   self.backgroundColor = [UIColor whiteColor];
-  _tapRecognizer.reset([[UITapGestureRecognizer alloc] init]);
+  _tapRecognizer = [[UITapGestureRecognizer alloc] init];
   [self addGestureRecognizer:_tapRecognizer];
   [_tapRecognizer addTarget:self action:@selector(panelWasTapped:)];
 
   UIImage* logoImage = ios::GetChromeBrowserProvider()
                            ->GetBrandedImageProvider()
                            ->GetContextualSearchHeaderImage();
-  _logo = [[[IrisingImageView alloc] initWithImage:logoImage] autorelease];
+  IrisingImageView* logo = [[IrisingImageView alloc] initWithImage:logoImage];
+  _logo = logo;
   _logo.translatesAutoresizingMaskIntoConstraints = NO;
   _logo.iris = 0.0;
 
-  _caret = [[[UIImageView alloc]
-      initWithImage:[UIImage imageNamed:@"expand_less"]] autorelease];
+  UIImageView* caret =
+      [[UIImageView alloc] initWithImage:[UIImage imageNamed:@"expand_less"]];
+  _caret = caret;
   _caret.translatesAutoresizingMaskIntoConstraints = NO;
   [_caret setContentHuggingPriority:UILayoutPriorityDefaultHigh
                             forAxis:UILayoutConstraintAxisVertical];
   [_caret setContentHuggingPriority:UILayoutPriorityDefaultHigh
                             forAxis:UILayoutConstraintAxisHorizontal];
 
-  _closeButton =
-      [[[TappableButton alloc] initWithFrame:CGRectZero] autorelease];
+  TappableButton* closeButton =
+      [[TappableButton alloc] initWithFrame:CGRectZero];
+  _closeButton = closeButton;
   _closeButton.translatesAutoresizingMaskIntoConstraints = NO;
   [_closeButton setImage:[UIImage imageNamed:@"card_close_button"]
                 forState:UIControlStateNormal];
@@ -154,7 +159,8 @@
                                   forAxis:UILayoutConstraintAxisHorizontal];
   _closeButton.alpha = 0;
 
-  _textLabel = [[[UILabel alloc] initWithFrame:CGRectZero] autorelease];
+  UILabel* textLabel = [[UILabel alloc] initWithFrame:CGRectZero];
+  _textLabel = textLabel;
   _textLabel.translatesAutoresizingMaskIntoConstraints = NO;
   _textLabel.font = [MDCTypography subheadFont];
   _textLabel.textAlignment = NSTextAlignmentNatural;
@@ -227,7 +233,7 @@
                         action:@selector(closePanel)
               forControlEvents:UIControlEventTouchUpInside];
   }
-  _tapHandler.reset(tapHandler);
+  _tapHandler = tapHandler;
   if (_tapHandler) {
     [_closeButton addTarget:_tapHandler
                      action:@selector(closePanel)
@@ -302,7 +308,7 @@
     followingTextRange:(NSRange)followingTextRange
               animated:(BOOL)animated {
   NSMutableAttributedString* styledText =
-      [[[NSMutableAttributedString alloc] initWithString:text] autorelease];
+      [[NSMutableAttributedString alloc] initWithString:text];
   [styledText addAttribute:NSForegroundColorAttributeName
                      value:[UIColor colorWithWhite:0 alpha:0.71f]
                      range:followingTextRange];

diff --git a/ios/chrome/browser/ui/contextual_search/contextual_search_highlighter_view.mm b/ios/chrome/browser/ui/contextual_search/contextual_search_highlighter_view.mm
index 7461001..bbc9ad8 100644
--- a/ios/chrome/browser/ui/contextual_search/contextual_search_highlighter_view.mm
+++ b/ios/chrome/browser/ui/contextual_search/contextual_search_highlighter_view.mm

@@ -5,9 +5,12 @@
 #import "ios/chrome/browser/ui/contextual_search/contextual_search_highlighter_view.h"
 
 #include "base/logging.h"
-#import "base/mac/scoped_nsobject.h"
 #import "ios/chrome/browser/ui/contextual_search/contextual_search_controller.h"
 
+#if !defined(__has_feature) || !__has_feature(objc_arc)
+#error "This file requires ARC support."
+#endif
+
 @implementation ContextualSearchHighlighterView {
   // Store size of the container view. If size change, text layout will likely
   // change and should be updated.
@@ -18,7 +21,7 @@
   CGFloat _zoom;
   CGFloat _offset;
 
-  __unsafe_unretained id<ContextualSearchHighlighterDelegate> _delegate;
+  __weak id<ContextualSearchHighlighterDelegate> _delegate;
 }
 
 - (instancetype)initWithFrame:(CGRect)frame
@@ -70,7 +73,7 @@
     rect.size.height *= zoom;
     rect.origin.x -= scroll.x;
     rect.origin.y += offset - scroll.y;
-    UIView* view = [[[UIView alloc] initWithFrame:rect] autorelease];
+    UIView* view = [[UIView alloc] initWithFrame:rect];
     [self addSubview:view];
     view.backgroundColor =
         [UIColor colorWithRed:0.67 green:0.88 blue:0.96 alpha:0.6];

diff --git a/ios/chrome/browser/ui/contextual_search/contextual_search_mask_view.mm b/ios/chrome/browser/ui/contextual_search/contextual_search_mask_view.mm
index 23592c6..e9651ec7 100644
--- a/ios/chrome/browser/ui/contextual_search/contextual_search_mask_view.mm
+++ b/ios/chrome/browser/ui/contextual_search/contextual_search_mask_view.mm

@@ -11,6 +11,10 @@
 // Linearly map |delta| in the range [0, 1] to a value in [min, max].
 #define LERP(min, max, delta) (min * (1 - delta) + max * delta)
 
+#if !defined(__has_feature) || !__has_feature(objc_arc)
+#error "This file requires ARC support."
+#endif
+
 namespace {
 const CGFloat kPhoneMaskLimit = 1.0;
 const CGFloat kPadMaskLimit = 0.8;

diff --git a/ios/chrome/browser/ui/contextual_search/contextual_search_metrics.mm b/ios/chrome/browser/ui/contextual_search/contextual_search_metrics.mm
index 0dd4438..f875c3d6 100644
--- a/ios/chrome/browser/ui/contextual_search/contextual_search_metrics.mm
+++ b/ios/chrome/browser/ui/contextual_search/contextual_search_metrics.mm

@@ -10,6 +10,10 @@
 #include "base/metrics/user_metrics.h"
 #include "base/time/time.h"
 
+#if !defined(__has_feature) || !__has_feature(objc_arc)
+#error "This file requires ARC support."
+#endif
+
 using ContextualSearch::PanelState;
 using ContextualSearch::StateChangeReason;
 

diff --git a/ios/chrome/browser/ui/contextual_search/contextual_search_panel_view.h b/ios/chrome/browser/ui/contextual_search/contextual_search_panel_view.h
index 5299df0..e0e82b40 100644
--- a/ios/chrome/browser/ui/contextual_search/contextual_search_panel_view.h
+++ b/ios/chrome/browser/ui/contextual_search/contextual_search_panel_view.h

@@ -21,7 +21,7 @@
 @property(nonatomic, assign) ContextualSearch::PanelState state;
 // Panel configuration, for motion observers that want to do different
 // computations around panel state and position.
-@property(nonatomic, readonly) PanelConfiguration* configuration;
+@property(nonatomic, strong, readonly) PanelConfiguration* configuration;
 
 // Create a panel view. It will need to have a delegate and controller assigned
 // to do anything useful.

diff --git a/ios/chrome/browser/ui/contextual_search/contextual_search_panel_view.mm b/ios/chrome/browser/ui/contextual_search/contextual_search_panel_view.mm
index 1b556aa99..ad94baa 100644
--- a/ios/chrome/browser/ui/contextual_search/contextual_search_panel_view.mm
+++ b/ios/chrome/browser/ui/contextual_search/contextual_search_panel_view.mm

@@ -5,10 +5,7 @@
 #import "ios/chrome/browser/ui/contextual_search/contextual_search_panel_view.h"
 
 #import "base/ios/crb_protocol_observers.h"
-#include "base/ios/weak_nsobject.h"
 #include "base/logging.h"
-#include "base/mac/scoped_block.h"
-#include "base/mac/scoped_nsobject.h"
 #import "ios/chrome/browser/procedural_block_types.h"
 #import "ios/chrome/browser/ui/contextual_search/contextual_search_panel_protocols.h"
 #import "ios/chrome/browser/ui/uikit_ui_util.h"
@@ -16,6 +13,10 @@
 #import "ios/third_party/material_components_ios/src/components/ShadowElevations/src/MaterialShadowElevations.h"
 #import "ios/third_party/material_components_ios/src/components/ShadowLayer/src/MaterialShadowLayer.h"
 
+#if !defined(__has_feature) || !__has_feature(objc_arc)
+#error "This file requires ARC support."
+#endif
+
 namespace {
 
 // Animation timings.
@@ -42,12 +43,13 @@
 // that motion will not cause the panel to move, but if the scrolling reaches
 // the end of its possible range, the gesture will then start dragging the
 // panel.
-@property(nonatomic, assign)
+@property(nonatomic, weak)
     UIView<ContextualSearchPanelScrollSynchronizer>* scrollSynchronizer;
 
 // Private readonly property to be used by weak pointers to |self| for non-
 // retaining access to the underlying ivar in blocks.
-@property(nonatomic, readonly) ContextualSearchPanelObservers* observers;
+@property(nonatomic, strong, readonly)
+    ContextualSearchPanelObservers* observers;
 
 // Utility to generate a PanelMotion struct for the panel's current position.
 - (ContextualSearch::PanelMotion)motion;
@@ -58,26 +60,19 @@
 
   // Constraints that define the size of this view. These will be cleared and
   // regenerated when the horizontal size class changes.
-  base::scoped_nsobject<NSArray> _sizingConstraints;
+  NSArray* _sizingConstraints;
 
   CGPoint _draggingStartPosition;
   CGPoint _scrolledOffset;
-  base::scoped_nsobject<UIPanGestureRecognizer> _dragRecognizer;
-
-  base::scoped_nsobject<ContextualSearchPanelObservers> _observers;
-
-  base::scoped_nsobject<PanelConfiguration> _configuration;
-
-  base::WeakNSProtocol<id<ContextualSearchPanelScrollSynchronizer>>
-      _scrollSynchronizer;
+  UIPanGestureRecognizer* _dragRecognizer;
 
   // Guide that's used to position this view.
-  base::WeakNSObject<UILayoutGuide> _positioningGuide;
+  __weak UILayoutGuide* _positioningGuide;
   // Constraint that sets the size of |_positioningView| so this view is
   // positioned correctly for its state.
-  base::WeakNSObject<NSLayoutConstraint> _positioningViewConstraint;
+  __weak NSLayoutConstraint* _positioningViewConstraint;
   // Other constraints that determine the position of this view.
-  base::scoped_nsobject<NSArray> _positioningConstraints;
+  NSArray* _positioningConstraints;
 
   // Promotion state variables.
   BOOL _resizingForPromotion;
@@ -93,6 +88,9 @@
 }
 
 @synthesize state = _state;
+@synthesize scrollSynchronizer = _scrollSynchronizer;
+@synthesize configuration = _configuration;
+@synthesize observers = _observers;
 
 + (BOOL)requiresConstraintBasedLayout {
   return YES;
@@ -102,27 +100,26 @@
 
 - (instancetype)initWithConfiguration:(PanelConfiguration*)configuration {
   if ((self = [super initWithFrame:CGRectZero])) {
-    _configuration.reset([configuration retain]);
+    _configuration = configuration;
     _state = ContextualSearch::DISMISSED;
 
     self.translatesAutoresizingMaskIntoConstraints = NO;
     self.backgroundColor = [UIColor whiteColor];
     self.accessibilityIdentifier = @"contextualSearchPanel";
 
-    _observers.reset([[ContextualSearchPanelObservers
-        observersWithProtocol:@protocol(ContextualSearchPanelMotionObserver)]
-        retain]);
+    _observers = [ContextualSearchPanelObservers
+        observersWithProtocol:@protocol(ContextualSearchPanelMotionObserver)];
     [self addMotionObserver:self];
 
     // Add gesture recognizer.
-    _dragRecognizer.reset([[UIPanGestureRecognizer alloc]
+    _dragRecognizer = [[UIPanGestureRecognizer alloc]
         initWithTarget:self
-                action:@selector(handleDragFrom:)]);
+                action:@selector(handleDragFrom:)];
     [self addGestureRecognizer:_dragRecognizer];
     [_dragRecognizer setDelegate:self];
 
     // Set up the stack view that holds the panel content
-    _contents = [[[UIStackView alloc] initWithFrame:self.bounds] autorelease];
+    _contents = [[UIStackView alloc] initWithFrame:self.bounds];
     [self addSubview:_contents];
     _contents.translatesAutoresizingMaskIntoConstraints = NO;
     _contents.accessibilityIdentifier = @"panelContents";
@@ -197,16 +194,7 @@
 #pragma mark - Public property getters/setters
 
 - (PanelConfiguration*)configuration {
-  return _configuration.get();
-}
-
-- (void)setScrollSynchronizer:
-    (id<ContextualSearchPanelScrollSynchronizer>)scrollSynchronizer {
-  _scrollSynchronizer.reset(scrollSynchronizer);
-}
-
-- (id<ContextualSearchPanelScrollSynchronizer>)scrollSynchronizer {
-  return _scrollSynchronizer;
+  return _configuration;
 }
 
 - (ContextualSearchPanelObservers*)observers {
@@ -218,11 +206,10 @@
     return;
 
   [_positioningViewConstraint setActive:NO];
-  _positioningViewConstraint.reset();
-  base::WeakNSObject<ContextualSearchPanelView> weakSelf(self);
+  _positioningViewConstraint = nil;
+  __weak ContextualSearchPanelView* weakSelf = self;
   void (^transform)(void) = ^{
-    base::scoped_nsobject<ContextualSearchPanelView> strongSelf(
-        [weakSelf retain]);
+    ContextualSearchPanelView* strongSelf = weakSelf;
     if (strongSelf) {
       [strongSelf setNeedsUpdateConstraints];
       [[strongSelf superview] layoutIfNeeded];
@@ -231,15 +218,13 @@
     }
   };
 
-  base::mac::ScopedBlock<ProceduralBlockWithBool> completion;
+  ProceduralBlockWithBool completion;
   NSTimeInterval animationDuration;
   if (state == ContextualSearch::DISMISSED) {
     animationDuration = kDismissAnimationDuration;
-    completion.reset(
-        ^(BOOL) {
-          [weakSelf setHidden:YES];
-        },
-        base::scoped_policy::RETAIN);
+    completion = [^(BOOL) {
+      [weakSelf setHidden:YES];
+    } copy];
   } else {
     self.hidden = NO;
     animationDuration = kPanelAnimationDuration;
@@ -282,8 +267,7 @@
     if (self.traitCollection.horizontalSizeClass !=
             UIUserInterfaceSizeClassUnspecified &&
         !_sizingConstraints) {
-      _sizingConstraints.reset(
-          [[_configuration constraintsForSizingPanel:self] retain]);
+      _sizingConstraints = [_configuration constraintsForSizingPanel:self];
       [NSLayoutConstraint activateConstraints:_sizingConstraints];
     }
     // Update positioning constraints if they don't exist.
@@ -296,12 +280,12 @@
       ];
       [NSLayoutConstraint activateConstraints:positioningConstraints];
 
-      _positioningConstraints.reset([positioningConstraints retain]);
+      _positioningConstraints = positioningConstraints;
     }
     // Always update the positioning view constraint.
-    _positioningViewConstraint.reset([self.configuration
-        constraintForPositioningGuide:_positioningGuide
-                              atState:self.state]);
+    _positioningViewConstraint =
+        [self.configuration constraintForPositioningGuide:_positioningGuide
+                                                  atState:self.state];
     [_positioningViewConstraint setActive:YES];
   }
   [super updateConstraints];
@@ -312,10 +296,10 @@
     return;
   // Set up the invisible positioning view used to constrain this view's
   // position.
-  UILayoutGuide* positioningGuide = [[[UILayoutGuide alloc] init] autorelease];
+  UILayoutGuide* positioningGuide = [[UILayoutGuide alloc] init];
   positioningGuide.identifier = @"contextualSearchPosition";
   [self.superview addLayoutGuide:positioningGuide];
-  _positioningGuide.reset(positioningGuide);
+  _positioningGuide = positioningGuide;
   [self setNeedsUpdateConstraints];
 }
 
@@ -330,7 +314,7 @@
   [_configuration
       setHorizontalSizeClass:self.traitCollection.horizontalSizeClass];
   [NSLayoutConstraint deactivateConstraints:_sizingConstraints];
-  _sizingConstraints.reset();
+  _sizingConstraints = nil;
   [self setNeedsUpdateConstraints];
 }
 
@@ -360,7 +344,6 @@
   [self removeMotionObserver:self];
   [self removeGestureRecognizer:_dragRecognizer];
   [[_positioningGuide owningView] removeLayoutGuide:_positioningGuide];
-  [super dealloc];
 }
 
 #pragma mark - Gesture recognizer callbacks
@@ -465,12 +448,12 @@
         (UIGestureRecognizer*)otherGestureRecognizer {
   // Allow the drag recognizer and the panel content scroll recognizer to
   // co-recognize.
-  if (gestureRecognizer == _dragRecognizer.get() &&
+  if (gestureRecognizer == _dragRecognizer &&
       otherGestureRecognizer == self.scrollSynchronizer.scrollRecognizer) {
     return YES;
   }
 
-  if (gestureRecognizer == _dragRecognizer.get() &&
+  if (gestureRecognizer == _dragRecognizer &&
       [_dragRecognizer state] == UIGestureRecognizerStateChanged) {
     [gestureRecognizer setEnabled:NO];
   }

diff --git a/ios/chrome/browser/ui/contextual_search/contextual_search_promo_view.mm b/ios/chrome/browser/ui/contextual_search/contextual_search_promo_view.mm
index a4e91b3e..d7209692 100644
--- a/ios/chrome/browser/ui/contextual_search/contextual_search_promo_view.mm
+++ b/ios/chrome/browser/ui/contextual_search/contextual_search_promo_view.mm

@@ -4,8 +4,6 @@
 
 #import "ios/chrome/browser/ui/contextual_search/contextual_search_promo_view.h"
 
-#include "base/ios/weak_nsobject.h"
-#import "base/mac/scoped_nsobject.h"
 #import "ios/chrome/browser/ui/colors/MDCPalette+CrAdditions.h"
 #import "ios/chrome/browser/ui/contextual_search/contextual_search_panel_view.h"
 #include "ios/chrome/browser/ui/uikit_ui_util.h"
@@ -18,6 +16,10 @@
 #include "ui/base/l10n/l10n_util.h"
 #include "url/gurl.h"
 
+#if !defined(__has_feature) || !__has_feature(objc_arc)
+#error "This file requires ARC support."
+#endif
+
 namespace {
 const int kMargin = 16;
 const int kSpaceBelowText = 32;
@@ -38,12 +40,12 @@
 }
 
 @interface ContextualSearchPromoView ()
-@property(nonatomic, assign) id<ContextualSearchPromoViewDelegate> delegate;
+@property(nonatomic, weak) id<ContextualSearchPromoViewDelegate> delegate;
 @end
 
 @implementation ContextualSearchPromoView {
-  base::scoped_nsobject<LabelLinkController> _linkController;
-  base::scoped_nsobject<NSMutableArray> _constraints;
+  LabelLinkController* _linkController;
+  NSMutableArray* _constraints;
 }
 
 @synthesize disabled = _disabled;
@@ -65,13 +67,13 @@
   NSMutableArray* constraints = [NSMutableArray array];
 
   // Initialize text label and its link controller.
-  UILabel* text = [[[UILabel alloc] initWithFrame:CGRectZero] autorelease];
-  base::WeakNSObject<ContextualSearchPromoView> weakSelf(self);
-  _linkController.reset([[LabelLinkController alloc]
+  UILabel* text = [[UILabel alloc] initWithFrame:CGRectZero];
+  __weak ContextualSearchPromoView* weakSelf = self;
+  _linkController = [[LabelLinkController alloc]
       initWithLabel:text
              action:^(const GURL& gurl) {
                [[weakSelf delegate] promoViewSettingsTapped];
-             }]);
+             }];
   [_linkController setLinkColor:UIColorFromRGB(kLinkColorRGB)];
 
   // Label is as wide as the content area of the view.
@@ -87,7 +89,7 @@
 
   // Build style attributes for the label.
   NSMutableParagraphStyle* paragraphStyle =
-      [[[NSMutableParagraphStyle alloc] init] autorelease];
+      [[NSMutableParagraphStyle alloc] init];
   [paragraphStyle setLineBreakMode:NSLineBreakByWordWrapping];
   [paragraphStyle setLineHeightMultiple:kLineSpace];
   NSDictionary* attributes = @{
@@ -99,8 +101,8 @@
   };
 
   // Create and assign attributed text to label.
-  base::scoped_nsobject<NSMutableAttributedString> attributedText(
-      [[NSMutableAttributedString alloc] initWithString:textString]);
+  NSMutableAttributedString* attributedText =
+      [[NSMutableAttributedString alloc] initWithString:textString];
   [attributedText setAttributes:attributes
                           range:NSMakeRange(0, textString.length)];
   text.attributedText = attributedText;
@@ -113,7 +115,7 @@
 
   // Create accept and decline buttons with dimensions defined by the
   // minimum height and width constants.
-  MDCFlatButton* acceptButton = [[[MDCFlatButton alloc] init] autorelease];
+  MDCFlatButton* acceptButton = [[MDCFlatButton alloc] init];
   acceptButton.hasOpaqueBackground = YES;
   acceptButton.inkColor =
       [[[MDCPalette cr_bluePalette] tint300] colorWithAlphaComponent:0.5f];
@@ -136,7 +138,7 @@
   [acceptButton.titleLabel setFont:buttonFont];
 
   UIColor* customTitleColor = [[MDCPalette cr_bluePalette] tint500];
-  MDCButton* declineButton = [[[MDCFlatButton alloc] init] autorelease];
+  MDCButton* declineButton = [[MDCFlatButton alloc] init];
   [constraints addObjectsFromArray:@[
     [declineButton.widthAnchor
         constraintGreaterThanOrEqualToConstant:kButtonMinWidth],
@@ -153,7 +155,7 @@
 
   // Create the divider (a simple colored view) with height defined by
   // |kDividerHeight| and width spanning this view's width.
-  UIView* divider = [[[UIView alloc] initWithFrame:CGRectZero] autorelease];
+  UIView* divider = [[UIView alloc] initWithFrame:CGRectZero];
   divider.backgroundColor = [UIColor colorWithWhite:0.745 alpha:1.0];
   [constraints addObjectsFromArray:@[
     [divider.widthAnchor constraintEqualToAnchor:self.widthAnchor],
@@ -200,7 +202,7 @@
   ]];
 
   [NSLayoutConstraint activateConstraints:constraints];
-  _constraints.reset([constraints retain]);
+  _constraints = constraints;
 
   return self;
 }
@@ -212,7 +214,6 @@
   // constraints are disabled and will not be applied even if some subviews
   // are lingering.
   [NSLayoutConstraint deactivateConstraints:_constraints];
-  [super dealloc];
 }
 
 - (void)setHidden:(BOOL)hidden {

diff --git a/ios/chrome/browser/ui/contextual_search/contextual_search_results_view.h b/ios/chrome/browser/ui/contextual_search/contextual_search_results_view.h
index d63227e..09fd4a3 100644
--- a/ios/chrome/browser/ui/contextual_search/contextual_search_results_view.h
+++ b/ios/chrome/browser/ui/contextual_search/contextual_search_results_view.h

@@ -32,11 +32,11 @@
              ContextualSearchTabProvider>
 @property(nonatomic, assign) BOOL active;
 // The tab that is credited with opening the search results tab.
-@property(nonatomic, assign) Tab* opener;
+@property(nonatomic, weak) Tab* opener;
 // Object that can handle promoting the search results.
-@property(nonatomic, assign) id<ContextualSearchTabPromoter> promoter;
+@property(nonatomic, weak) id<ContextualSearchTabPromoter> promoter;
 // Object that can determine if search results can be preloaded.
-@property(nonatomic, assign) id<ContextualSearchPreloadChecker> preloadChecker;
+@property(nonatomic, weak) id<ContextualSearchPreloadChecker> preloadChecker;
 // YES if the search results have loaded and this view was visible.
 @property(nonatomic, readonly) BOOL contentVisible;
 

diff --git a/ios/chrome/browser/ui/contextual_search/contextual_search_results_view.mm b/ios/chrome/browser/ui/contextual_search/contextual_search_results_view.mm
index 50ba220..92e6652 100644
--- a/ios/chrome/browser/ui/contextual_search/contextual_search_results_view.mm
+++ b/ios/chrome/browser/ui/contextual_search/contextual_search_results_view.mm

@@ -6,8 +6,6 @@
 
 #include <memory>
 
-#import "base/ios/weak_nsobject.h"
-#include "base/mac/scoped_nsobject.h"
 #import "ios/chrome/browser/tabs/tab.h"
 #import "ios/chrome/browser/ui/contextual_search/contextual_search_metrics.h"
 #import "ios/chrome/browser/ui/contextual_search/contextual_search_panel_view.h"
@@ -19,6 +17,10 @@
 #import "ios/web/public/web_state/ui/crw_native_content_provider.h"
 #import "ios/web/web_state/ui/crw_web_controller.h"
 
+#if !defined(__has_feature) || !__has_feature(objc_arc)
+#error "This file requires ARC support."
+#endif
+
 namespace {
 enum SearchResultsViewVisibility { OFFSCREEN, PRELOAD, VISIBLE };
 }
@@ -31,15 +33,13 @@
 @end
 
 @implementation ContextualSearchResultsView {
-  base::WeakNSProtocol<id<ContextualSearchTabPromoter>> _promoter;
-  base::WeakNSProtocol<id<ContextualSearchPreloadChecker>> _preloadChecker;
   std::unique_ptr<ContextualSearchWebStateObserver> _webStateObserver;
 
   // Tab that loads the search results.
-  base::scoped_nsobject<Tab> _tab;
+  Tab* _tab;
 
   // Access to the search tab's web view proxy.
-  base::scoped_nsprotocol<id<CRWWebViewProxy>> _webViewProxy;
+  id<CRWWebViewProxy> _webViewProxy;
 
   BOOL _loaded;
   BOOL _displayed;
@@ -58,6 +58,8 @@
 
 @synthesize active = _active;
 @synthesize opener = _opener;
+@synthesize promoter = _promoter;
+@synthesize preloadChecker = _preloadChecker;
 
 - (instancetype)initWithFrame:(CGRect)frame {
   if ((self = [super initWithFrame:frame])) {
@@ -89,7 +91,7 @@
 }
 
 - (void)setPromoter:(id<ContextualSearchTabPromoter>)promoter {
-  _promoter.reset(promoter);
+  _promoter = promoter;
 }
 
 - (id<ContextualSearchPreloadChecker>)preloadChecker {
@@ -97,7 +99,7 @@
 }
 
 - (void)setPreloadChecker:(id<ContextualSearchPreloadChecker>)preloadChecker {
-  _preloadChecker.reset(preloadChecker);
+  _preloadChecker = preloadChecker;
 }
 
 - (BOOL)contentVisible {
@@ -109,12 +111,12 @@
     // Start watching the embedded Tab's web activity.
     _webStateObserver->ObserveWebState([_tab webState]);
     [[_tab webController] setShouldSuppressDialogs:NO];
-    _webViewProxy.reset([[[_tab webController] webViewProxy] retain]);
+    _webViewProxy = [[_tab webController] webViewProxy];
     [[_webViewProxy scrollViewProxy] setBounces:NO];
   } else {
     // Stop watching the embedded Tab's web activity.
     _webStateObserver->ObserveWebState(nullptr);
-    _webViewProxy.reset(nil);
+    _webViewProxy = nil;
   }
 
   _active = active;
@@ -148,7 +150,7 @@
                                             opener:self.opener
                                   desktopUserAgent:false
                                      configuration:searchTabConfiguration];
-  _tab.reset([tab retain]);
+  _tab = tab;
   // Don't actually start the page load yet -- that happens in -loadTab
 
   _preloadEnabled = preloadEnabled;
@@ -159,7 +161,9 @@
   [self disconnectTab];
   // Allow the search tab to be sized by autoresizing mask again.
   [[_tab view] setTranslatesAutoresizingMaskIntoConstraints:YES];
-  return [_tab.release() autorelease];
+  Tab* tab = _tab;
+  _tab = nil;
+  return tab;
 }
 
 - (void)recordFinishedSearchChained:(BOOL)chained {
@@ -173,7 +177,7 @@
   [[_tab view] removeFromSuperview];
   [[_tab webController] setNativeProvider:nil];
   self.active = NO;
-  _webViewProxy.reset();
+  _webViewProxy = nil;
 }
 
 - (void)cancelLoad {
@@ -181,12 +185,12 @@
   _loadInProgress = NO;
   _loaded = NO;
   [_tab close];
-  _tab.reset();
+  _tab = nil;
 }
 
 - (void)loadPendingSearchIfPossible {
   // If the search tab hasn't been created, or if it's already loaded, no-op.
-  if (!_tab.get() || _loadInProgress || self.active || _visibility == OFFSCREEN)
+  if (!_tab || _loadInProgress || self.active || _visibility == OFFSCREEN)
     return;
 
   // If this view is in a position where loading would be "preloading", check
@@ -199,7 +203,7 @@
 }
 
 - (void)loadTab {
-  DCHECK(_tab.get());
+  DCHECK(_tab);
   // Start observing the search tab.
   self.active = YES;
   // TODO(crbug.com/546223): See if |_waitingForInitialSearchTabLoad| and

diff --git a/ios/chrome/browser/ui/contextual_search/contextual_search_web_state_observer.mm b/ios/chrome/browser/ui/contextual_search/contextual_search_web_state_observer.mm
index 6b4595d6..ad23ed5 100644
--- a/ios/chrome/browser/ui/contextual_search/contextual_search_web_state_observer.mm
+++ b/ios/chrome/browser/ui/contextual_search/contextual_search_web_state_observer.mm

@@ -4,6 +4,10 @@
 
 #include "ios/chrome/browser/ui/contextual_search/contextual_search_web_state_observer.h"
 
+#if !defined(__has_feature) || !__has_feature(objc_arc)
+#error "This file requires ARC support."
+#endif
+
 ContextualSearchWebStateObserver::ContextualSearchWebStateObserver(
     id<ContextualSearchWebStateDelegate> delegate)
     : web::WebStateObserver(), delegate_(delegate), loaded_(false) {}

diff --git a/ios/chrome/browser/ui/contextual_search/js_contextual_search_manager.mm b/ios/chrome/browser/ui/contextual_search/js_contextual_search_manager.mm
index 872571d..ec37c55f 100644
--- a/ios/chrome/browser/ui/contextual_search/js_contextual_search_manager.mm
+++ b/ios/chrome/browser/ui/contextual_search/js_contextual_search_manager.mm

@@ -7,10 +7,13 @@
 #include "base/ios/ios_util.h"
 #include "base/mac/foundation_util.h"
 #include "base/mac/scoped_block.h"
-#include "base/mac/scoped_nsobject.h"
 #include "base/strings/string_util.h"
 #include "base/strings/sys_string_conversions.h"
 
+#if !defined(__has_feature) || !__has_feature(objc_arc)
+#error "This file requires ARC support."
+#endif
+
 static NSString* const kEnableSelectionChangeListener =
     @"__gCrWeb.contextualSearch.enableSelectionChangeListener(%@);";
 

diff --git a/ios/chrome/browser/ui/contextual_search/panel_configuration.mm b/ios/chrome/browser/ui/contextual_search/panel_configuration.mm
index 7e836d9..54675748 100644
--- a/ios/chrome/browser/ui/contextual_search/panel_configuration.mm
+++ b/ios/chrome/browser/ui/contextual_search/panel_configuration.mm

@@ -5,7 +5,10 @@
 #include "ios/chrome/browser/ui/contextual_search/panel_configuration.h"
 
 #include "base/logging.h"
-#include "base/mac/scoped_nsobject.h"
+
+#if !defined(__has_feature) || !__has_feature(objc_arc)
+#error "This file requires ARC support."
+#endif
 
 namespace {
 // Amount of tab that a previewing pane leaves visible, expressed as a fraction.
@@ -43,7 +46,7 @@
 + (instancetype)configurationForContainerSize:(CGSize)containerSize
                           horizontalSizeClass:
                               (UIUserInterfaceSizeClass)horizontalSizeClass {
-  PanelConfiguration* config = [[[self alloc] init] autorelease];
+  PanelConfiguration* config = [[self alloc] init];
   config.containerSize = containerSize;
   config.horizontalSizeClass = horizontalSizeClass;
   return config;

diff --git a/ios/chrome/browser/ui/contextual_search/touch_to_search_permissions_mediator.h b/ios/chrome/browser/ui/contextual_search/touch_to_search_permissions_mediator.h
index 44ebdbac..af85360f 100644
--- a/ios/chrome/browser/ui/contextual_search/touch_to_search_permissions_mediator.h
+++ b/ios/chrome/browser/ui/contextual_search/touch_to_search_permissions_mediator.h

@@ -58,7 +58,7 @@
     TouchToSearch::TouchToSearchPreferenceState preferenceState;
 
 // Current audience object.
-@property(nonatomic, assign)
+@property(nonatomic, weak)
     NSObject<TouchToSearchPermissionsChangeAudience>* audience;
 
 // YES if, given the current permissions state, touch-to-search can be enabled.

diff --git a/ios/chrome/browser/ui/contextual_search/touch_to_search_permissions_mediator.mm b/ios/chrome/browser/ui/contextual_search/touch_to_search_permissions_mediator.mm
index ce48928e..7a2598c6 100644
--- a/ios/chrome/browser/ui/contextual_search/touch_to_search_permissions_mediator.mm
+++ b/ios/chrome/browser/ui/contextual_search/touch_to_search_permissions_mediator.mm

@@ -7,7 +7,6 @@
 #import <UIKit/UIKit.h>
 
 #include "base/command_line.h"
-#import "base/ios/weak_nsobject.h"
 #include "base/logging.h"
 #include "components/prefs/pref_change_registrar.h"
 #include "components/prefs/pref_service.h"
@@ -22,6 +21,10 @@
 #include "ios/chrome/browser/sync/sync_setup_service_factory.h"
 #include "net/base/network_change_notifier.h"
 
+#if !defined(__has_feature) || !__has_feature(objc_arc)
+#error "This file requires ARC support."
+#endif
+
 namespace {
 // Maps pref string values to state enum.
 const struct {
@@ -37,8 +40,7 @@
 @interface TouchToSearchPermissionsMediator ()<PrefObserverDelegate> {
   ios::ChromeBrowserState* _browserState;
   SyncSetupService* _syncService;
-  base::WeakNSProtocol<NSObject<TouchToSearchPermissionsChangeAudience>*>
-      _audience;
+  __weak NSObject<TouchToSearchPermissionsChangeAudience>* _audience;
   // Pref observer to track changes to the touch-to-search and search engine
   // prefs.
   std::unique_ptr<PrefObserverBridge> _prefObserverBridge;
@@ -89,7 +91,6 @@
   if ((self = [super init])) {
     if (browserState && browserState->IsOffTheRecord()) {
       // Discard the allocated object and return a nil object.
-      [self release];
       return nil;
     }
     [self setUpBrowserState:browserState];
@@ -105,7 +106,6 @@
 - (void)dealloc {
   // Set audience to nil to stop observation.
   self.audience = nil;
-  [super dealloc];
 }
 
 - (void)setUpBrowserState:(ios::ChromeBrowserState*)browserState {
@@ -146,7 +146,7 @@
 - (void)setAudience:
     (NSObject<TouchToSearchPermissionsChangeAudience>*)audience {
   [self stopObserving];
-  _audience.reset(audience);
+  _audience = audience;
   [self startObserving];
 }
 
@@ -270,8 +270,8 @@
   if (self.audience) {
     if ([self.audience
             respondsToSelector:@selector(touchToSearchPermissionsUpdated)]) {
-      base::WeakNSProtocol<NSObject<TouchToSearchPermissionsChangeAudience>*>
-          audience(self.audience);
+      __weak NSObject<TouchToSearchPermissionsChangeAudience>* audience =
+          self.audience;
       dispatch_async(dispatch_get_main_queue(), ^{
         [audience touchToSearchPermissionsUpdated];
       });

diff --git a/ios/chrome/browser/ui/contextual_search/window_gesture_observer.h b/ios/chrome/browser/ui/contextual_search/window_gesture_observer.h
index 0bd2b1b..f0228c1 100644
--- a/ios/chrome/browser/ui/contextual_search/window_gesture_observer.h
+++ b/ios/chrome/browser/ui/contextual_search/window_gesture_observer.h

@@ -33,8 +33,8 @@
 
 @interface WindowGestureObserver : UIGestureRecognizer
 
-@property(nonatomic, assign) UIView* viewToExclude;
-@property(nonatomic, readonly) UIView* touchedView;
+@property(nonatomic, weak) UIView* viewToExclude;
+@property(nonatomic, weak, readonly) UIView* touchedView;
 @end
 
 #endif  // IOS_CHROME_BROWSER_UI_CONTEXTUAL_SEARCH_WINDOW_GESTURE_OBSERVER_H_

diff --git a/ios/chrome/browser/ui/contextual_search/window_gesture_observer.mm b/ios/chrome/browser/ui/contextual_search/window_gesture_observer.mm
index 0ef504e8..9a89c05 100644
--- a/ios/chrome/browser/ui/contextual_search/window_gesture_observer.mm
+++ b/ios/chrome/browser/ui/contextual_search/window_gesture_observer.mm

@@ -4,6 +4,10 @@
 
 #include "ios/chrome/browser/ui/contextual_search/window_gesture_observer.h"
 
+#if !defined(__has_feature) || !__has_feature(objc_arc)
+#error "This file requires ARC support."
+#endif
+
 @implementation WindowGestureObserver {
   NSObject* _target;
   SEL _action;
@@ -42,11 +46,16 @@
     if (![[touch view] isDescendantOfView:_viewToExclude]) {
       _touchedView = [touch view];
       dispatch_async(dispatch_get_main_queue(), ^{
+
+#pragma clang diagnostic push
+#pragma clang diagnostic ignored "-Warc-performSelector-leaks"
         if (_actionPassesSelf) {
           [_target performSelector:_action withObject:self];
         } else {
           [_target performSelector:_action];
         }
+#pragma clang diagnostic pop
+
       });
       // Only invoke from the first qualifying touch.
       break;

diff --git a/ios/chrome/browser/ui/reading_list/reading_list_view_controller.mm b/ios/chrome/browser/ui/reading_list/reading_list_view_controller.mm
index 808e0ac..f4ca8cb 100644
--- a/ios/chrome/browser/ui/reading_list/reading_list_view_controller.mm
+++ b/ios/chrome/browser/ui/reading_list/reading_list_view_controller.mm

@@ -243,13 +243,6 @@
     [audience setCollectionHasItems:self.readingListModel->size() > 0];
 }
 
-#pragma mark UIAccessibilityAction
-
-- (BOOL)accessibilityPerformEscape {
-  [self dismiss];
-  return YES;
-}
-
 #pragma mark - UIViewController
 
 - (void)viewDidLoad {

diff --git a/ios/chrome/browser/ui/reading_list/reading_list_view_controller_container.mm b/ios/chrome/browser/ui/reading_list/reading_list_view_controller_container.mm
index d3747b2..5da64cc 100644
--- a/ios/chrome/browser/ui/reading_list/reading_list_view_controller_container.mm
+++ b/ios/chrome/browser/ui/reading_list/reading_list_view_controller_container.mm

@@ -88,6 +88,13 @@
   return NO;
 }
 
+#pragma mark UIAccessibilityAction
+
+- (BOOL)accessibilityPerformEscape {
+  [self dismiss];
+  return YES;
+}
+
 #pragma mark - ReadingListViewControllerAudience
 
 - (void)setCollectionHasItems:(BOOL)hasItems {

diff --git a/ios/chrome/browser/ui/settings/translate_collection_view_controller.mm b/ios/chrome/browser/ui/settings/translate_collection_view_controller.mm
index 6dd5036..25973246 100644
--- a/ios/chrome/browser/ui/settings/translate_collection_view_controller.mm
+++ b/ios/chrome/browser/ui/settings/translate_collection_view_controller.mm

@@ -8,6 +8,7 @@
 #include <memory>
 
 #include "base/mac/foundation_util.h"
+#include "base/mac/scoped_nsobject.h"
 #include "components/google/core/browser/google_util.h"
 #include "components/prefs/pref_member.h"
 #include "components/prefs/pref_service.h"

diff --git a/ios/clean/DEPS b/ios/clean/DEPS
index 81d0c5a8..7973743 100644
--- a/ios/clean/DEPS
+++ b/ios/clean/DEPS

@@ -2,5 +2,6 @@
   "+net",
   "+ui/base",
   "+ios/chrome",
+  "+ios/shared",
   "+ios/web",
 ]

diff --git a/ios/clean/chrome/browser/BUILD.gn b/ios/clean/chrome/browser/BUILD.gn
index eaab38f..579d6d0 100644
--- a/ios/clean/chrome/browser/BUILD.gn
+++ b/ios/clean/chrome/browser/BUILD.gn

@@ -18,6 +18,7 @@
     "//ios/chrome/browser",
     "//ios/chrome/browser/browser_state",
     "//ios/chrome/browser/tabs:tabs_internal",
+    "//ios/shared/chrome/browser/coordinator_context",
   ]
 }
 

diff --git a/ios/clean/chrome/browser/browser_coordinator.h b/ios/clean/chrome/browser/browser_coordinator.h
index 6efa0f2..06d7035 100644
--- a/ios/clean/chrome/browser/browser_coordinator.h
+++ b/ios/clean/chrome/browser/browser_coordinator.h

@@ -11,6 +11,7 @@
 
 #import <UIKit/UIKit.h>
 
+@class CoordinatorContext;
 namespace ios {
 class ChromeBrowserState;
 }
@@ -22,6 +23,9 @@
 // call, or reset.
 @interface BrowserCoordinator : NSObject
 
+// The context object for this coordinator.
+@property(nonatomic, strong, readonly) CoordinatorContext* context;
+
 // The browser state used by this coordinator and passed into any child
 // coordinators added to it. This is a weak pointer, and setting this property
 // doesn't transfer ownership of the browser state.

diff --git a/ios/clean/chrome/browser/browser_coordinator.mm b/ios/clean/chrome/browser/browser_coordinator.mm
index 42cd8a1..9305297 100644
--- a/ios/clean/chrome/browser/browser_coordinator.mm
+++ b/ios/clean/chrome/browser/browser_coordinator.mm

@@ -9,6 +9,7 @@
 #import "base/logging.h"
 #import "ios/clean/chrome/browser/browser_coordinator+internal.h"
 #import "ios/clean/chrome/browser/browser_coordinator.h"
+#import "ios/shared/chrome/browser/coordinator_context/coordinator_context.h"
 
 #if !defined(__has_feature) || !__has_feature(objc_arc)
 #error "This file requires ARC support."
@@ -25,6 +26,7 @@
 
 @implementation BrowserCoordinator
 
+@synthesize context = _context;
 @synthesize browserState = _browserState;
 @synthesize rootViewController = _rootViewController;
 @synthesize childCoordinators = _childCoordinators;
@@ -33,6 +35,7 @@
 
 - (instancetype)init {
   if (self = [super init]) {
+    _context = [[CoordinatorContext alloc] init];
     _childCoordinators = [NSMutableSet set];
   }
   return self;

diff --git a/ios/clean/chrome/browser/ui/settings/BUILD.gn b/ios/clean/chrome/browser/ui/settings/BUILD.gn
index c837f6bf..c10b381 100644
--- a/ios/clean/chrome/browser/ui/settings/BUILD.gn
+++ b/ios/clean/chrome/browser/ui/settings/BUILD.gn

@@ -15,5 +15,6 @@
     "//ios/clean/chrome/browser",
     "//ios/clean/chrome/browser/ui/actions",
     "//ios/clean/chrome/browser/ui/commands",
+    "//ios/shared/chrome/browser/coordinator_context",
   ]
 }

diff --git a/ios/clean/chrome/browser/ui/settings/settings_coordinator.mm b/ios/clean/chrome/browser/ui/settings/settings_coordinator.mm
index c0ef8d7..127778a4 100644
--- a/ios/clean/chrome/browser/ui/settings/settings_coordinator.mm
+++ b/ios/clean/chrome/browser/ui/settings/settings_coordinator.mm

@@ -11,6 +11,7 @@
 #import "ios/chrome/browser/ui/settings/settings_navigation_controller.h"
 #import "ios/clean/chrome/browser/browser_coordinator+internal.h"
 #import "ios/clean/chrome/browser/ui/commands/settings_commands.h"
+#import "ios/shared/chrome/browser/coordinator_context/coordinator_context.h"
 
 #if !defined(__has_feature) || !__has_feature(objc_arc)
 #error "This file requires ARC support."
@@ -32,12 +33,13 @@
                                 currentBrowserState:self.browserState
                                            delegate:self];
   [self.rootViewController presentViewController:self.viewController
-                                        animated:YES
+                                        animated:self.context.animated
                                       completion:nil];
 }
 
 - (void)stop {
-  [self.viewController dismissViewControllerAnimated:YES completion:nil];
+  [self.viewController dismissViewControllerAnimated:self.context.animated
+                                          completion:nil];
 }
 
 #pragma mark - SettingsNavigationControllerDelegate

diff --git a/ios/clean/chrome/browser/ui/tab/BUILD.gn b/ios/clean/chrome/browser/ui/tab/BUILD.gn
index d0146d1..b1177b0 100644
--- a/ios/clean/chrome/browser/ui/tab/BUILD.gn
+++ b/ios/clean/chrome/browser/ui/tab/BUILD.gn

@@ -20,6 +20,7 @@
     "//ios/clean/chrome/browser/ui/presenters",
     "//ios/clean/chrome/browser/ui/toolbar",
     "//ios/clean/chrome/browser/ui/web_contents",
+    "//ios/shared/chrome/browser/coordinator_context",
     "//ios/web",
   ]
 }

diff --git a/ios/clean/chrome/browser/ui/tab/tab_coordinator.mm b/ios/clean/chrome/browser/ui/tab/tab_coordinator.mm
index 2383dd7..321600d2 100644
--- a/ios/clean/chrome/browser/ui/tab/tab_coordinator.mm
+++ b/ios/clean/chrome/browser/ui/tab/tab_coordinator.mm

@@ -17,6 +17,7 @@
 #import "ios/clean/chrome/browser/ui/tab/tab_container_view_controller.h"
 #import "ios/clean/chrome/browser/ui/toolbar/toolbar_coordinator.h"
 #import "ios/clean/chrome/browser/ui/web_contents/web_coordinator.h"
+#import "ios/shared/chrome/browser/coordinator_context/coordinator_context.h"
 #import "ios/web/public/web_state/web_state_observer_bridge.h"
 
 #if !defined(__has_feature) || !__has_feature(objc_arc)
@@ -69,12 +70,13 @@
   self.viewController.contentViewController = webCoordinator.viewController;
 
   [self.rootViewController presentViewController:self.viewController
-                                        animated:YES
+                                        animated:self.context.animated
                                       completion:nil];
 }
 
 - (void)stop {
-  [self.viewController dismissViewControllerAnimated:YES completion:nil];
+  [self.viewController dismissViewControllerAnimated:self.context.animated
+                                          completion:nil];
   _webStateObserver.reset();
 }
 

diff --git a/ios/clean/chrome/browser/ui/tab_grid/BUILD.gn b/ios/clean/chrome/browser/ui/tab_grid/BUILD.gn
index 95850733..01b3f2b7 100644
--- a/ios/clean/chrome/browser/ui/tab_grid/BUILD.gn
+++ b/ios/clean/chrome/browser/ui/tab_grid/BUILD.gn

@@ -18,6 +18,7 @@
     "//ios/clean/chrome/browser/ui/commands",
     "//ios/clean/chrome/browser/ui/settings",
     "//ios/clean/chrome/browser/ui/tab_strip",
+    "//ios/shared/chrome/browser/coordinator_context",
     "//ios/web",
     "//net",
     "//ui/base",

diff --git a/ios/clean/chrome/browser/ui/tab_grid/tab_grid_coordinator.mm b/ios/clean/chrome/browser/ui/tab_grid/tab_grid_coordinator.mm
index 2b477e3..c99fbb9 100644
--- a/ios/clean/chrome/browser/ui/tab_grid/tab_grid_coordinator.mm
+++ b/ios/clean/chrome/browser/ui/tab_grid/tab_grid_coordinator.mm

@@ -17,8 +17,9 @@
 #import "ios/clean/chrome/browser/ui/commands/tab_commands.h"
 #import "ios/clean/chrome/browser/ui/commands/tab_grid_commands.h"
 #import "ios/clean/chrome/browser/ui/settings/settings_coordinator.h"
-#import "ios/clean/chrome/browser/ui/tab_strip/tab_strip_container_coordinator.h"
 #import "ios/clean/chrome/browser/ui/tab_grid/tab_grid_view_controller.h"
+#import "ios/clean/chrome/browser/ui/tab_strip/tab_strip_container_coordinator.h"
+#import "ios/shared/chrome/browser/coordinator_context/coordinator_context.h"
 #import "ios/web/public/navigation_manager.h"
 #include "ios/web/public/web_state/web_state.h"
 #import "net/base/mac/url_conversions.h"
@@ -56,7 +57,7 @@
   // been set. This may be true in a unit test, or if this coordinator is being
   // used as a root coordinator.
   [self.rootViewController presentViewController:self.viewController
-                                        animated:YES
+                                        animated:self.context.animated
                                       completion:nil];
 }
 

diff --git a/ios/clean/chrome/browser/ui/tab_strip/tab_strip_container_view_controller.mm b/ios/clean/chrome/browser/ui/tab_strip/tab_strip_container_view_controller.mm
index 4afbb09..3d94171 100644
--- a/ios/clean/chrome/browser/ui/tab_strip/tab_strip_container_view_controller.mm
+++ b/ios/clean/chrome/browser/ui/tab_strip/tab_strip_container_view_controller.mm

@@ -8,8 +8,8 @@
 
 #import "ios/clean/chrome/browser/ui/tab_strip/tab_strip_container_view_controller.h"
 
-#import "ios/clean/chrome/browser/ui/ui_types.h"
 #import "ios/clean/chrome/browser/ui/actions/tab_strip_actions.h"
+#import "ios/clean/chrome/browser/ui/ui_types.h"
 
 #if !defined(__has_feature) || !__has_feature(objc_arc)
 #error "This file requires ARC support."

diff --git a/ios/clean/chrome/browser/ui/toolbar/BUILD.gn b/ios/clean/chrome/browser/ui/toolbar/BUILD.gn
index 44936952..dd46a48b 100644
--- a/ios/clean/chrome/browser/ui/toolbar/BUILD.gn
+++ b/ios/clean/chrome/browser/ui/toolbar/BUILD.gn

@@ -21,6 +21,7 @@
     "//ios/clean/chrome/browser/ui/animators",
     "//ios/clean/chrome/browser/ui/commands",
     "//ios/clean/chrome/browser/ui/tools",
+    "//ios/shared/chrome/browser/coordinator_context",
     "//ios/web",
   ]
 }

diff --git a/ios/clean/chrome/browser/ui/toolbar/toolbar_coordinator.mm b/ios/clean/chrome/browser/ui/toolbar/toolbar_coordinator.mm
index aba4969d..ed965fe 100644
--- a/ios/clean/chrome/browser/ui/toolbar/toolbar_coordinator.mm
+++ b/ios/clean/chrome/browser/ui/toolbar/toolbar_coordinator.mm

@@ -13,6 +13,7 @@
 #import "ios/clean/chrome/browser/ui/commands/toolbar_commands.h"
 #import "ios/clean/chrome/browser/ui/toolbar/toolbar_view_controller.h"
 #import "ios/clean/chrome/browser/ui/tools/tools_coordinator.h"
+#import "ios/shared/chrome/browser/coordinator_context/coordinator_context.h"
 #include "ios/web/public/web_state/web_state.h"
 
 #if !defined(__has_feature) || !__has_feature(objc_arc)
@@ -33,7 +34,7 @@
   self.viewController.toolbarCommandHandler = self;
 
   [self.rootViewController presentViewController:self.viewController
-                                        animated:YES
+                                        animated:self.context.animated
                                       completion:nil];
 }
 

diff --git a/ios/clean/chrome/browser/ui/tools/BUILD.gn b/ios/clean/chrome/browser/ui/tools/BUILD.gn
index c764d0a..cb3e9b0b 100644
--- a/ios/clean/chrome/browser/ui/tools/BUILD.gn
+++ b/ios/clean/chrome/browser/ui/tools/BUILD.gn

@@ -17,6 +17,7 @@
     "//ios/clean/chrome/browser/ui/actions",
     "//ios/clean/chrome/browser/ui/animators",
     "//ios/clean/chrome/browser/ui/presenters",
+    "//ios/shared/chrome/browser/coordinator_context",
   ]
 }
 

diff --git a/ios/clean/chrome/browser/ui/tools/tools_coordinator.mm b/ios/clean/chrome/browser/ui/tools/tools_coordinator.mm
index 3d01ac2..7bc1c72 100644
--- a/ios/clean/chrome/browser/ui/tools/tools_coordinator.mm
+++ b/ios/clean/chrome/browser/ui/tools/tools_coordinator.mm

@@ -11,6 +11,7 @@
 #import "ios/clean/chrome/browser/ui/animators/zoom_transition_animator.h"
 #import "ios/clean/chrome/browser/ui/presenters/menu_presentation_controller.h"
 #import "ios/clean/chrome/browser/ui/tools/menu_view_controller.h"
+#import "ios/shared/chrome/browser/coordinator_context/coordinator_context.h"
 
 #if !defined(__has_feature) || !__has_feature(objc_arc)
 #error "This file requires ARC support."
@@ -32,12 +33,13 @@
   self.menuViewController.transitioningDelegate = self;
 
   [self.rootViewController presentViewController:self.menuViewController
-                                        animated:YES
+                                        animated:self.context.animated
                                       completion:nil];
 }
 
 - (void)stop {
-  [self.menuViewController dismissViewControllerAnimated:YES completion:nil];
+  [self.menuViewController dismissViewControllerAnimated:self.context.animated
+                                              completion:nil];
 }
 
 #pragma mark - UIViewControllerTransitioningDelegate

diff --git a/ios/clean/chrome/browser/ui/web_contents/BUILD.gn b/ios/clean/chrome/browser/ui/web_contents/BUILD.gn
index 4650fac..df8e8c68 100644
--- a/ios/clean/chrome/browser/ui/web_contents/BUILD.gn
+++ b/ios/clean/chrome/browser/ui/web_contents/BUILD.gn

@@ -15,6 +15,7 @@
   deps = [
     "//ios/clean/chrome/browser",
     "//ios/clean/chrome/browser/web",
+    "//ios/shared/chrome/browser/coordinator_context",
     "//ios/web",
     "//ui/base",
     "//url",

diff --git a/ios/clean/chrome/browser/ui/web_contents/web_coordinator.mm b/ios/clean/chrome/browser/ui/web_contents/web_coordinator.mm
index ab02726..70327bcc 100644
--- a/ios/clean/chrome/browser/ui/web_contents/web_coordinator.mm
+++ b/ios/clean/chrome/browser/ui/web_contents/web_coordinator.mm

@@ -10,6 +10,7 @@
 
 #import "ios/clean/chrome/browser/browser_coordinator+internal.h"
 #import "ios/clean/chrome/browser/ui/web_contents/web_contents_view_controller.h"
+#import "ios/shared/chrome/browser/coordinator_context/coordinator_context.h"
 
 #if !defined(__has_feature) || !__has_feature(objc_arc)
 #error "This file requires ARC support."
@@ -34,7 +35,7 @@
   // when this coordinator's view controller will be contained instead of
   // presented.
   [self.rootViewController presentViewController:self.viewController
-                                        animated:YES
+                                        animated:self.context.animated
                                       completion:nil];
 }
 

diff --git a/ios/shared/DEPS b/ios/shared/DEPS
new file mode 100644
index 0000000..f47a8e23
--- /dev/null
+++ b/ios/shared/DEPS

@@ -0,0 +1,5 @@
+include_rules = [
+  # Shared code between ios/chrome and ios/clean/chrome must not depend on them.
+  "-ios/clean/chrome",
+  "-ios/chrome",
+]

diff --git a/ios/shared/OWNERS b/ios/shared/OWNERS
new file mode 100644
index 0000000..b8d3d41f
--- /dev/null
+++ b/ios/shared/OWNERS

@@ -0,0 +1,3 @@
+lpromero@chromium.org
+marq@chromium.org
+sdefresne@chromium.org

diff --git a/ios/shared/README.md b/ios/shared/README.md
new file mode 100644
index 0000000..94ad31b
--- /dev/null
+++ b/ios/shared/README.md

@@ -0,0 +1,5 @@
+# Shared directory between ios/chrome and ios/clean/chrome
+
+This directory is here to hold the shared code between `ios/chrome` and
+`ios/clean/chrome`.
+Code in this directory should not depend on either.

diff --git a/ios/shared/chrome/browser/coordinator_context/BUILD.gn b/ios/shared/chrome/browser/coordinator_context/BUILD.gn
new file mode 100644
index 0000000..4f3f5c2
--- /dev/null
+++ b/ios/shared/chrome/browser/coordinator_context/BUILD.gn

@@ -0,0 +1,24 @@
+# Copyright 2017 The Chromium Authors. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+source_set("coordinator_context") {
+  sources = [
+    "coordinator_context.h",
+    "coordinator_context.mm",
+  ]
+  configs += [ "//build/config/compiler:enable_arc" ]
+  libs = [ "UIKit.framework" ]
+}
+
+source_set("unit_tests") {
+  testonly = true
+  sources = [
+    "coordinator_context_unittest.mm",
+  ]
+  deps = [
+    ":coordinator_context",
+    "//testing/gtest",
+  ]
+  configs += [ "//build/config/compiler:enable_arc" ]
+}

diff --git a/ios/shared/chrome/browser/coordinator_context/coordinator_context.h b/ios/shared/chrome/browser/coordinator_context/coordinator_context.h
new file mode 100644
index 0000000..f52a62c
--- /dev/null
+++ b/ios/shared/chrome/browser/coordinator_context/coordinator_context.h

@@ -0,0 +1,17 @@
+// Copyright 2017 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef IOS_SHARED_CHROME_BROWSER_COORDINATOR_CONTEXT_COORDINATOR_CONTEXT_H_
+#define IOS_SHARED_CHROME_BROWSER_COORDINATOR_CONTEXT_COORDINATOR_CONTEXT_H_
+
+#import <UIKit/UIKit.h>
+
+@interface CoordinatorContext : NSObject
+
+// Default is YES.
+@property(nonatomic, assign, getter=isAnimated) BOOL animated;
+
+@end
+
+#endif  // IOS_SHARED_CHROME_BROWSER_COORDINATOR_CONTEXT_COORDINATOR_CONTEXT_H_

diff --git a/ios/shared/chrome/browser/coordinator_context/coordinator_context.mm b/ios/shared/chrome/browser/coordinator_context/coordinator_context.mm
new file mode 100644
index 0000000..f53d002
--- /dev/null
+++ b/ios/shared/chrome/browser/coordinator_context/coordinator_context.mm

@@ -0,0 +1,23 @@
+// Copyright 2017 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#import "ios/shared/chrome/browser/coordinator_context/coordinator_context.h"
+
+#if !defined(__has_feature) || !__has_feature(objc_arc)
+#error "This file requires ARC support."
+#endif
+
+@implementation CoordinatorContext
+
+@synthesize animated = _animated;
+
+- (instancetype)init {
+  self = [super init];
+  if (self) {
+    _animated = YES;
+  }
+  return self;
+}
+
+@end

diff --git a/ios/shared/chrome/browser/coordinator_context/coordinator_context_unittest.mm b/ios/shared/chrome/browser/coordinator_context/coordinator_context_unittest.mm
new file mode 100644
index 0000000..30e377d
--- /dev/null
+++ b/ios/shared/chrome/browser/coordinator_context/coordinator_context_unittest.mm

@@ -0,0 +1,20 @@
+// Copyright 2017 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#import "ios/shared/chrome/browser/coordinator_context/coordinator_context.h"
+
+#include "testing/gtest/include/gtest/gtest.h"
+
+#if !defined(__has_feature) || !__has_feature(objc_arc)
+#error "This file requires ARC support."
+#endif
+
+namespace {
+
+TEST(CoordinatorContextTest, Initialization) {
+  CoordinatorContext* context = [[CoordinatorContext alloc] init];
+  EXPECT_TRUE(context.animated);
+}
+
+}  // namespace

diff --git a/media/audio/linux/audio_manager_linux.cc b/media/audio/linux/audio_manager_linux.cc
index 5d9676e..374d2ab8 100644
--- a/media/audio/linux/audio_manager_linux.cc
+++ b/media/audio/linux/audio_manager_linux.cc

@@ -3,7 +3,7 @@
 // found in the LICENSE file.
 
 #include "base/command_line.h"
-#include "base/metrics/histogram.h"
+#include "base/metrics/histogram_macros.h"
 #include "media/base/media_switches.h"
 
 #if defined(USE_ALSA)

diff --git a/media/filters/gpu_video_decoder.cc b/media/filters/gpu_video_decoder.cc
index 124f8c0b..d4c064f 100644
--- a/media/filters/gpu_video_decoder.cc
+++ b/media/filters/gpu_video_decoder.cc

@@ -253,7 +253,7 @@
       factories_->GetVideoDecodeAcceleratorCapabilities();
   if (!IsProfileSupported(capabilities, config.profile(), config.coded_size(),
                           config.is_encrypted())) {
-    DVLOG(1) << "Unsupported profile " << config.profile()
+    DVLOG(1) << "Unsupported profile " << GetProfileName(config.profile())
              << ", unsupported coded size " << config.coded_size().ToString()
              << ", or accelerator should only be used for encrypted content. "
              << " is_encrypted: " << (config.is_encrypted() ? "yes." : "no.");

diff --git a/media/gpu/android_video_decode_accelerator.cc b/media/gpu/android_video_decode_accelerator.cc
index c907c601..c26289c 100644
--- a/media/gpu/android_video_decode_accelerator.cc
+++ b/media/gpu/android_video_decode_accelerator.cc

@@ -289,7 +289,7 @@
       codec_config_->codec != kCodecHEVC &&
 #endif
       codec_config_->codec != kCodecH264) {
-    DLOG(ERROR) << "Unsupported profile: " << config.profile;
+    DLOG(ERROR) << "Unsupported profile: " << GetProfileName(config.profile);
     return false;
   }
 

diff --git a/media/gpu/android_video_encode_accelerator.cc b/media/gpu/android_video_encode_accelerator.cc
index 2e8559dd..cfad7fa 100644
--- a/media/gpu/android_video_encode_accelerator.cc
+++ b/media/gpu/android_video_encode_accelerator.cc

@@ -156,7 +156,8 @@
 
   if (!(MediaCodecUtil::SupportsSetParameters() &&
         format == PIXEL_FORMAT_I420)) {
-    DLOG(ERROR) << "Unexpected combo: " << format << ", " << output_profile;
+    DLOG(ERROR) << "Unexpected combo: " << format << ", "
+                << GetProfileName(output_profile);
     return false;
   }
 

diff --git a/media/gpu/vaapi_video_decode_accelerator.cc b/media/gpu/vaapi_video_decode_accelerator.cc
index a119f0f..8c73ccc 100644
--- a/media/gpu/vaapi_video_decode_accelerator.cc
+++ b/media/gpu/vaapi_video_decode_accelerator.cc

@@ -359,7 +359,7 @@
 
   base::AutoLock auto_lock(lock_);
   DCHECK_EQ(state_, kUninitialized);
-  DVLOG(2) << "Initializing VAVDA, profile: " << profile;
+  DVLOG(2) << "Initializing VAVDA, profile: " << GetProfileName(profile);
 
 #if defined(USE_X11)
   if (gl::GetGLImplementation() != gl::kGLImplementationDesktopGL) {
@@ -379,7 +379,8 @@
       VaapiWrapper::kDecode, profile, base::Bind(&ReportToUMA, VAAPI_ERROR));
 
   if (!vaapi_wrapper_.get()) {
-    DVLOG(1) << "Failed initializing VAAPI for profile " << profile;
+    DVLOG(1) << "Failed initializing VAAPI for profile "
+             << GetProfileName(profile);
     return false;
   }
 
@@ -394,7 +395,7 @@
     vp9_accelerator_.reset(new VaapiVP9Accelerator(this, vaapi_wrapper_.get()));
     decoder_.reset(new VP9Decoder(vp9_accelerator_.get()));
   } else {
-    DLOG(ERROR) << "Unsupported profile " << profile;
+    DLOG(ERROR) << "Unsupported profile " << GetProfileName(profile);
     return false;
   }
 

diff --git a/media/gpu/vaapi_video_encode_accelerator.cc b/media/gpu/vaapi_video_encode_accelerator.cc
index 6505bb57..bf77ad7 100644
--- a/media/gpu/vaapi_video_encode_accelerator.cc
+++ b/media/gpu/vaapi_video_encode_accelerator.cc

@@ -167,7 +167,7 @@
   DVLOGF(1) << "Initializing VAVEA, input_format: "
             << VideoPixelFormatToString(format)
             << ", input_visible_size: " << input_visible_size.ToString()
-            << ", output_profile: " << output_profile
+            << ", output_profile: " << GetProfileName(output_profile)
             << ", initial_bitrate: " << initial_bitrate;
 
   client_ptr_factory_.reset(new base::WeakPtrFactory<Client>(client));
@@ -179,7 +179,8 @@
                            return profile.profile == output_profile;
                          });
   if (profile == profiles.end()) {
-    DVLOGF(1) << "Unsupported output profile " << output_profile;
+    DVLOGF(1) << "Unsupported output profile "
+              << GetProfileName(output_profile);
     return false;
   }
   if (input_visible_size.width() > profile->max_resolution.width() ||
@@ -212,7 +213,8 @@
       VaapiWrapper::CreateForVideoCodec(VaapiWrapper::kEncode, output_profile,
                                         base::Bind(&ReportToUMA, VAAPI_ERROR));
   if (!vaapi_wrapper_.get()) {
-    DVLOGF(1) << "Failed initializing VAAPI for profile " << output_profile;
+    DVLOGF(1) << "Failed initializing VAAPI for profile "
+              << GetProfileName(output_profile);
     return false;
   }
 

diff --git a/media/gpu/video_decode_accelerator_unittest.cc b/media/gpu/video_decode_accelerator_unittest.cc
index 6723474..dea106b 100644
--- a/media/gpu/video_decode_accelerator_unittest.cc
+++ b/media/gpu/video_decode_accelerator_unittest.cc

@@ -1012,7 +1012,7 @@
     return (size > 0 && !(data[0] & 0x01));
   }
   // Shouldn't happen at this point.
-  LOG(FATAL) << "Invalid profile: " << profile;
+  LOG(FATAL) << "Invalid profile: " << GetProfileName(profile);
   return false;
 }
 

diff --git a/media/gpu/video_encode_accelerator_unittest.cc b/media/gpu/video_encode_accelerator_unittest.cc
index ded9b86..11f019b9 100644
--- a/media/gpu/video_encode_accelerator_unittest.cc
+++ b/media/gpu/video_encode_accelerator_unittest.cc

@@ -700,7 +700,7 @@
   } else if (IsVP8(profile)) {
     validator.reset(new VP8Validator(frame_cb));
   } else {
-    LOG(FATAL) << "Unsupported profile: " << profile;
+    LOG(FATAL) << "Unsupported profile: " << GetProfileName(profile);
   }
 
   return validator;
@@ -773,7 +773,7 @@
                       COLOR_SPACE_UNSPECIFIED, coded_size, visible_size,
                       natural_size, EmptyExtraData(), Unencrypted());
   else
-    LOG_ASSERT(0) << "Invalid profile " << profile_;
+    LOG_ASSERT(0) << "Invalid profile " << GetProfileName(profile_);
 
   decoder_->Initialize(
       config, false, nullptr,

diff --git a/media/gpu/vt_video_encode_accelerator_mac.cc b/media/gpu/vt_video_encode_accelerator_mac.cc
index cc5ed0d0..f5aff7e 100644
--- a/media/gpu/vt_video_encode_accelerator_mac.cc
+++ b/media/gpu/vt_video_encode_accelerator_mac.cc

@@ -123,7 +123,7 @@
                                           Client* client) {
   DVLOG(3) << __func__ << ": input_format=" << VideoPixelFormatToString(format)
            << ", input_visible_size=" << input_visible_size.ToString()
-           << ", output_profile=" << output_profile
+           << ", output_profile=" << GetProfileName(output_profile)
            << ", initial_bitrate=" << initial_bitrate;
   DCHECK(thread_checker_.CalledOnValidThread());
   DCHECK(client);
@@ -134,7 +134,8 @@
     return false;
   }
   if (H264PROFILE_BASELINE != output_profile) {
-    DLOG(ERROR) << "Output profile not supported= " << output_profile;
+    DLOG(ERROR) << "Output profile not supported= "
+                << GetProfileName(output_profile);
     return false;
   }
 

diff --git a/skia/BUILD.gn b/skia/BUILD.gn
index 2b154a7..8e14ac1 100644
--- a/skia/BUILD.gn
+++ b/skia/BUILD.gn

@@ -93,6 +93,7 @@
     "//third_party/skia/include/private",
     "//third_party/skia/include/client/android",
     "//third_party/skia/src/core",
+    "//third_party/skia/src/effects/gradients",
     "//third_party/skia/src/image",
     "//third_party/skia/src/opts",
     "//third_party/skia/src/pdf",

diff --git a/testing/buildbot/chromium.chromiumos.json b/testing/buildbot/chromium.chromiumos.json
index 73d3a37..7946643 100644
--- a/testing/buildbot/chromium.chromiumos.json
+++ b/testing/buildbot/chromium.chromiumos.json

@@ -179,10 +179,13 @@
         "test": "gl_unittests"
       },
       {
+        "args": [
+          "--ozone-platform=x11"
+        ],
         "swarming": {
           "can_use_on_swarming_builders": true
         },
-        "test": "gl_unittests_ozonex"
+        "test": "gl_unittests_ozone"
       },
       {
         "swarming": {

diff --git a/testing/buildbot/gn_isolate_map.pyl b/testing/buildbot/gn_isolate_map.pyl
index 7c4e712..b85c1e7 100644
--- a/testing/buildbot/gn_isolate_map.pyl
+++ b/testing/buildbot/gn_isolate_map.pyl

@@ -26,8 +26,7 @@
 #  "windowed_test_launcher"
 #  : the test is a gtest-based test that uses the "brave-new-test-launcher"
 #    from //base/test:test_support and needs to run under Xvfb if run on
-#    an X11-based platform (use_x11=true or use_ozone=true &&
-#    --ozone_platform=x11).
+#    some platforms (eg. Linux Desktop, X11 CrOS and Ozone CrOS).
 #  "console_test_launcher"
 #  : the test is a gtest-based test that uses the "brave-new-test-launcher"
 #    from //base/test:test_support but does not need Xvfb.
@@ -447,12 +446,11 @@
     "type": "raw",
     "args": [],
   },
-  "gl_unittests_ozonex": {
-    "label": "//ui/gl:gl_unittests_ozonex",
+  "gl_unittests_ozone": {
+    "label": "//ui/gl:gl_unittests_ozone",
     "label_type": "group",
     "type": "windowed_test_launcher",
     "executable": "gl_unittests",
-    "args": ["--ozone-platform=x11"],
   },
   "gn_unittests": {
     "label": "//tools/gn:gn_unittests",

diff --git a/third_party/WebKit/LayoutTests/TestExpectations b/third_party/WebKit/LayoutTests/TestExpectations
index ec2b2a3..90a89f6 100644
--- a/third_party/WebKit/LayoutTests/TestExpectations
+++ b/third_party/WebKit/LayoutTests/TestExpectations

@@ -1629,6 +1629,7 @@
 crbug.com/613659 external/wpt/quirks-mode/percentage-height-calculation.html [ Failure ]
 crbug.com/613661 external/wpt/quirks-mode/table-cell-nowrap-minimum-width-calculation.html [ Failure ]
 crbug.com/613663 external/wpt/quirks-mode/table-cell-width-calculation.html [ Failure ]
+crbug.com/613663 external/wpt/quirks-mode/unitless-length.html [ Failure Timeout ]
 
 # Note: this test was previously marked as slow on Debug builds. Skipping until crash is fixed
 crbug.com/619978 fast/css/giant-stylesheet-crash.html [ Skip ]

diff --git a/third_party/WebKit/LayoutTests/svg/text/tspan-outline-multiple-inline-box-expected.txt b/third_party/WebKit/LayoutTests/svg/text/tspan-outline-multiple-inline-box-expected.txt
index 42dc792c..c0ee13e 100644
--- a/third_party/WebKit/LayoutTests/svg/text/tspan-outline-multiple-inline-box-expected.txt
+++ b/third_party/WebKit/LayoutTests/svg/text/tspan-outline-multiple-inline-box-expected.txt

@@ -1 +1 @@
-Passes if no crash with ENABLE(ASSERT). לגabc
+Passes if no crash with DCHECK_IS_ON(). לגabc

diff --git a/third_party/WebKit/LayoutTests/svg/text/tspan-outline-multiple-inline-box.svg b/third_party/WebKit/LayoutTests/svg/text/tspan-outline-multiple-inline-box.svg
index d23a7df..c7b9f74 100644
--- a/third_party/WebKit/LayoutTests/svg/text/tspan-outline-multiple-inline-box.svg
+++ b/third_party/WebKit/LayoutTests/svg/text/tspan-outline-multiple-inline-box.svg

@@ -4,7 +4,7 @@
       testRunner.dumpAsText();
   </script>
   <text x="100" y="100">
-    Passes if no crash with ENABLE(ASSERT).
+    Passes if no crash with DCHECK_IS_ON().
     &#1500;<tspan style="outline: 1px solid black">&#1490;a</tspan>bc
   </text>
 </svg>

diff --git a/third_party/WebKit/Source/bindings/core/v8/DOMWrapperWorld.cpp b/third_party/WebKit/Source/bindings/core/v8/DOMWrapperWorld.cpp
index d3ece36..eac486e7 100644
--- a/third_party/WebKit/Source/bindings/core/v8/DOMWrapperWorld.cpp
+++ b/third_party/WebKit/Source/bindings/core/v8/DOMWrapperWorld.cpp

@@ -193,7 +193,7 @@
   m_domDataStore.reset();
 }
 
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
 static bool isIsolatedWorldId(int worldId) {
   return MainWorldId < worldId && worldId < IsolatedWorldIdLimit;
 }

diff --git a/third_party/WebKit/Source/bindings/core/v8/ExceptionState.h b/third_party/WebKit/Source/bindings/core/v8/ExceptionState.h
index c34c579..fd45146 100644
--- a/third_party/WebKit/Source/bindings/core/v8/ExceptionState.h
+++ b/third_party/WebKit/Source/bindings/core/v8/ExceptionState.h

@@ -83,7 +83,7 @@
                  ContextType contextType,
                  const char* interfaceName)
       : ExceptionState(isolate, contextType, interfaceName, nullptr) {
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
     switch (m_context) {
       case ConstructionContext:
       case EnumerationContext:
@@ -94,7 +94,7 @@
       default:
         NOTREACHED();
     }
-#endif  // ENABLE(ASSERT)
+#endif  // DCHECK_IS_ON()
   }
 
   ~ExceptionState() {
@@ -176,7 +176,7 @@
 // This can be used as a default value of an ExceptionState parameter like this:
 //
 //     Node* removeChild(Node*, ExceptionState& = ASSERT_NO_EXCEPTION);
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
 #define ASSERT_NO_EXCEPTION \
   (::blink::NonThrowableExceptionState(__FILE__, __LINE__).returnThis())
 #else

diff --git a/third_party/WebKit/Source/bindings/core/v8/ExceptionStatePlaceholder.cpp b/third_party/WebKit/Source/bindings/core/v8/ExceptionStatePlaceholder.cpp
index 3c2e4beb..709ebf73 100644
--- a/third_party/WebKit/Source/bindings/core/v8/ExceptionStatePlaceholder.cpp
+++ b/third_party/WebKit/Source/bindings/core/v8/ExceptionStatePlaceholder.cpp

@@ -32,7 +32,7 @@
 
 namespace blink {
 
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
 
 NoExceptionStateAssertionChecker::NoExceptionStateAssertionChecker(
     const char* file,

diff --git a/third_party/WebKit/Source/bindings/core/v8/ScriptFunction.cpp b/third_party/WebKit/Source/bindings/core/v8/ScriptFunction.cpp
index 1c448de6..f9ee245 100644
--- a/third_party/WebKit/Source/bindings/core/v8/ScriptFunction.cpp
+++ b/third_party/WebKit/Source/bindings/core/v8/ScriptFunction.cpp

@@ -9,7 +9,7 @@
 namespace blink {
 
 v8::Local<v8::Function> ScriptFunction::bindToV8Function() {
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
   DCHECK(!m_bindToV8FunctionAlreadyCalled);
   m_bindToV8FunctionAlreadyCalled = true;
 #endif

diff --git a/third_party/WebKit/Source/bindings/core/v8/ScriptFunction.h b/third_party/WebKit/Source/bindings/core/v8/ScriptFunction.h
index 6a7f96e1..3a4b150 100644
--- a/third_party/WebKit/Source/bindings/core/v8/ScriptFunction.h
+++ b/third_party/WebKit/Source/bindings/core/v8/ScriptFunction.h

@@ -59,10 +59,6 @@
  protected:
   explicit ScriptFunction(ScriptState* scriptState)
       : m_scriptState(scriptState)
-#if ENABLE(ASSERT)
-        ,
-        m_bindToV8FunctionAlreadyCalled(false)
-#endif
   {
   }
 
@@ -75,9 +71,9 @@
   static void callCallback(const v8::FunctionCallbackInfo<v8::Value>&);
 
   RefPtr<ScriptState> m_scriptState;
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
   // bindToV8Function must not be called twice.
-  bool m_bindToV8FunctionAlreadyCalled;
+  bool m_bindToV8FunctionAlreadyCalled = false;
 #endif
 };
 

diff --git a/third_party/WebKit/Source/bindings/core/v8/ScriptPromiseResolver.cpp b/third_party/WebKit/Source/bindings/core/v8/ScriptPromiseResolver.cpp
index 37d6ee3..f38e7163 100644
--- a/third_party/WebKit/Source/bindings/core/v8/ScriptPromiseResolver.cpp
+++ b/third_party/WebKit/Source/bindings/core/v8/ScriptPromiseResolver.cpp

@@ -17,10 +17,6 @@
               this,
               &ScriptPromiseResolver::onTimerFired),
       m_resolver(scriptState)
-#if ENABLE(ASSERT)
-      ,
-      m_isPromiseCalled(false)
-#endif
 {
   if (getExecutionContext()->isContextDestroyed()) {
     m_state = Detached;

diff --git a/third_party/WebKit/Source/bindings/core/v8/ScriptPromiseResolver.h b/third_party/WebKit/Source/bindings/core/v8/ScriptPromiseResolver.h
index 3a62b45..0258371a 100644
--- a/third_party/WebKit/Source/bindings/core/v8/ScriptPromiseResolver.h
+++ b/third_party/WebKit/Source/bindings/core/v8/ScriptPromiseResolver.h

@@ -41,7 +41,7 @@
     return resolver;
   }
 
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
   // Eagerly finalized so as to ensure valid access to getExecutionContext()
   // from the destructor's assert.
   EAGERLY_FINALIZE();
@@ -78,7 +78,7 @@
   // Note that an empty ScriptPromise will be returned after resolve or
   // reject is called.
   ScriptPromise promise() {
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
     m_isPromiseCalled = true;
 #endif
     return m_resolver.promise();
@@ -161,9 +161,9 @@
   // alive while in that state.
   SelfKeepAlive<ScriptPromiseResolver> m_keepAlive;
 
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
   // True if promise() is called.
-  bool m_isPromiseCalled;
+  bool m_isPromiseCalled = false;
 #endif
 };
 

diff --git a/third_party/WebKit/Source/bindings/core/v8/ScriptState.cpp b/third_party/WebKit/Source/bindings/core/v8/ScriptState.cpp
index c16c328b..8f84ae2 100644
--- a/third_party/WebKit/Source/bindings/core/v8/ScriptState.cpp
+++ b/third_party/WebKit/Source/bindings/core/v8/ScriptState.cpp

@@ -36,10 +36,6 @@
       m_context(m_isolate, context),
       m_world(world),
       m_perContextData(V8PerContextData::create(context))
-#if ENABLE(ASSERT)
-      ,
-      m_globalObjectDetached(false)
-#endif
 {
   DCHECK(m_world);
   m_context.setWeak(this, &weakCallback);
@@ -54,7 +50,7 @@
 void ScriptState::detachGlobalObject() {
   ASSERT(!m_context.isEmpty());
   context()->DetachGlobal();
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
   m_globalObjectDetached = true;
 #endif
 }

diff --git a/third_party/WebKit/Source/bindings/core/v8/ScriptState.h b/third_party/WebKit/Source/bindings/core/v8/ScriptState.h
index 65b6f73..4d8d0fe 100644
--- a/third_party/WebKit/Source/bindings/core/v8/ScriptState.h
+++ b/third_party/WebKit/Source/bindings/core/v8/ScriptState.h

@@ -155,7 +155,7 @@
   }
   void detachGlobalObject();
   void clearContext() { return m_context.clear(); }
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
   bool isGlobalObjectDetached() const { return m_globalObjectDetached; }
 #endif
 
@@ -184,8 +184,8 @@
   // Otherwise, the v8::Context will leak.
   std::unique_ptr<V8PerContextData> m_perContextData;
 
-#if ENABLE(ASSERT)
-  bool m_globalObjectDetached;
+#if DCHECK_IS_ON()
+  bool m_globalObjectDetached = false;
 #endif
 };
 

diff --git a/third_party/WebKit/Source/bindings/core/v8/ScriptValueSerializer.cpp b/third_party/WebKit/Source/bindings/core/v8/ScriptValueSerializer.cpp
index fd18123..38145b01 100644
--- a/third_party/WebKit/Source/bindings/core/v8/ScriptValueSerializer.cpp
+++ b/third_party/WebKit/Source/bindings/core/v8/ScriptValueSerializer.cpp

@@ -263,7 +263,7 @@
 void SerializedScriptValueWriter::writeArrayBufferView(
     const DOMArrayBufferView& arrayBufferView) {
   append(ArrayBufferViewTag);
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
   ASSERT(static_cast<const uint8_t*>(arrayBufferView.bufferBase()->data()) +
              arrayBufferView.byteOffset() ==
          static_cast<const uint8_t*>(arrayBufferView.baseAddress()));

diff --git a/third_party/WebKit/Source/bindings/core/v8/V8Initializer.cpp b/third_party/WebKit/Source/bindings/core/v8/V8Initializer.cpp
index 0e8ed5a..30e49da 100644
--- a/third_party/WebKit/Source/bindings/core/v8/V8Initializer.cpp
+++ b/third_party/WebKit/Source/bindings/core/v8/V8Initializer.cpp

@@ -365,7 +365,7 @@
 }  // namespace
 
 static void adjustAmountOfExternalAllocatedMemory(int64_t diff) {
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
   DEFINE_THREAD_SAFE_STATIC_LOCAL(int64_t, processTotal, new int64_t(0));
   DEFINE_THREAD_SAFE_STATIC_LOCAL(Mutex, mutex, new Mutex);
   {

diff --git a/third_party/WebKit/Source/bindings/core/v8/V8StringResource.h b/third_party/WebKit/Source/bindings/core/v8/V8StringResource.h
index c01715d4..b6009b8 100644
--- a/third_party/WebKit/Source/bindings/core/v8/V8StringResource.h
+++ b/third_party/WebKit/Source/bindings/core/v8/V8StringResource.h

@@ -44,7 +44,7 @@
  public:
   explicit WebCoreStringResourceBase(const String& string)
       : m_plainString(string) {
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
     m_threadId = WTF::currentThread();
 #endif
     ASSERT(!string.isNull());
@@ -54,7 +54,7 @@
 
   explicit WebCoreStringResourceBase(const AtomicString& string)
       : m_plainString(string.getString()), m_atomicString(string) {
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
     m_threadId = WTF::currentThread();
 #endif
     ASSERT(!string.isNull());
@@ -63,7 +63,7 @@
   }
 
   virtual ~WebCoreStringResourceBase() {
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
     ASSERT(m_threadId == WTF::currentThread());
 #endif
     int64_t reducedExternalMemory = m_plainString.charactersSizeInBytes();
@@ -77,7 +77,7 @@
   const String& webcoreString() { return m_plainString; }
 
   const AtomicString& getAtomicString() {
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
     ASSERT(m_threadId == WTF::currentThread());
 #endif
     if (m_atomicString.isNull()) {
@@ -102,7 +102,7 @@
   AtomicString m_atomicString;
 
  private:
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
   WTF::ThreadIdentifier m_threadId;
 #endif
 };

diff --git a/third_party/WebKit/Source/bindings/core/v8/custom/V8CSSStyleDeclarationCustom.cpp b/third_party/WebKit/Source/bindings/core/v8/custom/V8CSSStyleDeclarationCustom.cpp
index 14e7e7f1..35aa980 100644
--- a/third_party/WebKit/Source/bindings/core/v8/custom/V8CSSStyleDeclarationCustom.cpp
+++ b/third_party/WebKit/Source/bindings/core/v8/custom/V8CSSStyleDeclarationCustom.cpp

@@ -61,7 +61,7 @@
 // The prefix within the property name must be followed by a capital letter.
 static bool hasCSSPropertyNamePrefix(const String& propertyName,
                                      const char* prefix) {
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
   ASSERT(*prefix);
   for (const char* p = prefix; *p; ++p)
     ASSERT(isASCIILower(*p));

diff --git a/third_party/WebKit/Source/bindings/modules/v8/V8BindingForModules.cpp b/third_party/WebKit/Source/bindings/modules/v8/V8BindingForModules.cpp
index 60c44f6..7f2bdfc 100644
--- a/third_party/WebKit/Source/bindings/modules/v8/V8BindingForModules.cpp
+++ b/third_party/WebKit/Source/bindings/modules/v8/V8BindingForModules.cpp

@@ -594,7 +594,7 @@
   return V8IDBKeyRange::toImplWithTypeCheck(isolate, value);
 }
 
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
 // This assertion is used when a value has been retrieved from an object store
 // with implicit keys (i.e. a key path). It verifies that either the value
 // contains an implicit key matching the primary key (so it was correctly

diff --git a/third_party/WebKit/Source/bindings/modules/v8/V8BindingForModules.h b/third_party/WebKit/Source/bindings/modules/v8/V8BindingForModules.h
index 6ae8cbc..522f1983 100644
--- a/third_party/WebKit/Source/bindings/modules/v8/V8BindingForModules.h
+++ b/third_party/WebKit/Source/bindings/modules/v8/V8BindingForModules.h

@@ -32,7 +32,7 @@
                                    SerializedScriptValue*,
                                    const Vector<WebBlobInfo>*);
 
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
 void assertPrimaryKeyValidOrInjectable(ScriptState*, const IDBValue*);
 #endif
 

diff --git a/third_party/WebKit/Source/core/clipboard/DataObject.cpp b/third_party/WebKit/Source/core/clipboard/DataObject.cpp
index ea267e8..fcbbe51 100644
--- a/third_party/WebKit/Source/core/clipboard/DataObject.cpp
+++ b/third_party/WebKit/Source/core/clipboard/DataObject.cpp

@@ -43,7 +43,7 @@
 
 DataObject* DataObject::createFromPasteboard(PasteMode pasteMode) {
   DataObject* dataObject = create();
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
   HashSet<String> typesSeen;
 #endif
   WebClipboard::Buffer buffer = Pasteboard::generalPasteboard()->buffer();
@@ -133,7 +133,7 @@
 
 Vector<String> DataObject::types() const {
   Vector<String> results;
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
   HashSet<String> typesSeen;
 #endif
   bool containsFiles = false;

diff --git a/third_party/WebKit/Source/core/dom/Document.cpp b/third_party/WebKit/Source/core/dom/Document.cpp
index 5f1e6c6..2a35689 100644
--- a/third_party/WebKit/Source/core/dom/Document.cpp
+++ b/third_party/WebKit/Source/core/dom/Document.cpp

@@ -4945,34 +4945,27 @@
 }
 
 KURL Document::completeURL(const String& url) const {
-  String trimmed = url.stripWhiteSpace();
   KURL completed = completeURLWithOverride(url, m_baseURL);
 
-  bool newline = trimmed.contains('\n') || trimmed.contains('\r');
-  bool lessThan = trimmed.contains('<');
-  if ((newline || lessThan) && completed.protocolIsInHTTPFamily()) {
-    if (newline) {
+  if (completed.whitespaceRemoved()) {
+    if (completed.protocolIsInHTTPFamily()) {
       UseCounter::count(*this,
                         UseCounter::DocumentCompleteURLHTTPContainingNewline);
-    }
-    if (lessThan) {
-      UseCounter::count(*this,
-                        UseCounter::DocumentCompleteURLHTTPContainingLessThan);
-    }
-    if (newline && lessThan) {
-      UseCounter::count(
-          *this,
-          UseCounter::DocumentCompleteURLHTTPContainingNewlineAndLessThan);
+      bool lessThan = url.contains('<');
+      if (lessThan) {
+        UseCounter::count(
+            *this,
+            UseCounter::DocumentCompleteURLHTTPContainingNewlineAndLessThan);
 
-      if (RuntimeEnabledFeatures::restrictCompleteURLCharacterSetEnabled())
-        return KURL();
+        if (RuntimeEnabledFeatures::restrictCompleteURLCharacterSetEnabled())
+          return KURL();
+      }
+    } else {
+      UseCounter::count(
+          *this, UseCounter::DocumentCompleteURLNonHTTPContainingNewline);
     }
-  } else if (newline || lessThan) {
-    UseCounter::count(
-        *this,
-        UseCounter::DocumentCompleteURLNonHTTPContainingNewlineOrLessThan);
   }
-  return completeURLWithOverride(url, m_baseURL);
+  return completed;
 }
 
 KURL Document::completeURLWithOverride(const String& url,

diff --git a/third_party/WebKit/Source/core/fileapi/File.h b/third_party/WebKit/Source/core/fileapi/File.h
index 4dc77f63..481fc1e 100644
--- a/third_party/WebKit/Source/core/fileapi/File.h
+++ b/third_party/WebKit/Source/core/fileapi/File.h

@@ -216,7 +216,7 @@
   // If the modification time isn't known, the current time is returned.
   double lastModifiedMS() const;
 
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
   // Instances backed by a file must have an empty file system URL.
   bool hasValidFileSystemURL() const {
     return !hasBackingFile() || m_fileSystemURL.isEmpty();

diff --git a/third_party/WebKit/Source/core/frame/EventHandlerRegistry.cpp b/third_party/WebKit/Source/core/frame/EventHandlerRegistry.cpp
index c02a63b..ce6dc461 100644
--- a/third_party/WebKit/Source/core/frame/EventHandlerRegistry.cpp
+++ b/third_party/WebKit/Source/core/frame/EventHandlerRegistry.cpp

@@ -59,7 +59,7 @@
     // the pointer events never block scrolling and the compositor
     // only needs to know about the touch listeners.
     *result = TouchStartOrMoveEventPassive;
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
   } else if (eventType == EventTypeNames::load ||
              eventType == EventTypeNames::mousemove ||
              eventType == EventTypeNames::touchstart) {
@@ -224,7 +224,7 @@
               hasEventHandlers(TouchEndOrCancelEventBlocking),
               hasEventHandlers(TouchEndOrCancelEventPassive)));
       break;
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
     case EventsForTesting:
       break;
 #endif
@@ -297,7 +297,7 @@
 }
 
 void EventHandlerRegistry::checkConsistency() const {
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
   for (size_t i = 0; i < EventHandlerClassCount; ++i) {
     EventHandlerClass handlerClass = static_cast<EventHandlerClass>(i);
     const EventTargetSet* targets = &m_targets[handlerClass];
@@ -316,7 +316,7 @@
       }
     }
   }
-#endif  // ENABLE(ASSERT)
+#endif  // DCHECK_IS_ON()
 }
 
 }  // namespace blink

diff --git a/third_party/WebKit/Source/core/frame/EventHandlerRegistry.h b/third_party/WebKit/Source/core/frame/EventHandlerRegistry.h
index 94cd9ab..fd23b1a 100644
--- a/third_party/WebKit/Source/core/frame/EventHandlerRegistry.h
+++ b/third_party/WebKit/Source/core/frame/EventHandlerRegistry.h

@@ -36,7 +36,7 @@
     TouchStartOrMoveEventPassive,
     TouchEndOrCancelEventBlocking,
     TouchEndOrCancelEventPassive,
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
     // Additional event categories for verifying handler tracking logic.
     EventsForTesting,
 #endif

diff --git a/third_party/WebKit/Source/core/frame/FrameHost.cpp b/third_party/WebKit/Source/core/frame/FrameHost.cpp
index 9ca7e6d..ac2dae81 100644
--- a/third_party/WebKit/Source/core/frame/FrameHost.cpp
+++ b/third_party/WebKit/Source/core/frame/FrameHost.cpp

@@ -173,7 +173,7 @@
   visitor->trace(m_globalRootScrollerController);
 }
 
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
 void checkFrameCountConsistency(int expectedFrameCount, Frame* frame) {
   ASSERT(expectedFrameCount >= 0);
 
@@ -186,7 +186,7 @@
 #endif
 
 int FrameHost::subframeCount() const {
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
   checkFrameCountConsistency(m_subframeCount + 1, m_page->mainFrame());
 #endif
   return m_subframeCount;

diff --git a/third_party/WebKit/Source/core/frame/FrameView.cpp b/third_party/WebKit/Source/core/frame/FrameView.cpp
index 9985fcf..440e4e3 100644
--- a/third_party/WebKit/Source/core/frame/FrameView.cpp
+++ b/third_party/WebKit/Source/core/frame/FrameView.cpp

@@ -178,9 +178,6 @@
       m_layoutSizeFixedToFrameSize(true),
       m_didScrollTimer(this, &FrameView::didScrollTimerFired),
       m_needsUpdateWidgetGeometries(false),
-#if ENABLE(ASSERT)
-      m_hasBeenDisposed(false),
-#endif
       m_horizontalScrollbarMode(ScrollbarAuto),
       m_verticalScrollbarMode(ScrollbarAuto),
       m_horizontalScrollbarLock(false),
@@ -369,7 +366,7 @@
   if (ownerElement && ownerElement->ownedWidget() == this)
     ownerElement->setWidget(nullptr);
 
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
   m_hasBeenDisposed = true;
 #endif
 }

diff --git a/third_party/WebKit/Source/core/frame/FrameView.h b/third_party/WebKit/Source/core/frame/FrameView.h
index 983b3282..0dcff6e5 100644
--- a/third_party/WebKit/Source/core/frame/FrameView.h
+++ b/third_party/WebKit/Source/core/frame/FrameView.h

@@ -1091,9 +1091,9 @@
 
   bool m_needsUpdateWidgetGeometries;
 
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
   // Verified when finalizing.
-  bool m_hasBeenDisposed;
+  bool m_hasBeenDisposed = false;
 #endif
 
   ScrollbarMode m_horizontalScrollbarMode;

diff --git a/third_party/WebKit/Source/core/frame/LocalFrame.cpp b/third_party/WebKit/Source/core/frame/LocalFrame.cpp
index 1d711cb..8cff473 100644
--- a/third_party/WebKit/Source/core/frame/LocalFrame.cpp
+++ b/third_party/WebKit/Source/core/frame/LocalFrame.cpp

@@ -179,7 +179,7 @@
   DraggedNodeImageBuilder(const LocalFrame& localFrame, Node& node)
       : m_localFrame(&localFrame),
         m_node(&node)
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
         ,
         m_domTreeVersion(node.document().domTreeVersion())
 #endif
@@ -189,7 +189,7 @@
   }
 
   ~DraggedNodeImageBuilder() {
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
     DCHECK_EQ(m_domTreeVersion, m_node->document().domTreeVersion());
 #endif
     for (Node& descendant : NodeTraversal::inclusiveDescendantsOf(*m_node))
@@ -197,7 +197,7 @@
   }
 
   std::unique_ptr<DragImage> createImage() {
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
     DCHECK_EQ(m_domTreeVersion, m_node->document().domTreeVersion());
 #endif
     // Construct layout object for |m_node| with pseudo class "-webkit-drag"
@@ -236,7 +236,7 @@
  private:
   const Member<const LocalFrame> m_localFrame;
   const Member<Node> m_node;
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
   const uint64_t m_domTreeVersion;
 #endif
 };

diff --git a/third_party/WebKit/Source/core/frame/SuspendableTimer.cpp b/third_party/WebKit/Source/core/frame/SuspendableTimer.cpp
index 595a0726..31bf39f 100644
--- a/third_party/WebKit/Source/core/frame/SuspendableTimer.cpp
+++ b/third_party/WebKit/Source/core/frame/SuspendableTimer.cpp

@@ -40,10 +40,6 @@
       SuspendableObject(context),
       m_nextFireInterval(kNextFireIntervalInvalid),
       m_repeatInterval(0)
-#if ENABLE(ASSERT)
-      ,
-      m_suspended(false)
-#endif
 {
   DCHECK(context);
 }
@@ -60,7 +56,7 @@
 }
 
 void SuspendableTimer::suspend() {
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
   ASSERT(!m_suspended);
   m_suspended = true;
 #endif
@@ -73,7 +69,7 @@
 }
 
 void SuspendableTimer::resume() {
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
   ASSERT(m_suspended);
   m_suspended = false;
 #endif

diff --git a/third_party/WebKit/Source/core/frame/SuspendableTimer.h b/third_party/WebKit/Source/core/frame/SuspendableTimer.h
index b2803f4..d33a876 100644
--- a/third_party/WebKit/Source/core/frame/SuspendableTimer.h
+++ b/third_party/WebKit/Source/core/frame/SuspendableTimer.h

@@ -51,8 +51,8 @@
 
   double m_nextFireInterval;
   double m_repeatInterval;
-#if ENABLE(ASSERT)
-  bool m_suspended;
+#if DCHECK_IS_ON()
+  bool m_suspended = false;
 #endif
 };
 

diff --git a/third_party/WebKit/Source/core/frame/UseCounter.h b/third_party/WebKit/Source/core/frame/UseCounter.h
index 2d1a149..1d02024 100644
--- a/third_party/WebKit/Source/core/frame/UseCounter.h
+++ b/third_party/WebKit/Source/core/frame/UseCounter.h

@@ -1427,9 +1427,8 @@
     V8PromiseConstructorReturnedUndefined = 1766,
     FormSubmittedWithUnclosedFormControl = 1767,
     DocumentCompleteURLHTTPContainingNewline = 1768,
-    DocumentCompleteURLHTTPContainingLessThan = 1769,
     DocumentCompleteURLHTTPContainingNewlineAndLessThan = 1770,
-    DocumentCompleteURLNonHTTPContainingNewlineOrLessThan = 1771,
+    DocumentCompleteURLNonHTTPContainingNewline = 1771,
     CSSSelectorInternalMediaControlsTextTrackList = 1772,
     CSSSelectorInternalMediaControlsTextTrackListItem = 1773,
     CSSSelectorInternalMediaControlsTextTrackListItemInput = 1774,

diff --git a/third_party/WebKit/Source/core/html/parser/BackgroundHTMLInputStream.h b/third_party/WebKit/Source/core/html/parser/BackgroundHTMLInputStream.h
index 520c240..7749f61aa 100644
--- a/third_party/WebKit/Source/core/html/parser/BackgroundHTMLInputStream.h
+++ b/third_party/WebKit/Source/core/html/parser/BackgroundHTMLInputStream.h

@@ -69,7 +69,7 @@
     size_t numberOfSegmentsAlreadyAppended;
     size_t tokensExtractedSincePreviousCheckpoint;
 
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
     bool isNull() const {
       return input.isEmpty() && !numberOfSegmentsAlreadyAppended;
     }

diff --git a/third_party/WebKit/Source/core/html/parser/BackgroundHTMLParser.cpp b/third_party/WebKit/Source/core/html/parser/BackgroundHTMLParser.cpp
index 2c9759f..fd08697 100644
--- a/third_party/WebKit/Source/core/html/parser/BackgroundHTMLParser.cpp
+++ b/third_party/WebKit/Source/core/html/parser/BackgroundHTMLParser.cpp

@@ -64,7 +64,7 @@
 
 using namespace HTMLNames;
 
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
 
 static void checkThatTokensAreSafeToSendToAnotherThread(
     const CompactHTMLTokenStream* tokens) {
@@ -319,7 +319,7 @@
   if (m_pendingTokens->isEmpty())
     return false;
 
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
   checkThatTokensAreSafeToSendToAnotherThread(m_pendingTokens.get());
   checkThatPreloadsAreSafeToSendToAnotherThread(m_pendingPreloads);
   checkThatXSSInfosAreSafeToSendToAnotherThread(m_pendingXSSInfos);

diff --git a/third_party/WebKit/Source/core/html/parser/HTMLToken.h b/third_party/WebKit/Source/core/html/parser/HTMLToken.h
index 907b1fd3..10e70ed 100644
--- a/third_party/WebKit/Source/core/html/parser/HTMLToken.h
+++ b/third_party/WebKit/Source/core/html/parser/HTMLToken.h

@@ -86,7 +86,7 @@
       static constexpr int kInvalidOffset = -1;
 
       inline void clear() {
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
         start = kInvalidOffset;
         end = kInvalidOffset;
 #endif

diff --git a/third_party/WebKit/Source/core/html/parser/HTMLTreeBuilder.cpp b/third_party/WebKit/Source/core/html/parser/HTMLTreeBuilder.cpp
index b7cec906..ce80c79 100644
--- a/third_party/WebKit/Source/core/html/parser/HTMLTreeBuilder.cpp
+++ b/third_party/WebKit/Source/core/html/parser/HTMLTreeBuilder.cpp

@@ -220,9 +220,6 @@
                                  ParserContentPolicy parserContentPolicy,
                                  const HTMLParserOptions& options)
     : m_framesetOk(true),
-#if ENABLE(ASSERT)
-      m_isAttached(true),
-#endif
       m_tree(parser->reentryPermit(), document, parserContentPolicy),
       m_insertionMode(InitialMode),
       m_originalInsertionMode(InitialMode),
@@ -283,7 +280,7 @@
 }
 
 void HTMLTreeBuilder::detach() {
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
   // This call makes little sense in fragment mode, but for consistency
   // DocumentParser expects detach() to always be called before it's destroyed.
   m_isAttached = false;

diff --git a/third_party/WebKit/Source/core/html/parser/HTMLTreeBuilder.h b/third_party/WebKit/Source/core/html/parser/HTMLTreeBuilder.h
index 216416f..14efa78 100644
--- a/third_party/WebKit/Source/core/html/parser/HTMLTreeBuilder.h
+++ b/third_party/WebKit/Source/core/html/parser/HTMLTreeBuilder.h

@@ -245,8 +245,8 @@
 
   // https://html.spec.whatwg.org/#frameset-ok-flag
   bool m_framesetOk;
-#if ENABLE(ASSERT)
-  bool m_isAttached;
+#if DCHECK_IS_ON()
+  bool m_isAttached = true;
 #endif
   FragmentParsingContext m_fragmentContext;
   HTMLConstructionSite m_tree;

diff --git a/third_party/WebKit/Source/core/layout/FloatingObjects.cpp b/third_party/WebKit/Source/core/layout/FloatingObjects.cpp
index 096621c..fa37c00 100644
--- a/third_party/WebKit/Source/core/layout/FloatingObjects.cpp
+++ b/third_party/WebKit/Source/core/layout/FloatingObjects.cpp

@@ -527,7 +527,7 @@
   if (m_placedFloatsTree.isInitialized())
     m_placedFloatsTree.add(intervalForFloatingObject(floatingObject));
 
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
   floatingObject.setIsInPlacedTree(true);
 #endif
   markLowestFloatLogicalBottomCacheAsDirty();
@@ -543,7 +543,7 @@
   }
 
   floatingObject.setIsPlaced(false);
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
   floatingObject.setIsInPlacedTree(false);
 #endif
   markLowestFloatLogicalBottomCacheAsDirty();

diff --git a/third_party/WebKit/Source/core/layout/FloatingObjects.h b/third_party/WebKit/Source/core/layout/FloatingObjects.h
index 7b213ee..c838dd1 100644
--- a/third_party/WebKit/Source/core/layout/FloatingObjects.h
+++ b/third_party/WebKit/Source/core/layout/FloatingObjects.h

@@ -108,7 +108,7 @@
     return m_frameRect;
   }
 
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
   bool isInPlacedTree() const { return m_isInPlacedTree; }
   void setIsInPlacedTree(bool value) { m_isInPlacedTree = value; }
 #endif
@@ -150,7 +150,7 @@
   unsigned m_isDescendant : 1;
   unsigned m_isPlaced : 1;
   unsigned m_isLowestNonOverhangingFloatInChild : 1;
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
   unsigned m_isInPlacedTree : 1;
 #endif
 };

diff --git a/third_party/WebKit/Source/core/layout/LayoutBlock.cpp b/third_party/WebKit/Source/core/layout/LayoutBlock.cpp
index 9228cfb..2f64fed7 100644
--- a/third_party/WebKit/Source/core/layout/LayoutBlock.cpp
+++ b/third_party/WebKit/Source/core/layout/LayoutBlock.cpp

@@ -2116,7 +2116,7 @@
   return true;
 }
 
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
 void LayoutBlock::checkPositionedObjectsNeedLayout() {
   if (!gPositionedDescendantsMap)
     return;

diff --git a/third_party/WebKit/Source/core/layout/LayoutBlock.h b/third_party/WebKit/Source/core/layout/LayoutBlock.h
index 82a3d60..99ff0167 100644
--- a/third_party/WebKit/Source/core/layout/LayoutBlock.h
+++ b/third_party/WebKit/Source/core/layout/LayoutBlock.h

@@ -313,7 +313,7 @@
   virtual LayoutUnit logicalRightSelectionOffset(const LayoutBlock* rootBlock,
                                                  LayoutUnit position) const;
 
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
   void checkPositionedObjectsNeedLayout();
 #endif
 

diff --git a/third_party/WebKit/Source/core/layout/LayoutBlockFlow.cpp b/third_party/WebKit/Source/core/layout/LayoutBlockFlow.cpp
index 0f6faf1..49d25e0 100644
--- a/third_party/WebKit/Source/core/layout/LayoutBlockFlow.cpp
+++ b/third_party/WebKit/Source/core/layout/LayoutBlockFlow.cpp

@@ -3356,7 +3356,7 @@
     moveChildrenTo(block, inlineRunStart, child);
   }
 
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
   for (LayoutObject* c = firstChild(); c; c = c->nextSibling())
     ASSERT(!c->isInline());
 #endif
@@ -3576,7 +3576,7 @@
                     this));
             floatingObject.originatingLine()->markDirty();
           }
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
           floatingObject.setOriginatingLine(nullptr);
 #endif
         }

diff --git a/third_party/WebKit/Source/core/layout/LayoutBox.cpp b/third_party/WebKit/Source/core/layout/LayoutBox.cpp
index 9ef610e..882eadf 100644
--- a/third_party/WebKit/Source/core/layout/LayoutBox.cpp
+++ b/third_party/WebKit/Source/core/layout/LayoutBox.cpp

@@ -2444,7 +2444,7 @@
 }
 
 static float getMaxWidthListMarker(const LayoutBox* layoutObject) {
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
   ASSERT(layoutObject);
   Node* parentNode = layoutObject->generatingNode();
   ASSERT(parentNode);

diff --git a/third_party/WebKit/Source/core/layout/LayoutGeometryMap.cpp b/third_party/WebKit/Source/core/layout/LayoutGeometryMap.cpp
index ee0f643b..6c02660 100644
--- a/third_party/WebKit/Source/core/layout/LayoutGeometryMap.cpp
+++ b/third_party/WebKit/Source/core/layout/LayoutGeometryMap.cpp

@@ -62,7 +62,7 @@
   }
 
   bool inFixed = false;
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
   bool foundAncestor = !ancestor || (m_mapping.size() &&
                                      m_mapping[0].m_layoutObject == ancestor);
 #endif
@@ -73,7 +73,7 @@
     // If container is the root LayoutView (step 0) we want to apply its fixed
     // position offset.
     if (i > 0 && currentStep.m_layoutObject == ancestor) {
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
       foundAncestor = true;
 #endif
       break;
@@ -153,7 +153,7 @@
     result = transformState.lastPlanarQuad();
   }
 
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
   if (m_mapping.size() > 0) {
     const LayoutObject* lastLayoutObject = m_mapping.back().m_layoutObject;
 
@@ -364,7 +364,7 @@
   }
 }
 
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
 bool LayoutGeometryMap::isTopmostLayoutView(
     const LayoutObject* layoutObject) const {
   if (!layoutObject->isLayoutView())

diff --git a/third_party/WebKit/Source/core/layout/LayoutGeometryMap.h b/third_party/WebKit/Source/core/layout/LayoutGeometryMap.h
index d95e00c..17cc9b75 100644
--- a/third_party/WebKit/Source/core/layout/LayoutGeometryMap.h
+++ b/third_party/WebKit/Source/core/layout/LayoutGeometryMap.h

@@ -105,7 +105,7 @@
   void dumpSteps() const;
 #endif
 
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
   bool isTopmostLayoutView(const LayoutObject*) const;
 #endif
 

diff --git a/third_party/WebKit/Source/core/layout/LayoutGrid.cpp b/third_party/WebKit/Source/core/layout/LayoutGrid.cpp
index bd8979a..7a9dd5b0 100644
--- a/third_party/WebKit/Source/core/layout/LayoutGrid.cpp
+++ b/third_party/WebKit/Source/core/layout/LayoutGrid.cpp

@@ -105,7 +105,7 @@
   m_gridItemsIndexesMap.set(&item, order);
 }
 
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
 bool LayoutGrid::Grid::hasAnyGridItemPaintOrder() const {
   return !m_gridItemsIndexesMap.isEmpty();
 }
@@ -836,7 +836,7 @@
   minIntrinsicSize += totalGuttersSize;
   maxIntrinsicSize += totalGuttersSize;
 
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
   DCHECK(tracksAreWiderThanMinTrackBreadth(direction, sizingData));
 #endif
 }
@@ -1922,7 +1922,7 @@
             : std::max(track->plannedSize(), track->sizeDuringDistribution()));
 }
 
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
 bool LayoutGrid::tracksAreWiderThanMinTrackBreadth(
     GridTrackSizingDirection direction,
     GridSizingData& sizingData) const {
@@ -2100,7 +2100,7 @@
 
   Vector<LayoutBox*> autoMajorAxisAutoGridItems;
   Vector<LayoutBox*> specifiedMajorAxisAutoGridItems;
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
   DCHECK(!grid.hasAnyGridItemPaintOrder());
 #endif
   DCHECK(!grid.hasAnyOrthogonalGridItem());
@@ -2136,7 +2136,7 @@
   }
   grid.setHasAnyOrthogonalGridItem(hasAnyOrthogonalGridItem);
 
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
   if (grid.hasGridItems()) {
     DCHECK_GE(grid.numTracks(ForRows),
               GridPositionsResolver::explicitGridRowCount(
@@ -2157,7 +2157,7 @@
 
   grid.setNeedsItemsPlacement(false);
 
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
   for (LayoutBox* child = grid.orderIterator().first(); child;
        child = grid.orderIterator().next()) {
     if (child->isOutOfFlowPositioned())
@@ -2564,7 +2564,7 @@
     updateAutoMarginsInRowAxisIfNeeded(*child);
 
     const GridArea& area = sizingData.grid().gridItemArea(*child);
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
     ASSERT(area.columns.startLine() < sizingData.columnTracks.size());
     ASSERT(area.rows.startLine() < sizingData.rowTracks.size());
 #endif

diff --git a/third_party/WebKit/Source/core/layout/LayoutGrid.h b/third_party/WebKit/Source/core/layout/LayoutGrid.h
index d491a58..8edfa093 100644
--- a/third_party/WebKit/Source/core/layout/LayoutGrid.h
+++ b/third_party/WebKit/Source/core/layout/LayoutGrid.h

@@ -320,7 +320,7 @@
   int inlineBlockBaseline(LineDirectionMode) const override;
   bool isInlineBaselineAlignedChild(const LayoutBox* child) const;
 
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
   bool tracksAreWiderThanMinTrackBreadth(GridTrackSizingDirection,
                                          GridSizingData&) const;
 #endif
@@ -398,7 +398,7 @@
     void setNeedsItemsPlacement(bool);
     bool needsItemsPlacement() const { return m_needsItemsPlacement; };
 
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
     bool hasAnyGridItemPaintOrder() const;
 #endif
 

diff --git a/third_party/WebKit/Source/core/layout/LayoutMedia.cpp b/third_party/WebKit/Source/core/layout/LayoutMedia.cpp
index 2382c008..0c884a8 100644
--- a/third_party/WebKit/Source/core/layout/LayoutMedia.cpp
+++ b/third_party/WebKit/Source/core/layout/LayoutMedia.cpp

@@ -60,12 +60,12 @@
 // out before the text track container. This is to ensure that the text
 // track rendering has an up-to-date position of the media controls for
 // overlap checking, see LayoutVTTCue.
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
   bool seenTextTrackContainer = false;
 #endif
   for (LayoutObject* child = m_children.lastChild(); child;
        child = child->previousSibling()) {
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
     if (child->node()->isMediaControls())
       ASSERT(!seenTextTrackContainer);
     else if (child->node()->isTextTrackContainer())

diff --git a/third_party/WebKit/Source/core/layout/LayoutMultiColumnFlowThread.cpp b/third_party/WebKit/Source/core/layout/LayoutMultiColumnFlowThread.cpp
index 8466376..434e957 100644
--- a/third_party/WebKit/Source/core/layout/LayoutMultiColumnFlowThread.cpp
+++ b/third_party/WebKit/Source/core/layout/LayoutMultiColumnFlowThread.cpp

@@ -139,7 +139,7 @@
   }
   if (!object)
     return nullptr;
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
   // Make sure that we didn't stumble into an inner multicol container.
   for (LayoutObject* walker = object->parent(); walker && walker != flowThread;
        walker = walker->parent())
@@ -188,7 +188,7 @@
   }
   if (!object || object == flowThread)
     return nullptr;
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
   // Make sure that we didn't stumble into an inner multicol container.
   for (LayoutObject* walker = object->parent(); walker && walker != flowThread;
        walker = walker->parent())

diff --git a/third_party/WebKit/Source/core/layout/LayoutTableCell.h b/third_party/WebKit/Source/core/layout/LayoutTableCell.h
index 984f98fc..e3d500a 100644
--- a/third_party/WebKit/Source/core/layout/LayoutTableCell.h
+++ b/third_party/WebKit/Source/core/layout/LayoutTableCell.h

@@ -278,7 +278,7 @@
     return style()->borderEnd();
   }
 
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
   bool isFirstOrLastCellInRow() const {
     return !table()->cellAfter(this) || !table()->cellBefore(this);
   }

diff --git a/third_party/WebKit/Source/core/layout/LayoutTableSection.cpp b/third_party/WebKit/Source/core/layout/LayoutTableSection.cpp
index 9bf28ba..e7e3bd17 100644
--- a/third_party/WebKit/Source/core/layout/LayoutTableSection.cpp
+++ b/third_party/WebKit/Source/core/layout/LayoutTableSection.cpp

@@ -1267,7 +1267,7 @@
   m_overflow.reset();
   m_overflowingCells.clear();
   m_forceSlowPaintPathWithOverflowingCell = false;
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
   bool hasOverflowingCell = false;
 #endif
   // Now that our height has been determined, add in overflow from cells.
@@ -1280,7 +1280,7 @@
       if (r < totalRows - 1 && cell == primaryCellAt(r + 1, c))
         continue;
       addOverflowFromChild(cell);
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
       hasOverflowingCell |= cell->hasVisualOverflow();
 #endif
       if (cell->hasVisualOverflow() &&

diff --git a/third_party/WebKit/Source/core/layout/LayoutText.cpp b/third_party/WebKit/Source/core/layout/LayoutText.cpp
index 0aae54a30..8920eab 100644
--- a/third_party/WebKit/Source/core/layout/LayoutText.cpp
+++ b/third_party/WebKit/Source/core/layout/LayoutText.cpp

@@ -174,7 +174,7 @@
   view()->frameView()->incrementVisuallyNonEmptyCharacterCount(m_text.length());
 }
 
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
 
 LayoutText::~LayoutText() {
   ASSERT(!m_firstTextBox);
@@ -1949,7 +1949,7 @@
   return len;
 }
 
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
 
 void LayoutText::checkConsistency() const {
 #ifdef CHECK_CONSISTENCY

diff --git a/third_party/WebKit/Source/core/layout/LayoutText.h b/third_party/WebKit/Source/core/layout/LayoutText.h
index 7b9184c..6c10d9e 100644
--- a/third_party/WebKit/Source/core/layout/LayoutText.h
+++ b/third_party/WebKit/Source/core/layout/LayoutText.h

@@ -72,7 +72,7 @@
   // not the content of the Text node, updating text-transform property
   // doesn't re-transform the string.
   LayoutText(Node*, PassRefPtr<StringImpl>);
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
   ~LayoutText() override;
 #endif
 
@@ -343,7 +343,7 @@
 
 DEFINE_LAYOUT_OBJECT_TYPE_CASTS(LayoutText, isText());
 
-#if !ENABLE(ASSERT)
+#if !DCHECK_IS_ON()
 inline void LayoutText::checkConsistency() const {}
 #endif
 

diff --git a/third_party/WebKit/Source/core/layout/LayoutView.cpp b/third_party/WebKit/Source/core/layout/LayoutView.cpp
index a5f630b1..d550901f 100644
--- a/third_party/WebKit/Source/core/layout/LayoutView.cpp
+++ b/third_party/WebKit/Source/core/layout/LayoutView.cpp

@@ -192,12 +192,12 @@
 
   LayoutBlockFlow::layout();
 
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
   checkLayoutState();
 #endif
 }
 
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
 void LayoutView::checkLayoutState() {
   ASSERT(!m_layoutState->next());
 }
@@ -294,7 +294,7 @@
     }
   }
 
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
   checkLayoutState();
 #endif
   clearNeedsLayout();

diff --git a/third_party/WebKit/Source/core/layout/LayoutView.h b/third_party/WebKit/Source/core/layout/LayoutView.h
index 4faa7b0..0317ac1 100644
--- a/third_party/WebKit/Source/core/layout/LayoutView.h
+++ b/third_party/WebKit/Source/core/layout/LayoutView.h

@@ -257,7 +257,7 @@
                                const LayoutPoint& layerOffset) const override;
 
   void layoutContent();
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
   void checkLayoutState();
 #endif
 

diff --git a/third_party/WebKit/Source/core/layout/PaintInvalidationState.cpp b/third_party/WebKit/Source/core/layout/PaintInvalidationState.cpp
index bbf3b8a..4e53b171 100644
--- a/third_party/WebKit/Source/core/layout/PaintInvalidationState.cpp
+++ b/third_party/WebKit/Source/core/layout/PaintInvalidationState.cpp

@@ -48,10 +48,6 @@
       m_containerForAbsolutePosition(layoutView),
       m_pendingDelayedPaintInvalidations(pendingDelayedPaintInvalidations),
       m_paintingLayer(*layoutView.layer())
-#if ENABLE(ASSERT)
-      ,
-      m_didUpdateForChildren(false)
-#endif
 #ifdef CHECK_FAST_PATH_SLOW_PATH_EQUALITY
       ,
       m_canCheckFastPathSlowPathEquality(layoutView ==
@@ -99,10 +95,6 @@
       m_pendingDelayedPaintInvalidations(
           parentState.m_pendingDelayedPaintInvalidations),
       m_paintingLayer(parentState.childPaintingLayer(currentObject))
-#if ENABLE(ASSERT)
-      ,
-      m_didUpdateForChildren(false)
-#endif
 #ifdef CHECK_FAST_PATH_SLOW_PATH_EQUALITY
       ,
       m_canCheckFastPathSlowPathEquality(
@@ -118,13 +110,13 @@
 // LayoutBlock::invalidatePaintOfSubtreesIfNeeded()).
 // TODO(wangxianzhu): Avoid this for
 // RuntimeEnabledFeatures::slimmingPaintInvalidationEnabled().
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
     m_didUpdateForChildren = parentState.m_didUpdateForChildren;
 #endif
     return;
   }
 
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
   DCHECK(parentState.m_didUpdateForChildren);
 #endif
 
@@ -313,7 +305,7 @@
 }
 
 void PaintInvalidationState::updateForChildren(PaintInvalidationReason reason) {
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
   DCHECK(!m_didUpdateForChildren);
   m_didUpdateForChildren = true;
 #endif
@@ -426,7 +418,7 @@
 
 LayoutPoint PaintInvalidationState::computeLocationInBacking(
     const LayoutPoint& visualRectLocation) const {
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
   DCHECK(!m_didUpdateForChildren);
 #endif
 
@@ -459,7 +451,7 @@
 }
 
 LayoutRect PaintInvalidationState::computeVisualRectInBacking() const {
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
   DCHECK(!m_didUpdateForChildren);
 #endif
 
@@ -519,7 +511,7 @@
 
 void PaintInvalidationState::mapLocalRectToPaintInvalidationContainer(
     LayoutRect& rect) const {
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
   DCHECK(!m_didUpdateForChildren);
 #endif
 

diff --git a/third_party/WebKit/Source/core/layout/PaintInvalidationState.h b/third_party/WebKit/Source/core/layout/PaintInvalidationState.h
index c887b12..46b3be9 100644
--- a/third_party/WebKit/Source/core/layout/PaintInvalidationState.h
+++ b/third_party/WebKit/Source/core/layout/PaintInvalidationState.h

@@ -170,11 +170,11 @@
 
   PaintLayer& m_paintingLayer;
 
-#if ENABLE(ASSERT)
-  bool m_didUpdateForChildren;
+#if DCHECK_IS_ON()
+  bool m_didUpdateForChildren = false;
 #endif
 
-#if ENABLE(ASSERT) && !defined(NDEBUG)
+#if DCHECK_IS_ON() && !defined(NDEBUG)
 // #define CHECK_FAST_PATH_SLOW_PATH_EQUALITY
 #endif
 

diff --git a/third_party/WebKit/Source/core/layout/TextAutosizer.cpp b/third_party/WebKit/Source/core/layout/TextAutosizer.cpp
index 48a65aec..361403e 100644
--- a/third_party/WebKit/Source/core/layout/TextAutosizer.cpp
+++ b/third_party/WebKit/Source/core/layout/TextAutosizer.cpp

@@ -301,7 +301,7 @@
 TextAutosizer::TextAutosizer(const Document* document)
     : m_document(document),
       m_firstBlockToBeginLayout(nullptr),
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
       m_blocksThatHaveBegunLayout(),
 #endif
       m_clusterStack(),
@@ -360,7 +360,7 @@
 
 TextAutosizer::BeginLayoutBehavior TextAutosizer::prepareForLayout(
     LayoutBlock* block) {
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
   m_blocksThatHaveBegunLayout.add(block);
 #endif
 
@@ -385,7 +385,7 @@
 
   if (layoutObject->isLayoutBlock()) {
     LayoutBlock* block = toLayoutBlock(layoutObject);
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
     m_blocksThatHaveBegunLayout.add(block);
 #endif
     if (Cluster* cluster = maybeCreateCluster(block))
@@ -452,7 +452,7 @@
     m_firstBlockToBeginLayout = nullptr;
     m_clusterStack.clear();
     m_stylesRetainedDuringLayout.clear();
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
     m_blocksThatHaveBegunLayout.clear();
 #endif
     // Tables can create two layout scopes for the same block so the isEmpty
@@ -1240,7 +1240,7 @@
       m_hasTableAncestor(root->isTableCell() ||
                          (m_parent && m_parent->m_hasTableAncestor)) {}
 
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
 void TextAutosizer::FingerprintMapper::assertMapsAreConsistent() {
   // For each fingerprint -> block mapping in m_blocksForFingerprint we should
   // have an associated map from block -> fingerprint in m_fingerprints.
@@ -1264,7 +1264,7 @@
   remove(layoutObject);
 
   m_fingerprints.set(layoutObject, fingerprint);
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
   assertMapsAreConsistent();
 #endif
 }
@@ -1279,7 +1279,7 @@
   if (addResult.isNewEntry)
     addResult.storedValue->value = WTF::wrapUnique(new BlockSet);
   addResult.storedValue->value->add(block);
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
   assertMapsAreConsistent();
 #endif
 }
@@ -1308,7 +1308,7 @@
       m_superclusters.remove(superclusterIter);
     }
   }
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
   assertMapsAreConsistent();
 #endif
   return true;

diff --git a/third_party/WebKit/Source/core/layout/TextAutosizer.h b/third_party/WebKit/Source/core/layout/TextAutosizer.h
index c3fb67e..0c59502 100644
--- a/third_party/WebKit/Source/core/layout/TextAutosizer.h
+++ b/third_party/WebKit/Source/core/layout/TextAutosizer.h

@@ -253,7 +253,7 @@
     // Superclusters that need to be checked for consistency at the start of the
     // next layout.
     HashSet<Supercluster*> m_potentiallyInconsistentSuperclusters;
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
     void assertMapsAreConsistent();
 #endif
   };
@@ -347,7 +347,7 @@
 
   Member<const Document> m_document;
   const LayoutBlock* m_firstBlockToBeginLayout;
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
   // Used to ensure we don't compute properties of a block before beginLayout()
   // is called on it.
   ConstBlockSet m_blocksThatHaveBegunLayout;

diff --git a/third_party/WebKit/Source/core/layout/compositing/CompositedLayerMapping.cpp b/third_party/WebKit/Source/core/layout/compositing/CompositedLayerMapping.cpp
index c8847b8e..8a87af32 100644
--- a/third_party/WebKit/Source/core/layout/compositing/CompositedLayerMapping.cpp
+++ b/third_party/WebKit/Source/core/layout/compositing/CompositedLayerMapping.cpp

@@ -2471,7 +2471,7 @@
   // FIXME: We shouldn't be called with a stale z-order lists. See bug 85512.
   parent->stackingNode()->updateLayerListsIfNeeded();
 
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
   LayerListMutationDetector mutationChecker(parent->stackingNode());
 #endif
 
@@ -3119,7 +3119,7 @@
   // ContentLayerDelegate::paintContents) try to paint throttled content.
   DocumentLifecycle::AllowThrottlingScope allowThrottling(
       m_owningLayer.layoutObject()->document().lifecycle());
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
   // FIXME: once the state machine is ready, this can be removed and we can
   // refer to that instead.
   if (Page* page = layoutObject()->frame()->page())
@@ -3197,7 +3197,7 @@
   InspectorInstrumentation::didPaint(m_owningLayer.layoutObject()->frame(),
                                      graphicsLayer, context,
                                      LayoutRect(interestRect));
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
   if (Page* page = layoutObject()->frame()->page())
     page->setIsPainting(false);
 #endif
@@ -3258,7 +3258,7 @@
   return client ? client->isTrackingRasterInvalidations() : false;
 }
 
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
 void CompositedLayerMapping::verifyNotPainting() {
   ASSERT(!layoutObject()->frame()->page() ||
          !layoutObject()->frame()->page()->isPainting());
@@ -3365,7 +3365,7 @@
   m_squashedLayers.remove(layerIndex);
 }
 
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
 bool CompositedLayerMapping::verifyLayerInSquashingVector(
     const PaintLayer* layer) {
   for (size_t layerIndex = 0; layerIndex < m_squashedLayers.size();

diff --git a/third_party/WebKit/Source/core/layout/compositing/CompositedLayerMapping.h b/third_party/WebKit/Source/core/layout/compositing/CompositedLayerMapping.h
index 1431b5d..312c9fa9 100644
--- a/third_party/WebKit/Source/core/layout/compositing/CompositedLayerMapping.h
+++ b/third_party/WebKit/Source/core/layout/compositing/CompositedLayerMapping.h

@@ -191,7 +191,7 @@
   bool updateSquashingLayerAssignment(PaintLayer* squashedLayer,
                                       size_t nextSquashedLayerIndex);
   void removeLayerFromSquashingGraphicsLayer(const PaintLayer*);
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
   bool verifyLayerInSquashingVector(const PaintLayer*);
 #endif
 
@@ -216,7 +216,7 @@
 
   bool isTrackingRasterInvalidations() const override;
 
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
   void verifyNotPainting() override;
 #endif
 
@@ -266,7 +266,7 @@
   GraphicsLayerUpdater::UpdateType updateTypeForChildren(
       GraphicsLayerUpdater::UpdateType) const;
 
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
   void assertNeedsToUpdateGraphicsLayerBitsCleared() {
     ASSERT(m_pendingUpdateScope == GraphicsLayerUpdateNone);
   }

diff --git a/third_party/WebKit/Source/core/layout/compositing/CompositingInputsUpdater.cpp b/third_party/WebKit/Source/core/layout/compositing/CompositingInputsUpdater.cpp
index 28324a3..2c1b53b 100644
--- a/third_party/WebKit/Source/core/layout/compositing/CompositingInputsUpdater.cpp
+++ b/third_party/WebKit/Source/core/layout/compositing/CompositingInputsUpdater.cpp

@@ -249,7 +249,7 @@
   m_geometryMap.popMappingsToAncestor(layer->parent());
 }
 
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
 
 void CompositingInputsUpdater::assertNeedsCompositingInputsUpdateBitsCleared(
     PaintLayer* layer) {

diff --git a/third_party/WebKit/Source/core/layout/compositing/CompositingInputsUpdater.h b/third_party/WebKit/Source/core/layout/compositing/CompositingInputsUpdater.h
index cf67d3a..5a0f189 100644
--- a/third_party/WebKit/Source/core/layout/compositing/CompositingInputsUpdater.h
+++ b/third_party/WebKit/Source/core/layout/compositing/CompositingInputsUpdater.h

@@ -21,7 +21,7 @@
 
   void update();
 
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
   static void assertNeedsCompositingInputsUpdateBitsCleared(PaintLayer*);
 #endif
 

diff --git a/third_party/WebKit/Source/core/layout/compositing/CompositingRequirementsUpdater.cpp b/third_party/WebKit/Source/core/layout/compositing/CompositingRequirementsUpdater.cpp
index ffc437e5..69a2df2 100644
--- a/third_party/WebKit/Source/core/layout/compositing/CompositingRequirementsUpdater.cpp
+++ b/third_party/WebKit/Source/core/layout/compositing/CompositingRequirementsUpdater.cpp

@@ -157,7 +157,7 @@
 };
 
 static bool requiresCompositingOrSquashing(CompositingReasons reasons) {
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
   bool fastAnswer = reasons != CompositingReasonNone;
   bool slowAnswer = requiresCompositing(reasons) || requiresSquashing(reasons);
   DCHECK_EQ(slowAnswer, fastAnswer);
@@ -379,7 +379,7 @@
     childRecursionData.m_testingOverlap = true;
   }
 
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
   LayerListMutationDetector mutationChecker(layer->stackingNode());
 #endif
 

diff --git a/third_party/WebKit/Source/core/layout/compositing/GraphicsLayerTreeBuilder.cpp b/third_party/WebKit/Source/core/layout/compositing/GraphicsLayerTreeBuilder.cpp
index cf28249..1fd04dc 100644
--- a/third_party/WebKit/Source/core/layout/compositing/GraphicsLayerTreeBuilder.cpp
+++ b/third_party/WebKit/Source/core/layout/compositing/GraphicsLayerTreeBuilder.cpp

@@ -71,7 +71,7 @@
     infoForChildren.enclosingCompositedLayer = &layer;
   }
 
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
   LayerListMutationDetector mutationChecker(layer.stackingNode());
 #endif
 

diff --git a/third_party/WebKit/Source/core/layout/compositing/GraphicsLayerUpdater.cpp b/third_party/WebKit/Source/core/layout/compositing/GraphicsLayerUpdater.cpp
index 001c0fb..b9951cb 100644
--- a/third_party/WebKit/Source/core/layout/compositing/GraphicsLayerUpdater.cpp
+++ b/third_party/WebKit/Source/core/layout/compositing/GraphicsLayerUpdater.cpp

@@ -120,7 +120,7 @@
                     layersNeedingPaintInvalidation);
 }
 
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
 
 void GraphicsLayerUpdater::assertNeedsToUpdateGraphicsLayerBitsCleared(
     PaintLayer& layer) {

diff --git a/third_party/WebKit/Source/core/layout/compositing/GraphicsLayerUpdater.h b/third_party/WebKit/Source/core/layout/compositing/GraphicsLayerUpdater.h
index 1a3aaa0a..69122d8 100644
--- a/third_party/WebKit/Source/core/layout/compositing/GraphicsLayerUpdater.h
+++ b/third_party/WebKit/Source/core/layout/compositing/GraphicsLayerUpdater.h

@@ -50,7 +50,7 @@
 
   bool needsRebuildTree() const { return m_needsRebuildTree; }
 
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
   static void assertNeedsToUpdateGraphicsLayerBitsCleared(PaintLayer&);
 #endif
 

diff --git a/third_party/WebKit/Source/core/layout/compositing/PaintLayerCompositor.cpp b/third_party/WebKit/Source/core/layout/compositing/PaintLayerCompositor.cpp
index 0938032..d649037 100644
--- a/third_party/WebKit/Source/core/layout/compositing/PaintLayerCompositor.cpp
+++ b/third_party/WebKit/Source/core/layout/compositing/PaintLayerCompositor.cpp

@@ -234,7 +234,7 @@
       scrollableArea->updateCompositorScrollAnimations();
   }
 
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
   ASSERT(lifecycle().state() == DocumentLifecycle::CompositingClean);
   assertNoUnresolvedDirtyBits();
   for (Frame* child = m_layoutView.frameView()->frame().tree().firstChild();
@@ -271,7 +271,7 @@
   rootLayer()->setNeedsCompositingInputsUpdate();
 }
 
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
 
 void PaintLayerCompositor::assertNoUnresolvedDirtyBits() {
   ASSERT(m_pendingUpdateType == CompositingUpdateNone);
@@ -325,7 +325,7 @@
   if (updateType >= CompositingUpdateAfterCompositingInputChange)
     CompositingInputsUpdater(rootLayer()).update();
 
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
   CompositingInputsUpdater::assertNeedsCompositingInputsUpdateBitsCleared(
       rootLayer());
 #endif
@@ -366,7 +366,7 @@
   if (updateType >= CompositingUpdateAfterCompositingInputChange) {
     CompositingInputsUpdater(updateRoot).update();
 
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
     // FIXME: Move this check to the end of the compositing update.
     CompositingInputsUpdater::assertNeedsCompositingInputsUpdateBitsCleared(
         updateRoot);
@@ -423,7 +423,7 @@
     if (updater.needsRebuildTree())
       updateType = std::max(updateType, CompositingUpdateRebuildTree);
 
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
     // FIXME: Move this check to the end of the compositing update.
     GraphicsLayerUpdater::assertNeedsToUpdateGraphicsLayerBitsCleared(
         *updateRoot);
@@ -1003,7 +1003,7 @@
 
 void PaintLayerCompositor::setTracksRasterInvalidations(
     bool tracksRasterInvalidations) {
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
   FrameView* view = m_layoutView.frameView();
   ASSERT(lifecycle().state() == DocumentLifecycle::PaintClean ||
          (view && view->shouldThrottleRendering()));

diff --git a/third_party/WebKit/Source/core/layout/compositing/PaintLayerCompositor.h b/third_party/WebKit/Source/core/layout/compositing/PaintLayerCompositor.h
index 3061461..2b311e82 100644
--- a/third_party/WebKit/Source/core/layout/compositing/PaintLayerCompositor.h
+++ b/third_party/WebKit/Source/core/layout/compositing/PaintLayerCompositor.h

@@ -194,7 +194,7 @@
   bool inOverlayFullscreenVideo() const { return m_inOverlayFullscreenVideo; }
 
  private:
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
   void assertNoUnresolvedDirtyBits();
 #endif
 

diff --git a/third_party/WebKit/Source/core/layout/line/InlineBox.cpp b/third_party/WebKit/Source/core/layout/line/InlineBox.cpp
index ba2aa25..97ae552 100644
--- a/third_party/WebKit/Source/core/layout/line/InlineBox.cpp
+++ b/third_party/WebKit/Source/core/layout/line/InlineBox.cpp

@@ -43,7 +43,7 @@
   void* a[4];
   LayoutPoint b;
   LayoutUnit c;
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
   bool f;
 #endif
 };
@@ -51,13 +51,11 @@
 static_assert(sizeof(InlineBox) == sizeof(SameSizeAsInlineBox),
               "InlineBox should stay small");
 
-#if ENABLE(ASSERT)
-
+#if DCHECK_IS_ON()
 InlineBox::~InlineBox() {
   if (!m_hasBadParent && m_parent)
     m_parent->setHasBadChildList();
 }
-
 #endif
 
 DISABLE_CFI_PERF

diff --git a/third_party/WebKit/Source/core/layout/line/InlineBox.h b/third_party/WebKit/Source/core/layout/line/InlineBox.h
index 244049e..16a2ed28 100644
--- a/third_party/WebKit/Source/core/layout/line/InlineBox.h
+++ b/third_party/WebKit/Source/core/layout/line/InlineBox.h

@@ -51,10 +51,6 @@
         m_parent(nullptr),
         m_lineLayoutItem(obj),
         m_logicalWidth()
-#if ENABLE(ASSERT)
-        ,
-        m_hasBadParent(false)
-#endif
   {
   }
 
@@ -76,10 +72,6 @@
         m_lineLayoutItem(item),
         m_location(topLeft),
         m_logicalWidth(logicalWidth)
-#if ENABLE(ASSERT)
-        ,
-        m_hasBadParent(false)
-#endif
   {
   }
 
@@ -333,7 +325,7 @@
                                       LayoutUnit& truncatedWidth,
                                       bool&);
 
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
   void setHasBadParent();
 #endif
 
@@ -549,16 +541,16 @@
   LayoutUnit m_logicalWidth;
 
  private:
-#if ENABLE(ASSERT)
-  bool m_hasBadParent;
+#if DCHECK_IS_ON()
+  bool m_hasBadParent = false;
 #endif
 };
 
-#if !ENABLE(ASSERT)
+#if !DCHECK_IS_ON()
 inline InlineBox::~InlineBox() {}
 #endif
 
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
 inline void InlineBox::setHasBadParent() {
   m_hasBadParent = true;
 }

diff --git a/third_party/WebKit/Source/core/layout/line/InlineFlowBox.cpp b/third_party/WebKit/Source/core/layout/line/InlineFlowBox.cpp
index 0bb27d46..a3e77bf 100644
--- a/third_party/WebKit/Source/core/layout/line/InlineFlowBox.cpp
+++ b/third_party/WebKit/Source/core/layout/line/InlineFlowBox.cpp

@@ -51,14 +51,12 @@
 static_assert(sizeof(InlineFlowBox) == sizeof(SameSizeAsInlineFlowBox),
               "InlineFlowBox should stay small");
 
-#if ENABLE(ASSERT)
-
+#if DCHECK_IS_ON()
 InlineFlowBox::~InlineFlowBox() {
   if (!m_hasBadChildList)
     for (InlineBox* child = firstChild(); child; child = child->nextOnLine())
       child->setHasBadParent();
 }
-
 #endif
 
 LayoutUnit InlineFlowBox::getFlowSpacingLogicalWidth() {
@@ -227,13 +225,13 @@
   while (child) {
     ASSERT(this == child->parent());
     next = child->nextOnLine();
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
     child->setParent(nullptr);
 #endif
     child->deleteLine();
     child = next;
   }
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
   m_firstChild = nullptr;
   m_lastChild = nullptr;
 #endif
@@ -1637,7 +1635,7 @@
 
 #endif
 
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
 void InlineFlowBox::checkConsistency() const {
 #ifdef CHECK_CONSISTENCY
   ASSERT(!m_hasBadChildList);

diff --git a/third_party/WebKit/Source/core/layout/line/InlineFlowBox.h b/third_party/WebKit/Source/core/layout/line/InlineFlowBox.h
index 3c65757..acf143bc 100644
--- a/third_party/WebKit/Source/core/layout/line/InlineFlowBox.h
+++ b/third_party/WebKit/Source/core/layout/line/InlineFlowBox.h

@@ -59,7 +59,7 @@
         m_lineBreakBidiStatusLastStrong(WTF::Unicode::LeftToRight),
         m_lineBreakBidiStatusLast(WTF::Unicode::LeftToRight),
         m_isFirstAfterPageBreak(false)
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
         ,
         m_hasBadChildList(false)
 #endif
@@ -77,7 +77,7 @@
     m_hasTextDescendants = m_hasTextChildren;
   }
 
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
   ~InlineFlowBox() override;
 #endif
 
@@ -474,7 +474,7 @@
 
 // End of RootInlineBox-specific members.
 
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
  private:
   unsigned m_hasBadChildList : 1;
 #endif
@@ -482,12 +482,12 @@
 
 DEFINE_INLINE_BOX_TYPE_CASTS(InlineFlowBox);
 
-#if !ENABLE(ASSERT)
+#if !DCHECK_IS_ON()
 inline void InlineFlowBox::checkConsistency() const {}
 #endif
 
 inline void InlineFlowBox::setHasBadChildList() {
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
   m_hasBadChildList = true;
 #endif
 }

diff --git a/third_party/WebKit/Source/core/layout/line/LineBoxList.cpp b/third_party/WebKit/Source/core/layout/line/LineBoxList.cpp
index 7938afb..77b3069d 100644
--- a/third_party/WebKit/Source/core/layout/line/LineBoxList.cpp
+++ b/third_party/WebKit/Source/core/layout/line/LineBoxList.cpp

@@ -40,7 +40,7 @@
 
 namespace blink {
 
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
 LineBoxList::~LineBoxList() {
   ASSERT(!m_firstLineBox);
   ASSERT(!m_lastLineBox);
@@ -364,7 +364,7 @@
   }
 }
 
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
 void LineBoxList::checkConsistency() const {
 #ifdef CHECK_CONSISTENCY
   const InlineFlowBox* prev = nullptr;

diff --git a/third_party/WebKit/Source/core/layout/line/LineBoxList.h b/third_party/WebKit/Source/core/layout/line/LineBoxList.h
index 788bb5cf..4ab8259f 100644
--- a/third_party/WebKit/Source/core/layout/line/LineBoxList.h
+++ b/third_party/WebKit/Source/core/layout/line/LineBoxList.h

@@ -50,7 +50,7 @@
  public:
   LineBoxList() : m_firstLineBox(nullptr), m_lastLineBox(nullptr) {}
 
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
   ~LineBoxList();
 #endif
 
@@ -100,7 +100,7 @@
   InlineFlowBox* m_lastLineBox;
 };
 
-#if !ENABLE(ASSERT)
+#if !DCHECK_IS_ON()
 inline void LineBoxList::checkConsistency() const {}
 #endif
 

diff --git a/third_party/WebKit/Source/core/layout/svg/LayoutSVGText.cpp b/third_party/WebKit/Source/core/layout/svg/LayoutSVGText.cpp
index f732e1d8..ec616f6 100644
--- a/third_party/WebKit/Source/core/layout/svg/LayoutSVGText.cpp
+++ b/third_party/WebKit/Source/core/layout/svg/LayoutSVGText.cpp

@@ -166,7 +166,7 @@
 static inline void checkDescendantTextNodeConsistency(
     LayoutSVGText& text,
     Vector<LayoutSVGInlineText*>& expectedDescendantTextNodes) {
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
   Vector<LayoutSVGInlineText*> newDescendantTextNodes;
   collectDescendantTextNodes(text, newDescendantTextNodes);
   ASSERT(newDescendantTextNodes == expectedDescendantTextNodes);

diff --git a/third_party/WebKit/Source/core/page/Page.cpp b/third_party/WebKit/Source/core/page/Page.cpp
index 50684c3..671df37 100644
--- a/third_party/WebKit/Source/core/page/Page.cpp
+++ b/third_party/WebKit/Source/core/page/Page.cpp

@@ -135,9 +135,6 @@
       m_deviceScaleFactor(1),
       m_visibilityState(PageVisibilityStateVisible),
       m_isCursorVisible(true),
-#if ENABLE(ASSERT)
-      m_isPainting(false),
-#endif
       m_frameHost(FrameHost::create(*this)) {
   ASSERT(m_editorClient);
 

diff --git a/third_party/WebKit/Source/core/page/Page.h b/third_party/WebKit/Source/core/page/Page.h
index 918050f7..133260a 100644
--- a/third_party/WebKit/Source/core/page/Page.h
+++ b/third_party/WebKit/Source/core/page/Page.h

@@ -213,7 +213,7 @@
   bool isCursorVisible() const;
   void setIsCursorVisible(bool isVisible) { m_isCursorVisible = isVisible; }
 
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
   void setIsPainting(bool painting) { m_isPainting = painting; }
   bool isPainting() const { return m_isPainting; }
 #endif
@@ -295,8 +295,8 @@
 
   bool m_isCursorVisible;
 
-#if ENABLE(ASSERT)
-  bool m_isPainting;
+#if DCHECK_IS_ON()
+  bool m_isPainting = false;
 #endif
 
   // A pointer to all the interfaces provided to in-process Frames for this

diff --git a/third_party/WebKit/Source/core/paint/PaintLayerPainter.cpp b/third_party/WebKit/Source/core/paint/PaintLayerPainter.cpp
index b2f4800..5063ae6 100644
--- a/third_party/WebKit/Source/core/paint/PaintLayerPainter.cpp
+++ b/third_party/WebKit/Source/core/paint/PaintLayerPainter.cpp

@@ -813,7 +813,7 @@
   if (!m_paintLayer.hasSelfPaintingLayerDescendant())
     return result;
 
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
   LayerListMutationDetector mutationChecker(m_paintLayer.stackingNode());
 #endif
 

diff --git a/third_party/WebKit/Source/core/paint/PaintLayerScrollableArea.h b/third_party/WebKit/Source/core/paint/PaintLayerScrollableArea.h
index 5fdb0e3..dd91069 100644
--- a/third_party/WebKit/Source/core/paint/PaintLayerScrollableArea.h
+++ b/third_party/WebKit/Source/core/paint/PaintLayerScrollableArea.h

@@ -592,7 +592,7 @@
   // MainThreadScrollingReason due to the properties of the LayoutObject
   uint32_t m_reasons;
 
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
   bool m_hasBeenDisposed;
 #endif
 };

diff --git a/third_party/WebKit/Source/core/paint/PaintLayerStackingNode.cpp b/third_party/WebKit/Source/core/paint/PaintLayerStackingNode.cpp
index a026998..55b1015 100644
--- a/third_party/WebKit/Source/core/paint/PaintLayerStackingNode.cpp
+++ b/third_party/WebKit/Source/core/paint/PaintLayerStackingNode.cpp

@@ -74,7 +74,7 @@
 }
 
 PaintLayerStackingNode::~PaintLayerStackingNode() {
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
   if (!layoutObject()->documentBeingDestroyed()) {
     DCHECK(!isInStackingParentZOrderLists());
 
@@ -100,7 +100,7 @@
 #endif
   DCHECK(isStackingContext());
 
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
   updateStackingParentForZOrderLists(0);
 #endif
 
@@ -167,7 +167,7 @@
     }
   }
 
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
   updateStackingParentForZOrderLists(this);
 #endif
 
@@ -195,7 +195,7 @@
   }
 }
 
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
 bool PaintLayerStackingNode::isInStackingParentZOrderLists() const {
   if (!m_stackingParent || m_stackingParent->zOrderListsDirty())
     return false;

diff --git a/third_party/WebKit/Source/core/paint/PaintLayerStackingNode.h b/third_party/WebKit/Source/core/paint/PaintLayerStackingNode.h
index 3eb66f98..05c043b 100644
--- a/third_party/WebKit/Source/core/paint/PaintLayerStackingNode.h
+++ b/third_party/WebKit/Source/core/paint/PaintLayerStackingNode.h

@@ -132,7 +132,7 @@
 
   PaintLayer* layer() const { return m_layer; }
 
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
   bool layerListMutationAllowed() const { return m_layerListMutationAllowed; }
   void setLayerListMutationAllowed(bool flag) {
     m_layerListMutationAllowed = flag;
@@ -161,7 +161,7 @@
       std::unique_ptr<Vector<PaintLayerStackingNode*>>& posZOrderList,
       std::unique_ptr<Vector<PaintLayerStackingNode*>>& negZOrderList);
 
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
   bool isInStackingParentZOrderLists() const;
   void updateStackingParentForZOrderLists(
       PaintLayerStackingNode* stackingParent);
@@ -199,7 +199,7 @@
   // to style change.
   bool m_isStacked : 1;
 
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
   bool m_layerListMutationAllowed : 1;
   PaintLayerStackingNode* m_stackingParent;
 #endif
@@ -208,7 +208,7 @@
 inline void PaintLayerStackingNode::clearZOrderLists() {
   DCHECK(!isStackingContext());
 
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
   updateStackingParentForZOrderLists(0);
 #endif
 
@@ -229,7 +229,7 @@
   rebuildZOrderLists();
 }
 
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
 class LayerListMutationDetector {
  public:
   explicit LayerListMutationDetector(PaintLayerStackingNode* stackingNode)

diff --git a/third_party/WebKit/Source/core/paint/SVGPaintContext.cpp b/third_party/WebKit/Source/core/paint/SVGPaintContext.cpp
index 9e9dc8a..1f2dc166 100644
--- a/third_party/WebKit/Source/core/paint/SVGPaintContext.cpp
+++ b/third_party/WebKit/Source/core/paint/SVGPaintContext.cpp

@@ -57,7 +57,7 @@
 }
 
 bool SVGPaintContext::applyClipMaskAndFilterIfNecessary() {
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
   DCHECK(!m_applyClipMaskAndFilterIfNecessaryCalled);
   m_applyClipMaskAndFilterIfNecessaryCalled = true;
 #endif

diff --git a/third_party/WebKit/Source/core/paint/SVGPaintContext.h b/third_party/WebKit/Source/core/paint/SVGPaintContext.h
index 45f80cb7..1420fc9 100644
--- a/third_party/WebKit/Source/core/paint/SVGPaintContext.h
+++ b/third_party/WebKit/Source/core/paint/SVGPaintContext.h

@@ -104,10 +104,6 @@
         m_paintInfo(paintInfo),
         m_filter(nullptr),
         m_masker(nullptr)
-#if ENABLE(ASSERT)
-        ,
-        m_applyClipMaskAndFilterIfNecessaryCalled(false)
-#endif
   {
   }
 
@@ -157,8 +153,8 @@
   Optional<ClipPathClipper> m_clipPathClipper;
   std::unique_ptr<SVGFilterRecordingContext> m_filterRecordingContext;
   Optional<ScopedPaintChunkProperties> m_scopedPaintChunkProperties;
-#if ENABLE(ASSERT)
-  bool m_applyClipMaskAndFilterIfNecessaryCalled;
+#if DCHECK_IS_ON()
+  bool m_applyClipMaskAndFilterIfNecessaryCalled = false;
 #endif
 };
 

diff --git a/third_party/WebKit/Source/core/style/GridArea.h b/third_party/WebKit/Source/core/style/GridArea.h
index 538bd0f..bbc1f97e 100644
--- a/third_party/WebKit/Source/core/style/GridArea.h
+++ b/third_party/WebKit/Source/core/style/GridArea.h

@@ -133,7 +133,7 @@
   enum GridSpanType { UntranslatedDefinite, TranslatedDefinite, Indefinite };
 
   GridSpan(int startLine, int endLine, GridSpanType type) : m_type(type) {
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
     ASSERT(startLine < endLine);
     if (type == TranslatedDefinite) {
       ASSERT(startLine >= 0);

diff --git a/third_party/WebKit/Source/core/svg/SVGDocumentExtensions.cpp b/third_party/WebKit/Source/core/svg/SVGDocumentExtensions.cpp
index d6b7b67..2314a27 100644
--- a/third_party/WebKit/Source/core/svg/SVGDocumentExtensions.cpp
+++ b/third_party/WebKit/Source/core/svg/SVGDocumentExtensions.cpp

@@ -33,10 +33,6 @@
 
 SVGDocumentExtensions::SVGDocumentExtensions(Document* document)
     : m_document(document)
-#if ENABLE(ASSERT)
-      ,
-      m_inRelativeLengthSVGRootsInvalidation(false)
-#endif
 {
 }
 
@@ -259,7 +255,7 @@
 void SVGDocumentExtensions::invalidateSVGRootsWithRelativeLengthDescendents(
     SubtreeLayoutScope* scope) {
   ASSERT(!m_inRelativeLengthSVGRootsInvalidation);
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
   AutoReset<bool> inRelativeLengthSVGRootsChange(
       &m_inRelativeLengthSVGRootsInvalidation, true);
 #endif

diff --git a/third_party/WebKit/Source/core/svg/SVGDocumentExtensions.h b/third_party/WebKit/Source/core/svg/SVGDocumentExtensions.h
index 482f8d7..7a4bce9 100644
--- a/third_party/WebKit/Source/core/svg/SVGDocumentExtensions.h
+++ b/third_party/WebKit/Source/core/svg/SVGDocumentExtensions.h

@@ -95,8 +95,8 @@
   // Root SVG elements with relative length descendants.
   HeapHashSet<Member<SVGSVGElement>> m_relativeLengthSVGRoots;
   FloatPoint m_translate;
-#if ENABLE(ASSERT)
-  bool m_inRelativeLengthSVGRootsInvalidation;
+#if DCHECK_IS_ON()
+  bool m_inRelativeLengthSVGRootsInvalidation = false;
 #endif
 
  public:

diff --git a/third_party/WebKit/Source/core/svg/SVGElement.cpp b/third_party/WebKit/Source/core/svg/SVGElement.cpp
index ca28a2c6..5ebdd6f1b 100644
--- a/third_party/WebKit/Source/core/svg/SVGElement.cpp
+++ b/third_party/WebKit/Source/core/svg/SVGElement.cpp

@@ -62,9 +62,6 @@
                        Document& document,
                        ConstructionType constructionType)
     : Element(tagName, &document, constructionType),
-#if ENABLE(ASSERT)
-      m_inRelativeLengthClientsInvalidation(false),
-#endif
       m_SVGRareData(nullptr),
       m_className(SVGAnimatedString::create(this, HTMLNames::classAttr)) {
   addToPropertyMap(m_className);
@@ -554,7 +551,7 @@
     return;
 
   ASSERT(!m_inRelativeLengthClientsInvalidation);
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
   AutoReset<bool> inRelativeLengthClientsInvalidationChange(
       &m_inRelativeLengthClientsInvalidation, true);
 #endif

diff --git a/third_party/WebKit/Source/core/svg/SVGElement.h b/third_party/WebKit/Source/core/svg/SVGElement.h
index 9edb14d3..e274cefb 100644
--- a/third_party/WebKit/Source/core/svg/SVGElement.h
+++ b/third_party/WebKit/Source/core/svg/SVGElement.h

@@ -269,8 +269,8 @@
       AttributeToPropertyMap;
   AttributeToPropertyMap m_attributeToPropertyMap;
 
-#if ENABLE(ASSERT)
-  bool m_inRelativeLengthClientsInvalidation;
+#if DCHECK_IS_ON()
+  bool m_inRelativeLengthClientsInvalidation = false;
 #endif
 
   Member<SVGElementRareData> m_SVGRareData;

diff --git a/third_party/WebKit/Source/core/svg/SVGUseElement.cpp b/third_party/WebKit/Source/core/svg/SVGUseElement.cpp
index 8e70439..ce93141f 100644
--- a/third_party/WebKit/Source/core/svg/SVGUseElement.cpp
+++ b/third_party/WebKit/Source/core/svg/SVGUseElement.cpp

@@ -103,7 +103,7 @@
   DocumentResourceClient::trace(visitor);
 }
 
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
 static inline bool isWellFormedDocument(Document* document) {
   if (document->isXMLDocument())
     return static_cast<XMLDocumentParser*>(document->parser())->wellFormed();

diff --git a/third_party/WebKit/Source/core/svg/animation/SMILTimeContainer.cpp b/third_party/WebKit/Source/core/svg/animation/SMILTimeContainer.cpp
index a9b1b9a..871201b 100644
--- a/third_party/WebKit/Source/core/svg/animation/SMILTimeContainer.cpp
+++ b/third_party/WebKit/Source/core/svg/animation/SMILTimeContainer.cpp

@@ -52,10 +52,6 @@
       m_animationPolicyOnceTimer(this,
                                  &SMILTimeContainer::animationPolicyTimerFired),
       m_ownerSVGElement(&owner)
-#if ENABLE(ASSERT)
-      ,
-      m_preventScheduledAnimationsChanges(false)
-#endif
 {
 }
 
@@ -63,7 +59,7 @@
   cancelAnimationFrame();
   cancelAnimationPolicyTimer();
   ASSERT(!m_wakeupTimer.isActive());
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
   ASSERT(!m_preventScheduledAnimationsChanges);
 #endif
 }
@@ -75,7 +71,7 @@
   DCHECK(target);
   DCHECK(animation->hasValidTarget());
 
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
   ASSERT(!m_preventScheduledAnimationsChanges);
 #endif
 
@@ -97,7 +93,7 @@
                                    const QualifiedName& attributeName) {
   ASSERT(animation->timeContainer() == this);
 
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
   ASSERT(!m_preventScheduledAnimationsChanges);
 #endif
 
@@ -233,7 +229,7 @@
   if (!isPaused())
     synchronizeToDocumentTimeline();
 
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
   m_preventScheduledAnimationsChanges = true;
 #endif
   for (const auto& entry : m_scheduledAnimations) {
@@ -244,7 +240,7 @@
     for (SVGSMILElement* element : *scheduled)
       element->reset();
   }
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
   m_preventScheduledAnimationsChanges = false;
 #endif
 
@@ -423,7 +419,7 @@
   ASSERT(document().isActive());
   SMILTime earliestFireTime = SMILTime::unresolved();
 
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
   // This boolean will catch any attempts to schedule/unschedule
   // scheduledAnimations during this critical section.  Similarly, any elements
   // removed will unschedule themselves, so this will catch modification of
@@ -491,7 +487,7 @@
   m_scheduledAnimations.removeAll(invalidKeys);
 
   if (animationsToApply.isEmpty()) {
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
     m_preventScheduledAnimationsChanges = false;
 #endif
     return earliestFireTime;
@@ -506,7 +502,7 @@
   for (const auto& timedElement : animationsToApply)
     timedElement->applyResultsToTarget();
 
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
   m_preventScheduledAnimationsChanges = false;
 #endif
 

diff --git a/third_party/WebKit/Source/core/svg/animation/SMILTimeContainer.h b/third_party/WebKit/Source/core/svg/animation/SMILTimeContainer.h
index 1b302767..dd8fb53 100644
--- a/third_party/WebKit/Source/core/svg/animation/SMILTimeContainer.h
+++ b/third_party/WebKit/Source/core/svg/animation/SMILTimeContainer.h

@@ -143,8 +143,8 @@
 
   Member<SVGSVGElement> m_ownerSVGElement;
 
-#if ENABLE(ASSERT)
-  bool m_preventScheduledAnimationsChanges;
+#if DCHECK_IS_ON()
+  bool m_preventScheduledAnimationsChanges = false;
 #endif
 };
 }  // namespace blink

diff --git a/third_party/WebKit/Source/core/workers/InProcessWorkerMessagingProxy.cpp b/third_party/WebKit/Source/core/workers/InProcessWorkerMessagingProxy.cpp
index 576c9f6e5..9c8b717b6 100644
--- a/third_party/WebKit/Source/core/workers/InProcessWorkerMessagingProxy.cpp
+++ b/third_party/WebKit/Source/core/workers/InProcessWorkerMessagingProxy.cpp

@@ -49,30 +49,6 @@
 
 namespace blink {
 
-namespace {
-
-void processUnhandledExceptionOnWorkerGlobalScope(
-    int exceptionId,
-    ExecutionContext* scriptContext) {
-  WorkerGlobalScope* globalScope = toWorkerGlobalScope(scriptContext);
-  globalScope->exceptionUnhandled(exceptionId);
-}
-
-void processMessageOnWorkerGlobalScope(
-    PassRefPtr<SerializedScriptValue> message,
-    std::unique_ptr<MessagePortChannelArray> channels,
-    InProcessWorkerObjectProxy* workerObjectProxy,
-    ExecutionContext* scriptContext) {
-  WorkerGlobalScope* globalScope = toWorkerGlobalScope(scriptContext);
-  MessagePortArray* ports =
-      MessagePort::entanglePorts(*scriptContext, std::move(channels));
-  globalScope->dispatchEvent(MessageEvent::create(ports, std::move(message)));
-  workerObjectProxy->confirmMessageFromWorkerObject();
-  workerObjectProxy->startPendingActivityTimer();
-}
-
-}  // namespace
-
 InProcessWorkerMessagingProxy::InProcessWorkerMessagingProxy(
     InProcessWorkerBase* workerObject,
     WorkerClients* workerClients)
@@ -161,17 +137,19 @@
   if (askedToTerminate())
     return;
 
-  std::unique_ptr<ExecutionContextTask> task = createCrossThreadTask(
-      &processMessageOnWorkerGlobalScope, std::move(message),
-      WTF::passed(std::move(channels)),
-      crossThreadUnretained(&workerObjectProxy()));
   if (workerThread()) {
     // A message event is an activity and may initiate another activity.
     m_workerGlobalScopeHasPendingActivity = true;
     ++m_unconfirmedMessageCount;
+    std::unique_ptr<ExecutionContextTask> task = createCrossThreadTask(
+        &InProcessWorkerObjectProxy::processMessageFromWorkerObject,
+        crossThreadUnretained(&workerObjectProxy()), std::move(message),
+        WTF::passed(std::move(channels)),
+        crossThreadUnretained(workerThread()));
     workerThread()->postTask(BLINK_FROM_HERE, std::move(task));
   } else {
-    m_queuedEarlyTasks.push_back(std::move(task));
+    m_queuedEarlyTasks.push_back(
+        WTF::makeUnique<QueuedTask>(std::move(message), std::move(channels)));
   }
 }
 
@@ -191,11 +169,15 @@
 
   ErrorEvent* event =
       ErrorEvent::create(errorMessage, location->clone(), nullptr);
-  if (m_workerObject->dispatchEvent(event) == DispatchEventResult::NotCanceled)
-    postTaskToWorkerGlobalScope(
-        BLINK_FROM_HERE,
-        createCrossThreadTask(&processUnhandledExceptionOnWorkerGlobalScope,
-                              exceptionId));
+  if (m_workerObject->dispatchEvent(event) != DispatchEventResult::NotCanceled)
+    return;
+
+  postTaskToWorkerGlobalScope(
+      BLINK_FROM_HERE,
+      createCrossThreadTask(
+          &InProcessWorkerObjectProxy::processUnhandledException,
+          crossThreadUnretained(m_workerObjectProxy.get()), exceptionId,
+          crossThreadUnretained(workerThread())));
 }
 
 void InProcessWorkerMessagingProxy::workerThreadCreated() {
@@ -207,8 +189,15 @@
 
   DCHECK_EQ(0u, m_unconfirmedMessageCount);
   m_unconfirmedMessageCount = m_queuedEarlyTasks.size();
-  for (auto& earlyTask : m_queuedEarlyTasks)
-    workerThread()->postTask(BLINK_FROM_HERE, std::move(earlyTask));
+  for (auto& queuedTask : m_queuedEarlyTasks) {
+    std::unique_ptr<ExecutionContextTask> task = createCrossThreadTask(
+        &InProcessWorkerObjectProxy::processMessageFromWorkerObject,
+        crossThreadUnretained(&workerObjectProxy()),
+        queuedTask->message.release(),
+        WTF::passed(std::move(queuedTask->channels)),
+        crossThreadUnretained(workerThread()));
+    workerThread()->postTask(BLINK_FROM_HERE, std::move(task));
+  }
   m_queuedEarlyTasks.clear();
 }
 
@@ -250,4 +239,11 @@
   return m_workerGlobalScopeHasPendingActivity;
 }
 
+InProcessWorkerMessagingProxy::QueuedTask::QueuedTask(
+    RefPtr<SerializedScriptValue> message,
+    std::unique_ptr<MessagePortChannelArray> channels)
+    : message(std::move(message)), channels(std::move(channels)) {}
+
+InProcessWorkerMessagingProxy::QueuedTask::~QueuedTask() = default;
+
 }  // namespace blink

diff --git a/third_party/WebKit/Source/core/workers/InProcessWorkerMessagingProxy.h b/third_party/WebKit/Source/core/workers/InProcessWorkerMessagingProxy.h
index ac66080..26941b7 100644
--- a/third_party/WebKit/Source/core/workers/InProcessWorkerMessagingProxy.h
+++ b/third_party/WebKit/Source/core/workers/InProcessWorkerMessagingProxy.h

@@ -98,8 +98,17 @@
   WeakPersistent<InProcessWorkerBase> m_workerObject;
   Persistent<WorkerClients> m_workerClients;
 
+  struct QueuedTask {
+    RefPtr<SerializedScriptValue> message;
+    std::unique_ptr<MessagePortChannelArray> channels;
+
+    QueuedTask(RefPtr<SerializedScriptValue> message,
+               std::unique_ptr<MessagePortChannelArray> channels);
+    ~QueuedTask();
+  };
+
   // Tasks are queued here until there's a thread object created.
-  Vector<std::unique_ptr<ExecutionContextTask>> m_queuedEarlyTasks;
+  Vector<std::unique_ptr<QueuedTask>> m_queuedEarlyTasks;
 
   // Unconfirmed messages from the parent context thread to the worker thread.
   // When this is greater than 0, |m_workerGlobalScopeHasPendingActivity| should

diff --git a/third_party/WebKit/Source/core/workers/InProcessWorkerObjectProxy.cpp b/third_party/WebKit/Source/core/workers/InProcessWorkerObjectProxy.cpp
index 338d02a..3394a64 100644
--- a/third_party/WebKit/Source/core/workers/InProcessWorkerObjectProxy.cpp
+++ b/third_party/WebKit/Source/core/workers/InProcessWorkerObjectProxy.cpp

@@ -36,6 +36,7 @@
 #include "core/dom/Document.h"
 #include "core/dom/ExecutionContext.h"
 #include "core/dom/ExecutionContextTask.h"
+#include "core/events/MessageEvent.h"
 #include "core/inspector/ConsoleMessage.h"
 #include "core/workers/InProcessWorkerMessagingProxy.h"
 #include "core/workers/ParentFrameTaskRunners.h"
@@ -43,6 +44,7 @@
 #include "core/workers/WorkerThread.h"
 #include "platform/CrossThreadFunctional.h"
 #include "platform/WebTaskRunner.h"
+#include "public/platform/Platform.h"
 #include "wtf/Functional.h"
 #include "wtf/PtrUtil.h"
 #include <memory>
@@ -74,7 +76,16 @@
                      WTF::passed(std::move(channels))));
 }
 
-void InProcessWorkerObjectProxy::confirmMessageFromWorkerObject() {
+void InProcessWorkerObjectProxy::processMessageFromWorkerObject(
+    PassRefPtr<SerializedScriptValue> message,
+    std::unique_ptr<MessagePortChannelArray> channels,
+    WorkerThread* workerThread) {
+  WorkerGlobalScope* globalScope =
+      toWorkerGlobalScope(workerThread->globalScope());
+  MessagePortArray* ports =
+      MessagePort::entanglePorts(*globalScope, std::move(channels));
+  globalScope->dispatchEvent(MessageEvent::create(ports, std::move(message)));
+
   getParentFrameTaskRunners()
       ->get(TaskType::UnspecedTimer)
       ->postTask(
@@ -82,18 +93,16 @@
           crossThreadBind(
               &InProcessWorkerMessagingProxy::confirmMessageFromWorkerObject,
               m_messagingProxyWeakPtr));
+
+  startPendingActivityTimer();
 }
 
-void InProcessWorkerObjectProxy::startPendingActivityTimer() {
-  if (m_timer->isActive()) {
-    // Reset the next interval duration to check new activity state timely.
-    // For example, a long-running activity can be cancelled by a message
-    // event.
-    m_nextIntervalInSec = kDefaultIntervalInSec;
-    return;
-  }
-  m_timer->startOneShot(m_nextIntervalInSec, BLINK_FROM_HERE);
-  m_nextIntervalInSec = std::min(m_nextIntervalInSec * 1.5, m_maxIntervalInSec);
+void InProcessWorkerObjectProxy::processUnhandledException(
+    int exceptionId,
+    WorkerThread* workerThread) {
+  WorkerGlobalScope* globalScope =
+      toWorkerGlobalScope(workerThread->globalScope());
+  globalScope->exceptionUnhandled(exceptionId);
 }
 
 void InProcessWorkerObjectProxy::reportException(
@@ -113,8 +122,9 @@
     WorkerOrWorkletGlobalScope* globalScope) {
   DCHECK(!m_workerGlobalScope);
   m_workerGlobalScope = toWorkerGlobalScope(globalScope);
-  m_timer = WTF::wrapUnique(new Timer<InProcessWorkerObjectProxy>(
-      this, &InProcessWorkerObjectProxy::checkPendingActivity));
+  m_timer = WTF::makeUnique<TaskRunnerTimer<InProcessWorkerObjectProxy>>(
+      Platform::current()->currentThread()->getWebTaskRunner(), this,
+      &InProcessWorkerObjectProxy::checkPendingActivity);
 }
 
 void InProcessWorkerObjectProxy::didEvaluateWorkerScript(bool) {
@@ -135,6 +145,18 @@
       m_nextIntervalInSec(kDefaultIntervalInSec),
       m_maxIntervalInSec(kMaxIntervalInSec) {}
 
+void InProcessWorkerObjectProxy::startPendingActivityTimer() {
+  if (m_timer->isActive()) {
+    // Reset the next interval duration to check new activity state timely.
+    // For example, a long-running activity can be cancelled by a message
+    // event.
+    m_nextIntervalInSec = kDefaultIntervalInSec;
+    return;
+  }
+  m_timer->startOneShot(m_nextIntervalInSec, BLINK_FROM_HERE);
+  m_nextIntervalInSec = std::min(m_nextIntervalInSec * 1.5, m_maxIntervalInSec);
+}
+
 void InProcessWorkerObjectProxy::checkPendingActivity(TimerBase*) {
   bool hasPendingActivity = V8GCController::hasPendingActivity(
       m_workerGlobalScope->thread()->isolate(), m_workerGlobalScope);

diff --git a/third_party/WebKit/Source/core/workers/InProcessWorkerObjectProxy.h b/third_party/WebKit/Source/core/workers/InProcessWorkerObjectProxy.h
index 5bb45db3..4ae67c8 100644
--- a/third_party/WebKit/Source/core/workers/InProcessWorkerObjectProxy.h
+++ b/third_party/WebKit/Source/core/workers/InProcessWorkerObjectProxy.h

@@ -48,6 +48,7 @@
 class ThreadedMessagingProxyBase;
 class WorkerGlobalScope;
 class WorkerOrWorkletGlobalScope;
+class WorkerThread;
 
 // A proxy to talk to the parent worker object. See class comments on
 // ThreadedObjectProxyBase.h for lifetime of this class etc.
@@ -66,8 +67,11 @@
 
   void postMessageToWorkerObject(PassRefPtr<SerializedScriptValue>,
                                  std::unique_ptr<MessagePortChannelArray>);
-  void confirmMessageFromWorkerObject();
-  void startPendingActivityTimer();
+  void processUnhandledException(int exceptionId, WorkerThread*);
+  void processMessageFromWorkerObject(
+      PassRefPtr<SerializedScriptValue> message,
+      std::unique_ptr<MessagePortChannelArray> channels,
+      WorkerThread*);
 
   // ThreadedMessagingProxyBase overrides.
   void reportException(const String& errorMessage,
@@ -86,6 +90,7 @@
  private:
   friend class InProcessWorkerMessagingProxyForTest;
 
+  void startPendingActivityTimer();
   void checkPendingActivity(TimerBase*);
 
   // No guarantees about the lifetimes of tasks posted by this proxy wrt the
@@ -95,7 +100,7 @@
 
   // Used for checking pending activities on the worker global scope. This is
   // cancelled when the worker global scope is destroyed.
-  std::unique_ptr<Timer<InProcessWorkerObjectProxy>> m_timer;
+  std::unique_ptr<TaskRunnerTimer<InProcessWorkerObjectProxy>> m_timer;
 
   // The default interval duration of the timer. This is usually
   // kDefaultIntervalInSec but made as a member variable for testing.

diff --git a/third_party/WebKit/Source/core/workers/ThreadedWorkletMessagingProxy.cpp b/third_party/WebKit/Source/core/workers/ThreadedWorkletMessagingProxy.cpp
index 25bbae9f..e70ec8f2 100644
--- a/third_party/WebKit/Source/core/workers/ThreadedWorkletMessagingProxy.cpp
+++ b/third_party/WebKit/Source/core/workers/ThreadedWorkletMessagingProxy.cpp

@@ -5,7 +5,6 @@
 #include "core/workers/ThreadedWorkletMessagingProxy.h"
 
 #include "bindings/core/v8/ScriptSourceCode.h"
-#include "bindings/core/v8/WorkerOrWorkletScriptController.h"
 #include "core/dom/Document.h"
 #include "core/dom/ExecutionContextTask.h"
 #include "core/dom/SecurityContext.h"
@@ -19,18 +18,6 @@
 
 namespace blink {
 
-namespace {
-
-void evaluateScriptOnWorkletGlobalScope(const String& source,
-                                        const KURL& scriptURL,
-                                        ExecutionContext* executionContext) {
-  WorkletGlobalScope* globalScope = toWorkletGlobalScope(executionContext);
-  globalScope->scriptController()->evaluate(
-      ScriptSourceCode(source, scriptURL));
-}
-
-}  // namespace
-
 ThreadedWorkletMessagingProxy::ThreadedWorkletMessagingProxy(
     ExecutionContext* executionContext)
     : ThreadedMessagingProxyBase(executionContext), m_weakPtrFactory(this) {
@@ -73,8 +60,10 @@
     const ScriptSourceCode& scriptSourceCode) {
   postTaskToWorkerGlobalScope(
       BLINK_FROM_HERE,
-      createCrossThreadTask(&evaluateScriptOnWorkletGlobalScope,
-                            scriptSourceCode.source(), scriptSourceCode.url()));
+      createCrossThreadTask(&ThreadedWorkletObjectProxy::evaluateScript,
+                            crossThreadUnretained(m_workletObjectProxy.get()),
+                            scriptSourceCode.source(), scriptSourceCode.url(),
+                            crossThreadUnretained(workerThread())));
 }
 
 void ThreadedWorkletMessagingProxy::terminateWorkletGlobalScope() {

diff --git a/third_party/WebKit/Source/core/workers/ThreadedWorkletObjectProxy.cpp b/third_party/WebKit/Source/core/workers/ThreadedWorkletObjectProxy.cpp
index 95af302..6fa7b14 100644
--- a/third_party/WebKit/Source/core/workers/ThreadedWorkletObjectProxy.cpp
+++ b/third_party/WebKit/Source/core/workers/ThreadedWorkletObjectProxy.cpp

@@ -4,7 +4,11 @@
 
 #include "core/workers/ThreadedWorkletObjectProxy.h"
 
+#include "bindings/core/v8/ScriptSourceCode.h"
+#include "bindings/core/v8/WorkerOrWorkletScriptController.h"
+#include "core/workers/ThreadedWorkletGlobalScope.h"
 #include "core/workers/ThreadedWorkletMessagingProxy.h"
+#include "core/workers/WorkerThread.h"
 #include "wtf/PtrUtil.h"
 #include <memory>
 
@@ -20,6 +24,15 @@
 
 ThreadedWorkletObjectProxy::~ThreadedWorkletObjectProxy() {}
 
+void ThreadedWorkletObjectProxy::evaluateScript(const String& source,
+                                                const KURL& scriptURL,
+                                                WorkerThread* workerThread) {
+  ThreadedWorkletGlobalScope* globalScope =
+      toThreadedWorkletGlobalScope(workerThread->globalScope());
+  globalScope->scriptController()->evaluate(
+      ScriptSourceCode(source, scriptURL));
+}
+
 ThreadedWorkletObjectProxy::ThreadedWorkletObjectProxy(
     const WeakPtr<ThreadedWorkletMessagingProxy>& messagingProxyWeakPtr,
     ParentFrameTaskRunners* parentFrameTaskRunners)

diff --git a/third_party/WebKit/Source/core/workers/ThreadedWorkletObjectProxy.h b/third_party/WebKit/Source/core/workers/ThreadedWorkletObjectProxy.h
index 78bbe629..78d6304 100644
--- a/third_party/WebKit/Source/core/workers/ThreadedWorkletObjectProxy.h
+++ b/third_party/WebKit/Source/core/workers/ThreadedWorkletObjectProxy.h

@@ -14,6 +14,7 @@
 namespace blink {
 
 class ThreadedWorkletMessagingProxy;
+class WorkerThread;
 
 // A proxy to talk to the parent worker object. See class comments on
 // ThreadedObjectProxyBase.h for lifetime of this class etc.
@@ -27,7 +28,9 @@
       ParentFrameTaskRunners*);
   ~ThreadedWorkletObjectProxy() override;
 
-  void reportPendingActivity(bool hasPendingActivity);
+  void evaluateScript(const String& source,
+                      const KURL& scriptURL,
+                      WorkerThread*);
 
   // ThreadedObjectProxyBase overrides.
   void reportException(const String& errorMessage,

diff --git a/third_party/WebKit/Source/core/workers/WorkerThread.cpp b/third_party/WebKit/Source/core/workers/WorkerThread.cpp
index 6b9fdb8..56fd9be0 100644
--- a/third_party/WebKit/Source/core/workers/WorkerThread.cpp
+++ b/third_party/WebKit/Source/core/workers/WorkerThread.cpp

@@ -636,8 +636,8 @@
 }
 
 bool WorkerThread::isThreadStateMutexLocked(const MutexLocker& /* unused */) {
-#if ENABLE(ASSERT)
-  // Mutex::locked() is available only if ENABLE(ASSERT) is true.
+#if DCHECK_IS_ON()
+  // Mutex::locked() is available only if DCHECK_IS_ON() is true.
   return m_threadStateMutex.locked();
 #else
   // Otherwise, believe the given MutexLocker holds |m_threadStateMutex|.

diff --git a/third_party/WebKit/Source/modules/accessibility/AXLayoutObject.cpp b/third_party/WebKit/Source/modules/accessibility/AXLayoutObject.cpp
index 13a11e8..e090fc6 100644
--- a/third_party/WebKit/Source/modules/accessibility/AXLayoutObject.cpp
+++ b/third_party/WebKit/Source/modules/accessibility/AXLayoutObject.cpp

@@ -504,7 +504,7 @@
 
 bool AXLayoutObject::computeAccessibilityIsIgnored(
     IgnoredReasons* ignoredReasons) const {
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
   ASSERT(m_initialized);
 #endif
 

diff --git a/third_party/WebKit/Source/modules/accessibility/AXNodeObject.cpp b/third_party/WebKit/Source/modules/accessibility/AXNodeObject.cpp
index 58b6cd3..8f25c79 100644
--- a/third_party/WebKit/Source/modules/accessibility/AXNodeObject.cpp
+++ b/third_party/WebKit/Source/modules/accessibility/AXNodeObject.cpp

@@ -74,9 +74,6 @@
     : AXObject(axObjectCache),
       m_ariaRole(UnknownRole),
       m_childrenDirty(false),
-#if ENABLE(ASSERT)
-      m_initialized(false),
-#endif
       m_node(node) {
 }
 
@@ -124,7 +121,7 @@
 
 bool AXNodeObject::computeAccessibilityIsIgnored(
     IgnoredReasons* ignoredReasons) const {
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
   // Double-check that an AXObject is never accessed before
   // it's been initialized.
   ASSERT(m_initialized);
@@ -741,7 +738,7 @@
 }
 
 void AXNodeObject::init() {
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
   ASSERT(!m_initialized);
   m_initialized = true;
 #endif

diff --git a/third_party/WebKit/Source/modules/accessibility/AXNodeObject.h b/third_party/WebKit/Source/modules/accessibility/AXNodeObject.h
index 327773d..80759028 100644
--- a/third_party/WebKit/Source/modules/accessibility/AXNodeObject.h
+++ b/third_party/WebKit/Source/modules/accessibility/AXNodeObject.h

@@ -55,8 +55,8 @@
   // Protected data.
   AccessibilityRole m_ariaRole;
   bool m_childrenDirty;
-#if ENABLE(ASSERT)
-  bool m_initialized;
+#if DCHECK_IS_ON()
+  bool m_initialized = false;
 #endif
 
   bool computeAccessibilityIsIgnored(IgnoredReasons* = nullptr) const override;

diff --git a/third_party/WebKit/Source/modules/accessibility/AXObjectCacheImpl.cpp b/third_party/WebKit/Source/modules/accessibility/AXObjectCacheImpl.cpp
index 6de9215..7215255 100644
--- a/third_party/WebKit/Source/modules/accessibility/AXObjectCacheImpl.cpp
+++ b/third_party/WebKit/Source/modules/accessibility/AXObjectCacheImpl.cpp

@@ -93,9 +93,6 @@
 AXObjectCacheImpl::AXObjectCacheImpl(Document& document)
     : m_document(document),
       m_modificationCount(0),
-#if ENABLE(ASSERT)
-      m_hasBeenDisposed(false),
-#endif
       m_notificationPostTimer(this,
                               &AXObjectCacheImpl::notificationPostTimerFired) {
 }
@@ -113,7 +110,7 @@
     removeAXID(obj);
   }
 
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
   m_hasBeenDisposed = true;
 #endif
 }
@@ -640,7 +637,7 @@
     if (obj->isDetached())
       continue;
 
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
     // Make sure none of the layout views are in the process of being layed out.
     // Notifications should only be sent after the layoutObject has finished
     if (obj->isAXLayoutObject()) {

diff --git a/third_party/WebKit/Source/modules/accessibility/AXObjectCacheImpl.h b/third_party/WebKit/Source/modules/accessibility/AXObjectCacheImpl.h
index 8cf8413..2f6632b 100644
--- a/third_party/WebKit/Source/modules/accessibility/AXObjectCacheImpl.h
+++ b/third_party/WebKit/Source/modules/accessibility/AXObjectCacheImpl.h

@@ -208,9 +208,9 @@
 
   HashSet<AXID> m_idsInUse;
 
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
   // Verified when finalizing.
-  bool m_hasBeenDisposed;
+  bool m_hasBeenDisposed = false;
 #endif
 
   //

diff --git a/third_party/WebKit/Source/modules/crypto/NormalizeAlgorithm.cpp b/third_party/WebKit/Source/modules/crypto/NormalizeAlgorithm.cpp
index e918899..b21a2c3 100644
--- a/third_party/WebKit/Source/modules/crypto/NormalizeAlgorithm.cpp
+++ b/third_party/WebKit/Source/modules/crypto/NormalizeAlgorithm.cpp

@@ -59,7 +59,7 @@
   unsigned char algorithmNameLength;
   WebCryptoAlgorithmId algorithmId;
 
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
   bool operator<(const AlgorithmNameMapping&) const;
 #endif
 };
@@ -91,7 +91,7 @@
                   WTF_ARRAY_LENGTH(algorithmNameMappings),
               "algorithmNameMappings needs to be updated");
 
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
 
 // Essentially std::is_sorted() (however that function is new to C++11).
 template <typename Iterator>

diff --git a/third_party/WebKit/Source/modules/indexeddb/IDBKeyPath.cpp b/third_party/WebKit/Source/modules/indexeddb/IDBKeyPath.cpp
index d27ea037..8f5e88b 100644
--- a/third_party/WebKit/Source/modules/indexeddb/IDBKeyPath.cpp
+++ b/third_party/WebKit/Source/modules/indexeddb/IDBKeyPath.cpp

@@ -106,7 +106,7 @@
 
 IDBKeyPath::IDBKeyPath(const Vector<String>& array)
     : m_type(ArrayType), m_array(array) {
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
   for (size_t i = 0; i < m_array.size(); ++i)
     ASSERT(!m_array[i].isNull());
 #endif
@@ -123,7 +123,7 @@
     ASSERT(keyPath.isStringSequence());
     m_type = ArrayType;
     m_array = keyPath.getAsStringSequence();
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
     for (size_t i = 0; i < m_array.size(); ++i)
       ASSERT(!m_array[i].isNull());
 #endif

diff --git a/third_party/WebKit/Source/modules/serviceworkers/WaitUntilObserver.cpp b/third_party/WebKit/Source/modules/serviceworkers/WaitUntilObserver.cpp
index e4839a17..f57dfb8 100644
--- a/third_party/WebKit/Source/modules/serviceworkers/WaitUntilObserver.cpp
+++ b/third_party/WebKit/Source/modules/serviceworkers/WaitUntilObserver.cpp

@@ -12,6 +12,7 @@
 #include "core/dom/ExecutionContext.h"
 #include "modules/serviceworkers/ServiceWorkerGlobalScope.h"
 #include "platform/LayoutTestSupport.h"
+#include "public/platform/Platform.h"
 #include "public/platform/modules/serviceworker/WebServiceWorkerEventResult.h"
 #include "wtf/Assertions.h"
 #include <v8.h>
@@ -137,6 +138,7 @@
       m_type(type),
       m_eventID(eventID),
       m_consumeWindowInteractionTimer(
+          Platform::current()->currentThread()->getWebTaskRunner(),
           this,
           &WaitUntilObserver::consumeWindowInteraction) {}
 

diff --git a/third_party/WebKit/Source/modules/serviceworkers/WaitUntilObserver.h b/third_party/WebKit/Source/modules/serviceworkers/WaitUntilObserver.h
index 6d5b415..910007b 100644
--- a/third_party/WebKit/Source/modules/serviceworkers/WaitUntilObserver.h
+++ b/third_party/WebKit/Source/modules/serviceworkers/WaitUntilObserver.h

@@ -71,7 +71,7 @@
   bool m_hasError = false;
   bool m_eventDispatched = false;
   double m_eventDispatchTime = 0;
-  Timer<WaitUntilObserver> m_consumeWindowInteractionTimer;
+  TaskRunnerTimer<WaitUntilObserver> m_consumeWindowInteractionTimer;
 };
 
 }  // namespace blink

diff --git a/third_party/WebKit/Source/modules/webaudio/BaseAudioContext.h b/third_party/WebKit/Source/modules/webaudio/BaseAudioContext.h
index df15848..afdf59e0 100644
--- a/third_party/WebKit/Source/modules/webaudio/BaseAudioContext.h
+++ b/third_party/WebKit/Source/modules/webaudio/BaseAudioContext.h

@@ -273,7 +273,7 @@
   void lock() { deferredTaskHandler().lock(); }
   bool tryLock() { return deferredTaskHandler().tryLock(); }
   void unlock() { deferredTaskHandler().unlock(); }
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
   // Returns true if this thread owns the context's lock.
   bool isGraphOwner() { return deferredTaskHandler().isGraphOwner(); }
 #endif

diff --git a/third_party/WebKit/Source/modules/webaudio/DeferredTaskHandler.cpp b/third_party/WebKit/Source/modules/webaudio/DeferredTaskHandler.cpp
index 17a07a7..4522c2e6 100644
--- a/third_party/WebKit/Source/modules/webaudio/DeferredTaskHandler.cpp
+++ b/third_party/WebKit/Source/modules/webaudio/DeferredTaskHandler.cpp

@@ -65,7 +65,7 @@
   m_contextGraphMutex.lock();
 }
 
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
 bool DeferredTaskHandler::isGraphOwner() {
   return m_contextGraphMutex.locked();
 }

diff --git a/third_party/WebKit/Source/modules/webaudio/DeferredTaskHandler.h b/third_party/WebKit/Source/modules/webaudio/DeferredTaskHandler.h
index 2de1cbf..4cd4909 100644
--- a/third_party/WebKit/Source/modules/webaudio/DeferredTaskHandler.h
+++ b/third_party/WebKit/Source/modules/webaudio/DeferredTaskHandler.h

@@ -128,7 +128,7 @@
   // MUST NOT be used in the real-time audio context.
   void offlineLock();
 
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
   // Returns true if this thread owns the context's lock.
   bool isGraphOwner();
 #endif

diff --git a/third_party/WebKit/Source/modules/webdatabase/Database.cpp b/third_party/WebKit/Source/modules/webdatabase/Database.cpp
index 97b4c6f7..afe9e49f 100644
--- a/third_party/WebKit/Source/modules/webdatabase/Database.cpp
+++ b/third_party/WebKit/Source/modules/webdatabase/Database.cpp

@@ -860,7 +860,7 @@
 // sometimes firing it ourselves, this code should probably be pushed down
 // into Database so that we only create the SQLTransaction if we're
 // actually going to run it.
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
   SQLTransactionErrorCallback* originalErrorCallback = errorCallback;
 #endif
   SQLTransaction* transaction = SQLTransaction::create(

diff --git a/third_party/WebKit/Source/modules/webdatabase/DatabaseManager.cpp b/third_party/WebKit/Source/modules/webdatabase/DatabaseManager.cpp
index d019b7d..abab2e2 100644
--- a/third_party/WebKit/Source/modules/webdatabase/DatabaseManager.cpp
+++ b/third_party/WebKit/Source/modules/webdatabase/DatabaseManager.cpp

@@ -64,10 +64,6 @@
 }
 
 DatabaseManager::DatabaseManager()
-#if ENABLE(ASSERT)
-    : m_databaseContextRegisteredCount(0),
-      m_databaseContextInstanceCount(0)
-#endif
 {
 }
 
@@ -98,7 +94,7 @@
     DatabaseContext* databaseContext) {
   ExecutionContext* context = databaseContext->getExecutionContext();
   m_contextMap.set(context, databaseContext);
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
   m_databaseContextRegisteredCount++;
 #endif
 }
@@ -107,13 +103,13 @@
     DatabaseContext* databaseContext) {
   ExecutionContext* context = databaseContext->getExecutionContext();
   ASSERT(m_contextMap.get(context));
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
   m_databaseContextRegisteredCount--;
 #endif
   m_contextMap.remove(context);
 }
 
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
 void DatabaseManager::didConstructDatabaseContext() {
   m_databaseContextInstanceCount++;
 }

diff --git a/third_party/WebKit/Source/modules/webdatabase/DatabaseManager.h b/third_party/WebKit/Source/modules/webdatabase/DatabaseManager.h
index 165d4617..65ee92b5 100644
--- a/third_party/WebKit/Source/modules/webdatabase/DatabaseManager.h
+++ b/third_party/WebKit/Source/modules/webdatabase/DatabaseManager.h

@@ -55,7 +55,7 @@
   void registerDatabaseContext(DatabaseContext*);
   void unregisterDatabaseContext(DatabaseContext*);
 
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
   void didConstructDatabaseContext();
   void didDestructDatabaseContext();
 #else
@@ -109,9 +109,9 @@
                                 Member<DatabaseContext>>
       ContextMap;
   ContextMap m_contextMap;
-#if ENABLE(ASSERT)
-  int m_databaseContextRegisteredCount;
-  int m_databaseContextInstanceCount;
+#if DCHECK_IS_ON()
+  int m_databaseContextRegisteredCount = 0;
+  int m_databaseContextInstanceCount = 0;
 #endif
 };
 

diff --git a/third_party/WebKit/Source/modules/webdatabase/DatabaseThread.cpp b/third_party/WebKit/Source/modules/webdatabase/DatabaseThread.cpp
index ab29b40..c928b635 100644
--- a/third_party/WebKit/Source/modules/webdatabase/DatabaseThread.cpp
+++ b/third_party/WebKit/Source/modules/webdatabase/DatabaseThread.cpp

@@ -138,7 +138,7 @@
 void DatabaseThread::recordDatabaseClosed(Database* database) {
   ASSERT(isDatabaseThread());
   ASSERT(database);
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
   {
     MutexLocker lock(m_terminationRequestedMutex);
     ASSERT(m_terminationRequested || m_openDatabaseSet.contains(database));
@@ -162,7 +162,7 @@
 
 void DatabaseThread::scheduleTask(std::unique_ptr<DatabaseTask> task) {
   ASSERT(m_thread);
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
   {
     MutexLocker lock(m_terminationRequestedMutex);
     ASSERT(!m_terminationRequested);

diff --git a/third_party/WebKit/Source/modules/webdatabase/SQLTransactionStateMachine.h b/third_party/WebKit/Source/modules/webdatabase/SQLTransactionStateMachine.h
index 77f2cfd8..e383739f 100644
--- a/third_party/WebKit/Source/modules/webdatabase/SQLTransactionStateMachine.h
+++ b/third_party/WebKit/Source/modules/webdatabase/SQLTransactionStateMachine.h

@@ -48,13 +48,13 @@
   SQLTransactionState m_nextState;
   SQLTransactionState m_requestedState;
 
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
   // The state audit trail (i.e. bread crumbs) keeps track of up to the last
   // s_sizeOfStateAuditTrail states that the state machine enters. The audit
   // trail is updated before entering each state. This is for debugging use
   // only.
   static const int s_sizeOfStateAuditTrail = 20;
-  int m_nextStateAuditEntry;
+  int m_nextStateAuditEntry = 0;
   SQLTransactionState m_stateAuditTrail[s_sizeOfStateAuditTrail];
 #endif
 };
@@ -67,12 +67,8 @@
 SQLTransactionStateMachine<T>::SQLTransactionStateMachine()
     : m_nextState(SQLTransactionState::Idle),
       m_requestedState(SQLTransactionState::Idle)
-#if ENABLE(ASSERT)
-      ,
-      m_nextStateAuditEntry(0)
-#endif
 {
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
   for (int i = 0; i < s_sizeOfStateAuditTrail; i++)
     m_stateAuditTrail[i] = SQLTransactionState::NumberOfStates;
 #endif
@@ -94,7 +90,7 @@
     StateFunction stateFunction = stateFunctionFor(m_nextState);
     ASSERT(stateFunction);
 
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
     m_stateAuditTrail[m_nextStateAuditEntry] = m_nextState;
     m_nextStateAuditEntry =
         (m_nextStateAuditEntry + 1) % s_sizeOfStateAuditTrail;

diff --git a/third_party/WebKit/Source/modules/webdatabase/sqlite/SQLiteStatement.cpp b/third_party/WebKit/Source/modules/webdatabase/sqlite/SQLiteStatement.cpp
index b7e2c33..b2ad120 100644
--- a/third_party/WebKit/Source/modules/webdatabase/sqlite/SQLiteStatement.cpp
+++ b/third_party/WebKit/Source/modules/webdatabase/sqlite/SQLiteStatement.cpp

@@ -82,10 +82,6 @@
     : m_database(db),
       m_query(sql),
       m_statement(0)
-#if ENABLE(ASSERT)
-      ,
-      m_isPrepared(false)
-#endif
 {
 }
 
@@ -127,7 +123,7 @@
   else if (*tail && **tail)
     error = SQLITE_ERROR;
 
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
   m_isPrepared = error == SQLITE_OK;
 #endif
   return restrictError(error);
@@ -156,7 +152,7 @@
 }
 
 int SQLiteStatement::finalize() {
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
   m_isPrepared = false;
 #endif
   if (!m_statement)

diff --git a/third_party/WebKit/Source/modules/webdatabase/sqlite/SQLiteStatement.h b/third_party/WebKit/Source/modules/webdatabase/sqlite/SQLiteStatement.h
index 6ae764a..77305eb 100644
--- a/third_party/WebKit/Source/modules/webdatabase/sqlite/SQLiteStatement.h
+++ b/third_party/WebKit/Source/modules/webdatabase/sqlite/SQLiteStatement.h

@@ -77,8 +77,8 @@
   SQLiteDatabase& m_database;
   String m_query;
   sqlite3_stmt* m_statement;
-#if ENABLE(ASSERT)
-  bool m_isPrepared;
+#if DCHECK_IS_ON()
+  bool m_isPrepared = false;
 #endif
 };
 

diff --git a/third_party/WebKit/Source/platform/audio/android/FFTFrameOpenMAXDLAndroid.cpp b/third_party/WebKit/Source/platform/audio/android/FFTFrameOpenMAXDLAndroid.cpp
index 36f9f78..c36dd50 100644
--- a/third_party/WebKit/Source/platform/audio/android/FFTFrameOpenMAXDLAndroid.cpp
+++ b/third_party/WebKit/Source/platform/audio/android/FFTFrameOpenMAXDLAndroid.cpp

@@ -35,7 +35,7 @@
 
 namespace blink {
 
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
 const unsigned kMaxFFTPow2Size = 15;
 #endif
 

diff --git a/third_party/WebKit/Source/platform/audio/ffmpeg/FFTFrameFFMPEG.cpp b/third_party/WebKit/Source/platform/audio/ffmpeg/FFTFrameFFMPEG.cpp
index 22175ec..64b9248a 100644
--- a/third_party/WebKit/Source/platform/audio/ffmpeg/FFTFrameFFMPEG.cpp
+++ b/third_party/WebKit/Source/platform/audio/ffmpeg/FFTFrameFFMPEG.cpp

@@ -42,7 +42,7 @@
 
 namespace blink {
 
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
 // Max FFT size for FFMPEG.  WebAudio currently only uses FFTs up to size 15
 // (2^15 points).
 const int kMaxFFTPow2Size = 16;

diff --git a/third_party/WebKit/Source/platform/fonts/FontCache.cpp b/third_party/WebKit/Source/platform/fonts/FontCache.cpp
index 64be67e..9ef8d237 100644
--- a/third_party/WebKit/Source/platform/fonts/FontCache.cpp
+++ b/third_party/WebKit/Source/platform/fonts/FontCache.cpp

@@ -285,7 +285,7 @@
   if (!gFontDataCache)
     gFontDataCache = new FontDataCache;
 
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
   if (shouldRetain == DoNotRetain)
     ASSERT(m_purgePreventCount);
 #endif

diff --git a/third_party/WebKit/Source/platform/geometry/FloatRect.cpp b/third_party/WebKit/Source/platform/geometry/FloatRect.cpp
index fe35f38..f276d2e 100644
--- a/third_party/WebKit/Source/platform/geometry/FloatRect.cpp
+++ b/third_party/WebKit/Source/platform/geometry/FloatRect.cpp

@@ -60,7 +60,7 @@
                    clampTo<float>(height));
 }
 
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
 bool FloatRect::mayNotHaveExactIntRectRepresentation() const {
   static const float maxExactlyExpressible = 1 << FLT_MANT_DIG;
   return fabs(x()) > maxExactlyExpressible ||

diff --git a/third_party/WebKit/Source/platform/geometry/FloatRect.h b/third_party/WebKit/Source/platform/geometry/FloatRect.h
index 00de1b83..779193d5 100644
--- a/third_party/WebKit/Source/platform/geometry/FloatRect.h
+++ b/third_party/WebKit/Source/platform/geometry/FloatRect.h

@@ -201,7 +201,7 @@
   }
   operator gfx::RectF() const;
 
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
   bool mayNotHaveExactIntRectRepresentation() const;
 #endif
 

diff --git a/third_party/WebKit/Source/platform/graphics/GraphicsContext.cpp b/third_party/WebKit/Source/platform/graphics/GraphicsContext.cpp
index dcb2f75..b7f8fa6 100644
--- a/third_party/WebKit/Source/platform/graphics/GraphicsContext.cpp
+++ b/third_party/WebKit/Source/platform/graphics/GraphicsContext.cpp

@@ -127,7 +127,7 @@
   m_canvas->restore();
 }
 
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
 unsigned GraphicsContext::saveCount() const {
   // Each m_paintStateStack entry implies an additional save op
   // (on top of its own saveCount), except for the first frame.

diff --git a/third_party/WebKit/Source/platform/graphics/GraphicsContext.h b/third_party/WebKit/Source/platform/graphics/GraphicsContext.h
index f99ef5b7..03c57c8 100644
--- a/third_party/WebKit/Source/platform/graphics/GraphicsContext.h
+++ b/third_party/WebKit/Source/platform/graphics/GraphicsContext.h

@@ -91,7 +91,7 @@
   void save();
   void restore();
 
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
   unsigned saveCount() const;
 #endif
 

diff --git a/third_party/WebKit/Source/platform/graphics/GraphicsLayer.cpp b/third_party/WebKit/Source/platform/graphics/GraphicsLayer.cpp
index dfe1e0da..ce29c2d 100644
--- a/third_party/WebKit/Source/platform/graphics/GraphicsLayer.cpp
+++ b/third_party/WebKit/Source/platform/graphics/GraphicsLayer.cpp

@@ -112,7 +112,7 @@
       m_renderingContext3d(0),
       m_colorBehavior(ColorBehavior::transformToGlobalTarget()),
       m_hasPreferredRasterBounds(false) {
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
   if (m_client)
     m_client->verifyNotPainting();
 #endif
@@ -134,7 +134,7 @@
     m_linkHighlights[i]->clearCurrentGraphicsLayer();
   m_linkHighlights.clear();
 
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
   if (m_client)
     m_client->verifyNotPainting();
 #endif

diff --git a/third_party/WebKit/Source/platform/graphics/GraphicsLayerClient.h b/third_party/WebKit/Source/platform/graphics/GraphicsLayerClient.h
index 1a9f4ae..2e48204 100644
--- a/third_party/WebKit/Source/platform/graphics/GraphicsLayerClient.h
+++ b/third_party/WebKit/Source/platform/graphics/GraphicsLayerClient.h

@@ -89,7 +89,7 @@
 
   virtual String debugName(const GraphicsLayer*) const = 0;
 
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
   // CompositedLayerMapping overrides this to verify that it is not
   // currently painting contents. An ASSERT fails, if it is.
   // This is executed in GraphicsLayer construction and destruction

diff --git a/third_party/WebKit/Source/platform/graphics/ImageDecodingStore.cpp b/third_party/WebKit/Source/platform/graphics/ImageDecodingStore.cpp
index 17a2e11..61aa435 100644
--- a/third_party/WebKit/Source/platform/graphics/ImageDecodingStore.cpp
+++ b/third_party/WebKit/Source/platform/graphics/ImageDecodingStore.cpp

@@ -43,7 +43,7 @@
       m_heapMemoryUsageInBytes(0) {}
 
 ImageDecodingStore::~ImageDecodingStore() {
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
   setCacheLimitInBytes(0);
   ASSERT(!m_decoderCacheMap.size());
   ASSERT(!m_orderedCacheList.size());

diff --git a/third_party/WebKit/Source/platform/graphics/Path.cpp b/third_party/WebKit/Source/platform/graphics/Path.cpp
index dd890089b..cf5baae2 100644
--- a/third_party/WebKit/Source/platform/graphics/Path.cpp
+++ b/third_party/WebKit/Source/platform/graphics/Path.cpp

@@ -549,7 +549,7 @@
   return Op(m_path, other.m_path, kIntersect_SkPathOp, &m_path);
 }
 
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
 bool ellipseIsRenderable(float startAngle, float endAngle) {
   return (std::abs(endAngle - startAngle) < twoPiFloat) ||
          WebCoreFloatNearlyEqual(std::abs(endAngle - startAngle), twoPiFloat);

diff --git a/third_party/WebKit/Source/platform/graphics/Path.h b/third_party/WebKit/Source/platform/graphics/Path.h
index d7bcc52..69429c1 100644
--- a/third_party/WebKit/Source/platform/graphics/Path.h
+++ b/third_party/WebKit/Source/platform/graphics/Path.h

@@ -202,7 +202,7 @@
   SkPath m_path;
 };
 
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
 PLATFORM_EXPORT bool ellipseIsRenderable(float startAngle, float endAngle);
 #endif
 

diff --git a/third_party/WebKit/Source/platform/graphics/paint/DisplayItemClientTest.cpp b/third_party/WebKit/Source/platform/graphics/paint/DisplayItemClientTest.cpp
index 462e5a2..59189e4d 100644
--- a/third_party/WebKit/Source/platform/graphics/paint/DisplayItemClientTest.cpp
+++ b/third_party/WebKit/Source/platform/graphics/paint/DisplayItemClientTest.cpp

@@ -10,7 +10,7 @@
 namespace blink {
 namespace {
 
-#if ENABLE(ASSERT) && !defined(UNDEFINED_SANITIZER)
+#if DCHECK_IS_ON() && !defined(UNDEFINED_SANITIZER)
 
 TEST(DisplayItemClientTest, IsAlive) {
   EXPECT_FALSE(reinterpret_cast<DisplayItemClient*>(0x12345678)->isAlive());
@@ -20,7 +20,7 @@
   EXPECT_FALSE(testClient->isAlive());
 }
 
-#endif  // ENABLE(ASSERT)
+#endif
 
 }  // namespace
 }  // namespace blink

diff --git a/third_party/WebKit/Source/platform/heap/CallbackStack.cpp b/third_party/WebKit/Source/platform/heap/CallbackStack.cpp
index 93a1232..affa37b 100644
--- a/third_party/WebKit/Source/platform/heap/CallbackStack.cpp
+++ b/third_party/WebKit/Source/platform/heap/CallbackStack.cpp

@@ -67,7 +67,7 @@
 
 CallbackStack::Block::Block(Block* next) {
   m_buffer = CallbackStackMemoryPool::instance().allocate();
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
   clear();
 #endif
 
@@ -84,7 +84,7 @@
   m_next = nullptr;
 }
 
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
 void CallbackStack::Block::clear() {
   for (size_t i = 0; i < CallbackStackMemoryPool::kBlockSize; i++)
     m_buffer[i] = Item(0, 0);
@@ -100,7 +100,7 @@
   }
 }
 
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
 bool CallbackStack::Block::hasCallbackForObject(const void* object) {
   for (unsigned i = 0; m_buffer + i < m_current; i++) {
     Item* item = &m_buffer[i];
@@ -159,7 +159,7 @@
   for (;;) {
     Block* next = m_first->next();
     if (!next) {
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
       m_first->clear();
 #endif
       return nullptr;
@@ -204,7 +204,7 @@
   return !m_first->next();
 }
 
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
 bool CallbackStack::hasCallbackForObject(const void* object) {
   for (Block* current = m_first; current; current = current->next()) {
     if (current->hasCallbackForObject(object))

diff --git a/third_party/WebKit/Source/platform/heap/CallbackStack.h b/third_party/WebKit/Source/platform/heap/CallbackStack.h
index 377c6214..b4dfd3a 100644
--- a/third_party/WebKit/Source/platform/heap/CallbackStack.h
+++ b/third_party/WebKit/Source/platform/heap/CallbackStack.h

@@ -52,7 +52,7 @@
 
   void invokeEphemeronCallbacks(Visitor*);
 
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
   bool hasCallbackForObject(const void*);
 #endif
   bool hasJustOneBlock() const;
@@ -68,7 +68,7 @@
     explicit Block(Block* next);
     ~Block();
 
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
     void clear();
 #endif
     Block* next() const { return m_next; }
@@ -92,7 +92,7 @@
 
     void invokeEphemeronCallbacks(Visitor*);
 
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
     bool hasCallbackForObject(const void*);
 #endif
 

diff --git a/third_party/WebKit/Source/platform/heap/GCInfo.cpp b/third_party/WebKit/Source/platform/heap/GCInfo.cpp
index 9092f7ec..7d2d1105c 100644
--- a/third_party/WebKit/Source/platform/heap/GCInfo.cpp
+++ b/third_party/WebKit/Source/platform/heap/GCInfo.cpp

@@ -67,7 +67,7 @@
   s_gcInfoTable = nullptr;
 }
 
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
 void assertObjectHasGCInfo(const void* payload, size_t gcInfoIndex) {
   ASSERT(HeapObjectHeader::fromPayload(payload)->checkHeader());
 #if !defined(COMPONENT_BUILD)

diff --git a/third_party/WebKit/Source/platform/heap/GCInfo.h b/third_party/WebKit/Source/platform/heap/GCInfo.h
index d68f968..1d441817 100644
--- a/third_party/WebKit/Source/platform/heap/GCInfo.h
+++ b/third_party/WebKit/Source/platform/heap/GCInfo.h

@@ -156,7 +156,7 @@
 // object header keeps its index into this table.
 extern PLATFORM_EXPORT GCInfo const** s_gcInfoTable;
 
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
 PLATFORM_EXPORT void assertObjectHasGCInfo(const void*, size_t gcInfoIndex);
 #endif
 

diff --git a/third_party/WebKit/Source/platform/heap/Heap.cpp b/third_party/WebKit/Source/platform/heap/Heap.cpp
index 7e94c56..22e5ef818 100644
--- a/third_party/WebKit/Source/platform/heap/Heap.cpp
+++ b/third_party/WebKit/Source/platform/heap/Heap.cpp

@@ -270,7 +270,7 @@
   m_safePointBarrier->resumeOthers();
 }
 
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
 BasePage* ThreadHeap::findPageFromAddress(Address address) {
   MutexLocker locker(m_threadAttachMutex);
   for (ThreadState* state : m_threads) {
@@ -293,7 +293,7 @@
 Address ThreadHeap::checkAndMarkPointer(Visitor* visitor, Address address) {
   ASSERT(ThreadState::current()->isInGC());
 
-#if !ENABLE(ASSERT)
+#if !DCHECK_IS_ON()
   if (m_heapDoesNotContainCache->lookup(address))
     return nullptr;
 #endif
@@ -307,7 +307,7 @@
     return address;
   }
 
-#if !ENABLE(ASSERT)
+#if !DCHECK_IS_ON()
   m_heapDoesNotContainCache->addEntry(address);
 #else
   if (!m_heapDoesNotContainCache->lookup(address))
@@ -393,7 +393,7 @@
   pushPostMarkingCallback(table, iterationDoneCallback);
 }
 
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
 bool ThreadHeap::weakTableRegistered(const void* table) {
   ASSERT(m_ephemeronStack);
   return m_ephemeronStack->hasCallbackForObject(table);

diff --git a/third_party/WebKit/Source/platform/heap/Heap.h b/third_party/WebKit/Source/platform/heap/Heap.h
index 846f71a0..c494896d1 100644
--- a/third_party/WebKit/Source/platform/heap/Heap.h
+++ b/third_party/WebKit/Source/platform/heap/Heap.h

@@ -234,7 +234,7 @@
   bool isMainThreadHeap() { return this == ThreadHeap::mainThreadHeap(); }
   static ThreadHeap* mainThreadHeap() { return s_mainThreadHeap; }
 
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
   bool isAtSafePoint();
   BasePage* findPageFromAddress(Address);
 #endif
@@ -378,7 +378,7 @@
   void registerWeakTable(void* containerObject,
                          EphemeronCallback,
                          EphemeronCallback);
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
   bool weakTableRegistered(const void*);
 #endif
 
@@ -590,7 +590,7 @@
 
 #define IS_EAGERLY_FINALIZED() \
   (pageFromObject(this)->arena()->arenaIndex() == BlinkGC::EagerSweepArenaIndex)
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
 class VerifyEagerFinalization {
   DISALLOW_NEW();
 

diff --git a/third_party/WebKit/Source/platform/heap/HeapAllocator.h b/third_party/WebKit/Source/platform/heap/HeapAllocator.h
index 649135b..ec391a1 100644
--- a/third_party/WebKit/Source/platform/heap/HeapAllocator.h
+++ b/third_party/WebKit/Source/platform/heap/HeapAllocator.h

@@ -180,7 +180,7 @@
                                iterationDoneCallback);
   }
 
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
   template <typename VisitorDispatcher>
   static bool weakTableRegistered(VisitorDispatcher visitor,
                                   const void* closure) {

diff --git a/third_party/WebKit/Source/platform/heap/HeapCompact.cpp b/third_party/WebKit/Source/platform/heap/HeapCompact.cpp
index 591caef56..76b9ed8 100644
--- a/third_party/WebKit/Source/platform/heap/HeapCompact.cpp
+++ b/third_party/WebKit/Source/platform/heap/HeapCompact.cpp

@@ -87,7 +87,7 @@
         blinkPageAddress(slotAddress) + blinkGuardPageSize);
     if (LIKELY(!m_relocatablePages.contains(slotPage)))
       return;
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
     DCHECK(slotPage->contains(slotAddress));
 #endif
     // Unlikely case, the slot resides on a compacting arena's page.

diff --git a/third_party/WebKit/Source/platform/heap/HeapPage.cpp b/third_party/WebKit/Source/platform/heap/HeapPage.cpp
index ad097d4..cb8f77ef 100644
--- a/third_party/WebKit/Source/platform/heap/HeapPage.cpp
+++ b/third_party/WebKit/Source/platform/heap/HeapPage.cpp

@@ -89,7 +89,7 @@
 
 namespace blink {
 
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
 NO_SANITIZE_ADDRESS
 void HeapObjectHeader::zapMagic() {
   ASSERT(checkHeader());
@@ -158,7 +158,7 @@
   allocatorDump->AddScalar("free_count", "objects", heapInfo.freeCount);
 }
 
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
 BasePage* BaseArena::findPageFromAddress(Address address) {
   for (BasePage* page = m_firstPage; page; page = page->next()) {
     if (page->contains(address))
@@ -562,7 +562,7 @@
     freedPageCount++;
     BasePage* nextPage;
     availablePages->unlink(&nextPage);
-#if !(ENABLE(ASSERT) || defined(LEAK_SANITIZER) || \
+#if !(DCHECK_IS_ON() || defined(LEAK_SANITIZER) || \
       defined(ADDRESS_SANITIZER) || defined(MEMORY_SANITIZER))
     // Clear out the page before adding it to the free page pool, which
     // decommits it. Recommitting the page must find a zeroed page later.
@@ -583,7 +583,7 @@
   heap.compaction()->finishedArenaCompaction(this, freedPageCount, freedSize);
 }
 
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
 bool NormalPageArena::isConsistentForGC() {
   // A thread heap is consistent for sweeping if none of the pages to be swept
   // contain a freelist block or the current allocation point.
@@ -662,7 +662,7 @@
   page->link(&m_firstPage);
 
   getThreadState()->heap().heapStats().increaseAllocatedSpace(page->size());
-#if ENABLE(ASSERT) || defined(LEAK_SANITIZER) || defined(ADDRESS_SANITIZER)
+#if DCHECK_IS_ON() || defined(LEAK_SANITIZER) || defined(ADDRESS_SANITIZER)
   // Allow the following addToFreeList() to add the newly allocated memory
   // to the free list.
   ASAN_UNPOISON_MEMORY_REGION(page->payload(), page->payloadSize());
@@ -900,7 +900,7 @@
 }
 
 void NormalPageArena::setAllocationPoint(Address point, size_t size) {
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
   if (point) {
     ASSERT(size);
     BasePage* page = pageFromObject(point);
@@ -1035,7 +1035,7 @@
   Address largeObjectAddress = pageMemory->writableStart();
   Address headerAddress =
       largeObjectAddress + LargeObjectPage::pageHeaderSize();
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
   // Verify that the allocated PageMemory is expectedly zeroed.
   for (size_t i = 0; i < largeObjectSize; ++i)
     ASSERT(!largeObjectAddress[i]);
@@ -1148,7 +1148,7 @@
   }
   entry = new (NotNull, address) FreeListEntry(size);
 
-#if ENABLE(ASSERT) || defined(LEAK_SANITIZER) || defined(ADDRESS_SANITIZER)
+#if DCHECK_IS_ON() || defined(LEAK_SANITIZER) || defined(ADDRESS_SANITIZER)
   // The following logic delays reusing free lists for (at least) one GC
   // cycle or coalescing. This is helpful to detect use-after-free errors
   // that could be caused by lazy sweeping etc.
@@ -1198,7 +1198,7 @@
     m_biggestFreeListIndex = index;
 }
 
-#if ENABLE(ASSERT) || defined(LEAK_SANITIZER) || defined(ADDRESS_SANITIZER) || \
+#if DCHECK_IS_ON() || defined(LEAK_SANITIZER) || defined(ADDRESS_SANITIZER) || \
     defined(MEMORY_SANITIZER)
 NO_SANITIZE_ADDRESS
 NO_SANITIZE_MEMORY
@@ -1339,7 +1339,7 @@
   arenaForNormalPage()->freePage(this);
 }
 
-#if !ENABLE(ASSERT) && !defined(LEAK_SANITIZER) && !defined(ADDRESS_SANITIZER)
+#if !DCHECK_IS_ON() && !defined(LEAK_SANITIZER) && !defined(ADDRESS_SANITIZER)
 static void discardPages(Address begin, Address end) {
   uintptr_t beginAddress =
       WTF::RoundUpToSystemPage(reinterpret_cast<uintptr_t>(begin));
@@ -1395,7 +1395,7 @@
     }
     if (startOfGap != headerAddress) {
       pageArena->addToFreeList(startOfGap, headerAddress - startOfGap);
-#if !ENABLE(ASSERT) && !defined(LEAK_SANITIZER) && !defined(ADDRESS_SANITIZER)
+#if !DCHECK_IS_ON() && !defined(LEAK_SANITIZER) && !defined(ADDRESS_SANITIZER)
       // Discarding pages increases page faults and may regress performance.
       // So we enable this only on low-RAM devices.
       if (MemoryCoordinator::isLowEndDevice())
@@ -1409,7 +1409,7 @@
   }
   if (startOfGap != payloadEnd()) {
     pageArena->addToFreeList(startOfGap, payloadEnd() - startOfGap);
-#if !ENABLE(ASSERT) && !defined(LEAK_SANITIZER) && !defined(ADDRESS_SANITIZER)
+#if !DCHECK_IS_ON() && !defined(LEAK_SANITIZER) && !defined(ADDRESS_SANITIZER)
     if (MemoryCoordinator::isLowEndDevice())
       discardPages(startOfGap + sizeof(FreeListEntry), payloadEnd());
 #endif
@@ -1459,7 +1459,7 @@
 // As compaction is under way, leave the freed memory accessible
 // while compacting the rest of the page. We just zap the payload
 // to catch out other finalizers trying to access it.
-#if ENABLE(ASSERT) || defined(LEAK_SANITIZER) || defined(ADDRESS_SANITIZER) || \
+#if DCHECK_IS_ON() || defined(LEAK_SANITIZER) || defined(ADDRESS_SANITIZER) || \
     defined(MEMORY_SANITIZER)
       FreeList::zapFreedMemory(payload, payloadSize);
 #endif
@@ -1514,7 +1514,7 @@
   if (markedObjectSize)
     pageArena->getThreadState()->increaseMarkedObjectSize(markedObjectSize);
 
-#if ENABLE(ASSERT) || defined(LEAK_SANITIZER) || defined(ADDRESS_SANITIZER) || \
+#if DCHECK_IS_ON() || defined(LEAK_SANITIZER) || defined(ADDRESS_SANITIZER) || \
     defined(MEMORY_SANITIZER)
   // Zap the unused portion, until it is either compacted into or freed.
   if (currentPage != this) {
@@ -1665,7 +1665,7 @@
   return header;
 }
 
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
 static bool isUninitializedMemory(void* objectPointer, size_t objectSize) {
   // Scan through the object's fields and check that they are all zero.
   Address* objectFields = reinterpret_cast<Address*>(objectPointer);
@@ -1763,7 +1763,7 @@
   heapInfo.freeCount += freeCount;
 }
 
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
 bool NormalPage::contains(Address addr) {
   Address blinkPageStart = roundToBlinkPageStart(getAddress());
   // Page is at aligned address plus guard page size.
@@ -1870,7 +1870,7 @@
   pageDump->AddScalar("dead_size", "bytes", deadSize);
 }
 
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
 bool LargeObjectPage::contains(Address object) {
   return roundToBlinkPageStart(getAddress()) <= object &&
          object < roundToBlinkPageEnd(getAddress() + size());

diff --git a/third_party/WebKit/Source/platform/heap/HeapPage.h b/third_party/WebKit/Source/platform/heap/HeapPage.h
index 8fbc94a..c401c9ef 100644
--- a/third_party/WebKit/Source/platform/heap/HeapPage.h
+++ b/third_party/WebKit/Source/platform/heap/HeapPage.h

@@ -103,7 +103,7 @@
   ASAN_UNPOISON_MEMORY_REGION(address, size);        \
   FreeList::checkFreedMemoryIsZapped(address, size); \
   ASAN_POISON_MEMORY_REGION(address, size)
-#elif ENABLE(ASSERT) || defined(LEAK_SANITIZER) || defined(ADDRESS_SANITIZER)
+#elif DCHECK_IS_ON() || defined(LEAK_SANITIZER) || defined(ADDRESS_SANITIZER)
 #define SET_MEMORY_INACCESSIBLE(address, size) \
   FreeList::zapFreedMemory(address, size);     \
   ASAN_POISON_MEMORY_REGION(address, size)
@@ -124,7 +124,7 @@
   } while (false)
 #endif
 
-#if !ENABLE(ASSERT) && CPU(64BIT)
+#if !DCHECK_IS_ON() && CPU(64BIT)
 #define USE_4BYTE_HEADER_PADDING 1
 #else
 #define USE_4BYTE_HEADER_PADDING 0
@@ -183,7 +183,7 @@
   // If gcInfoIndex is 0, this header is interpreted as a free list header.
   NO_SANITIZE_ADDRESS
   HeapObjectHeader(size_t size, size_t gcInfoIndex) {
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
     m_magic = magic;
 #endif
     // sizeof(HeapObjectHeader) must be equal to or smaller than
@@ -239,7 +239,7 @@
   size_t payloadSize();
   Address payloadEnd();
 
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
   bool checkHeader() const;
   // Zap magic number with a new magic number that means there was once an
   // object allocated here, but it was freed because nobody marked it during
@@ -255,7 +255,7 @@
 
  private:
   uint32_t m_encoded;
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
   uint16_t m_magic;
 #endif
 
@@ -284,7 +284,7 @@
   NO_SANITIZE_ADDRESS
   explicit FreeListEntry(size_t size)
       : HeapObjectHeader(size, gcInfoIndexForFreeListHeader), m_next(nullptr) {
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
     ASSERT(size >= sizeof(HeapObjectHeader));
     zapMagic();
 #endif
@@ -346,7 +346,7 @@
   return !!(*reinterpret_cast<Address*>(objectPointer));
 }
 
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
 // Sanity check for a page header address: the address of the page
 // header should be OS page size away from being Blink page size
 // aligned.
@@ -421,7 +421,7 @@
   virtual void takeSnapshot(base::trace_event::MemoryAllocatorDump*,
                             ThreadState::GCSnapshotInfo&,
                             HeapSnapshotInfo&) = 0;
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
   virtual bool contains(Address) = 0;
 #endif
   virtual size_t size() = 0;
@@ -494,7 +494,7 @@
   void takeSnapshot(base::trace_event::MemoryAllocatorDump*,
                     ThreadState::GCSnapshotInfo&,
                     HeapSnapshotInfo&) override;
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
   // Returns true for the whole blinkPageSize page that the page is on, even
   // for the header, and the unmapped guard page at the start. That ensures
   // the result can be used to populate the negative page cache.
@@ -572,7 +572,7 @@
   void takeSnapshot(base::trace_event::MemoryAllocatorDump*,
                     ThreadState::GCSnapshotInfo&,
                     HeapSnapshotInfo&) override;
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
   // Returns true for any address that is on one of the pages that this
   // large object uses. That ensures that we can use a negative result to
   // populate the negative page cache.
@@ -673,7 +673,7 @@
   // Returns true if the freelist snapshot is captured.
   bool takeSnapshot(const String& dumpBaseName);
 
-#if ENABLE(ASSERT) || defined(LEAK_SANITIZER) || defined(ADDRESS_SANITIZER) || \
+#if DCHECK_IS_ON() || defined(LEAK_SANITIZER) || defined(ADDRESS_SANITIZER) || \
     defined(MEMORY_SANITIZER)
   static void zapFreedMemory(Address, size_t);
   static void checkFreedMemoryIsZapped(Address, size_t);
@@ -707,14 +707,14 @@
   void cleanupPages();
 
   void takeSnapshot(const String& dumpBaseName, ThreadState::GCSnapshotInfo&);
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
   BasePage* findPageFromAddress(Address);
 #endif
   virtual void takeFreelistSnapshot(const String& dumpBaseName) {}
   virtual void clearFreeLists() {}
   void makeConsistentForGC();
   void makeConsistentForMutator();
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
   virtual bool isConsistentForGC() = 0;
 #endif
   size_t objectPayloadSizeForTesting();
@@ -760,7 +760,7 @@
     m_freeList.addToFreeList(address, size);
   }
   void clearFreeLists() override;
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
   bool isConsistentForGC() override;
   bool pagesToBeSweptContains(Address);
 #endif
@@ -822,7 +822,7 @@
   LargeObjectArena(ThreadState*, int);
   Address allocateLargeObjectPage(size_t, size_t gcInfoIndex);
   void freeLargeObjectPage(LargeObjectPage*);
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
   bool isConsistentForGC() override { return true; }
 #endif
  private:
@@ -852,7 +852,7 @@
   return result;
 }
 
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
 NO_SANITIZE_ADDRESS inline bool HeapObjectHeader::checkHeader() const {
   return !pageFromObject(this)->orphaned() && m_magic == magic;
 }

diff --git a/third_party/WebKit/Source/platform/heap/HeapTest.cpp b/third_party/WebKit/Source/platform/heap/HeapTest.cpp
index a9c6d49..ffef74e5 100644
--- a/third_party/WebKit/Source/platform/heap/HeapTest.cpp
+++ b/third_party/WebKit/Source/platform/heap/HeapTest.cpp

@@ -337,7 +337,7 @@
   void registerWeakTable(const void*,
                          EphemeronCallback,
                          EphemeronCallback) override {}
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
   bool weakTableRegistered(const void*) override { return false; }
 #endif
   void registerWeakCellWithCallback(void**, WeakCallback) override {}
@@ -1832,7 +1832,7 @@
   EXPECT_EQ(1, SimpleFinalizedObject::s_destructorCalls);
 }
 
-#if ENABLE(ASSERT) || defined(LEAK_SANITIZER) || defined(ADDRESS_SANITIZER)
+#if DCHECK_IS_ON() || defined(LEAK_SANITIZER) || defined(ADDRESS_SANITIZER)
 TEST(HeapTest, FreelistReuse) {
   clearOutOldGarbage();
 
@@ -5906,7 +5906,7 @@
 // The allocation & GC overhead is considerable for this test,
 // straining debug builds and lower-end targets too much to be
 // worth running.
-#if !ENABLE(ASSERT) && !OS(ANDROID)
+#if !DCHECK_IS_ON() && !OS(ANDROID)
   DeepEagerly* obj = nullptr;
   for (int i = 0; i < 10000000; i++)
     obj = new DeepEagerly(obj);

diff --git a/third_party/WebKit/Source/platform/heap/InlinedGlobalMarkingVisitor.h b/third_party/WebKit/Source/platform/heap/InlinedGlobalMarkingVisitor.h
index 5c88bc1a..ec8d5dbc 100644
--- a/third_party/WebKit/Source/platform/heap/InlinedGlobalMarkingVisitor.h
+++ b/third_party/WebKit/Source/platform/heap/InlinedGlobalMarkingVisitor.h

@@ -33,7 +33,7 @@
   using Impl::registerDelayedMarkNoTracing;
   using Impl::registerWeakTable;
   using Impl::registerWeakMembers;
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
   using Impl::weakTableRegistered;
 #endif
 

diff --git a/third_party/WebKit/Source/platform/heap/MarkingVisitor.h b/third_party/WebKit/Source/platform/heap/MarkingVisitor.h
index 63ca64d..926f4e0 100644
--- a/third_party/WebKit/Source/platform/heap/MarkingVisitor.h
+++ b/third_party/WebKit/Source/platform/heap/MarkingVisitor.h

@@ -41,7 +41,7 @@
     Impl::registerWeakTable(closure, iterationCallback, iterationDoneCallback);
   }
 
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
   virtual bool weakTableRegistered(const void* closure) {
     return Impl::weakTableRegistered(closure);
   }

diff --git a/third_party/WebKit/Source/platform/heap/MarkingVisitorImpl.h b/third_party/WebKit/Source/platform/heap/MarkingVisitorImpl.h
index 4b2f565..bd58304 100644
--- a/third_party/WebKit/Source/platform/heap/MarkingVisitorImpl.h
+++ b/third_party/WebKit/Source/platform/heap/MarkingVisitorImpl.h

@@ -80,7 +80,7 @@
         const_cast<void*>(closure), iterationCallback, iterationDoneCallback);
   }
 
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
   inline bool weakTableRegistered(const void* closure) {
     return toDerived()->heap().weakTableRegistered(closure);
   }
@@ -110,7 +110,7 @@
     HeapObjectHeader* header = HeapObjectHeader::fromPayload(objectPointer);
     if (header->isMarked())
       return false;
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
     toDerived()->markNoTracing(objectPointer);
 #else
     // Inline what the above markNoTracing() call expands to,

diff --git a/third_party/WebKit/Source/platform/heap/PagePool.cpp b/third_party/WebKit/Source/platform/heap/PagePool.cpp
index 97845c0..20e10ff0 100644
--- a/third_party/WebKit/Source/platform/heap/PagePool.cpp
+++ b/third_party/WebKit/Source/platform/heap/PagePool.cpp

@@ -126,7 +126,7 @@
   asanDisabledMemset(memory->writableStart(), 0, blinkPagePayloadSize());
 }
 
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
 bool OrphanedPagePool::contains(void* object) {
   for (int index = 0; index < BlinkGC::NumberOfArenas; ++index) {
     for (PoolEntry* entry = m_pool[index]; entry; entry = entry->next) {

diff --git a/third_party/WebKit/Source/platform/heap/PagePool.h b/third_party/WebKit/Source/platform/heap/PagePool.h
index 8a0e637..0d6515ce 100644
--- a/third_party/WebKit/Source/platform/heap/PagePool.h
+++ b/third_party/WebKit/Source/platform/heap/PagePool.h

@@ -64,7 +64,7 @@
   ~OrphanedPagePool();
   void addOrphanedPage(int, BasePage*);
   void decommitOrphanedPages();
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
   bool contains(void*);
 #endif
 

diff --git a/third_party/WebKit/Source/platform/heap/Persistent.h b/third_party/WebKit/Source/platform/heap/Persistent.h
index 794753c9..3fe022c 100644
--- a/third_party/WebKit/Source/platform/heap/Persistent.h
+++ b/third_party/WebKit/Source/platform/heap/Persistent.h

@@ -225,7 +225,7 @@
     ASSERT(state->checkThread());
     m_persistentNode = state->getPersistentRegion()->allocatePersistentNode(
         this, traceCallback);
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
     m_state = state;
 #endif
   }
@@ -314,10 +314,8 @@
   // m_raw is accessed most, so put it at the first field.
   T* m_raw;
   PersistentNode* m_persistentNode = nullptr;
-#if ENABLE(ASSERT)
-  ThreadState* m_state = nullptr;
-#endif
 #if DCHECK_IS_ON()
+  ThreadState* m_state = nullptr;
   const ThreadState* m_creationThreadState;
 #endif
 };
@@ -617,7 +615,7 @@
         TraceMethodDelegate<PersistentHeapCollectionBase<Collection>,
                             &PersistentHeapCollectionBase<
                                 Collection>::tracePersistent>::trampoline);
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
     m_state = state;
 #endif
   }
@@ -634,7 +632,7 @@
   }
 
   PersistentNode* m_persistentNode;
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
   ThreadState* m_state;
 #endif
 };

diff --git a/third_party/WebKit/Source/platform/heap/PersistentNode.h b/third_party/WebKit/Source/platform/heap/PersistentNode.h
index 6fbc02a..ee72628 100644
--- a/third_party/WebKit/Source/platform/heap/PersistentNode.h
+++ b/third_party/WebKit/Source/platform/heap/PersistentNode.h

@@ -23,7 +23,7 @@
  public:
   PersistentNode() : m_self(nullptr), m_trace(nullptr) { ASSERT(isUnused()); }
 
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
   ~PersistentNode() {
     // If you hit this assert, it means that the thread finished
     // without clearing persistent handles that the thread created.
@@ -214,7 +214,7 @@
 
   void tracePersistentNodes(Visitor* visitor) {
 // If this assert triggers, you're tracing without being in a LockScope.
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
     DCHECK(m_mutex.locked());
 #endif
     m_persistentRegion->tracePersistentNodes(

diff --git a/third_party/WebKit/Source/platform/heap/ThreadState.cpp b/third_party/WebKit/Source/platform/heap/ThreadState.cpp
index 00a5d0ef..d9cf18fc 100644
--- a/third_party/WebKit/Source/platform/heap/ThreadState.cpp
+++ b/third_party/WebKit/Source/platform/heap/ThreadState.cpp

@@ -1242,7 +1242,7 @@
     m_arenas[i]->prepareHeapForTermination();
 }
 
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
 BasePage* ThreadState::findPageFromAddress(Address address) {
   for (int i = 0; i < BlinkGC::NumberOfArenas; ++i) {
     if (BasePage* page = m_arenas[i]->findPageFromAddress(address))

diff --git a/third_party/WebKit/Source/platform/heap/ThreadState.h b/third_party/WebKit/Source/platform/heap/ThreadState.h
index 622d0c2..8769d2b 100644
--- a/third_party/WebKit/Source/platform/heap/ThreadState.h
+++ b/third_party/WebKit/Source/platform/heap/ThreadState.h

@@ -191,7 +191,7 @@
   static ThreadState* fromObject(const void*);
 
   bool isMainThread() const { return this == mainThreadState(); }
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
   bool checkThread() const { return m_thread == currentThread(); }
 #endif
 
@@ -354,7 +354,7 @@
     return m_arenas[arenaIndex];
   }
 
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
   // Infrastructure to determine if an address is within one of the
   // address ranges for the Blink heap. If the address is in the Blink
   // heap the containing heap page is returned.
@@ -528,7 +528,7 @@
       static_assert(sizeof(&T::invokePreFinalizer) > 0,
                     "USING_PRE_FINALIZER(T) must be defined.");
       ThreadState* state = ThreadState::current();
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
       DCHECK(state->checkThread());
 #endif
       DCHECK(!state->sweepForbidden());

diff --git a/third_party/WebKit/Source/platform/heap/TraceTraits.h b/third_party/WebKit/Source/platform/heap/TraceTraits.h
index 49f5b51..11d4d8c 100644
--- a/third_party/WebKit/Source/platform/heap/TraceTraits.h
+++ b/third_party/WebKit/Source/platform/heap/TraceTraits.h

@@ -49,7 +49,7 @@
  public:
   template <typename VisitorDispatcher>
   static void mark(VisitorDispatcher visitor, const T* t) {
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
     assertObjectHasGCInfo(const_cast<T*>(t), GCInfoTrait<T>::index());
 #endif
     // Default mark method of the trait just calls the two-argument mark

diff --git a/third_party/WebKit/Source/platform/heap/Visitor.cpp b/third_party/WebKit/Source/platform/heap/Visitor.cpp
index ed32a71e..9187501d 100644
--- a/third_party/WebKit/Source/platform/heap/Visitor.cpp
+++ b/third_party/WebKit/Source/platform/heap/Visitor.cpp

@@ -22,7 +22,7 @@
   // See ThreadState::runScheduledGC() why we need to already be in a
   // GCForbiddenScope before any safe point is entered.
   DCHECK(state->isGCForbidden());
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
   DCHECK(state->checkThread());
 #endif
 }

diff --git a/third_party/WebKit/Source/platform/heap/Visitor.h b/third_party/WebKit/Source/platform/heap/Visitor.h
index 7006d97..3e4b441 100644
--- a/third_party/WebKit/Source/platform/heap/Visitor.h
+++ b/third_party/WebKit/Source/platform/heap/Visitor.h

@@ -379,7 +379,7 @@
   virtual void registerWeakTable(const void*,
                                  EphemeronCallback,
                                  EphemeronCallback) = 0;
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
   virtual bool weakTableRegistered(const void*) = 0;
 #endif
 

diff --git a/third_party/WebKit/Source/platform/scheduler/base/task_queue_impl.cc b/third_party/WebKit/Source/platform/scheduler/base/task_queue_impl.cc
index 949a51a..c402dd0 100644
--- a/third_party/WebKit/Source/platform/scheduler/base/task_queue_impl.cc
+++ b/third_party/WebKit/Source/platform/scheduler/base/task_queue_impl.cc

@@ -154,8 +154,11 @@
     TimeDomain* time_domain)
     : task_queue_manager(task_queue_manager),
       time_domain(time_domain),
-      delayed_work_queue(new WorkQueue(task_queue, "delayed")),
-      immediate_work_queue(new WorkQueue(task_queue, "immediate")),
+      delayed_work_queue(
+          new WorkQueue(task_queue, "delayed", WorkQueue::QueueType::DELAYED)),
+      immediate_work_queue(new WorkQueue(task_queue,
+                                         "immediate",
+                                         WorkQueue::QueueType::IMMEDIATE)),
       set_index(0),
       is_enabled_refcount(0),
       voter_refcount(0),
@@ -325,7 +328,7 @@
     EnqueueOrder sequence_number,
     bool nestable) {
   if (any_thread().immediate_incoming_queue.empty())
-    any_thread().time_domain->RegisterAsUpdatableTaskQueue(this);
+    any_thread().time_domain->OnQueueHasIncomingImmediateWork(this);
   // If the |immediate_incoming_queue| is empty we need a DoWork posted to make
   // it run.
   if (any_thread().immediate_incoming_queue.empty()) {
@@ -346,6 +349,20 @@
   TraceQueueSize(true);
 }
 
+void TaskQueueImpl::ReloadImmediateWorkQueueIfEmpty() {
+  if (!main_thread_only().immediate_work_queue->Empty())
+    return;
+
+  main_thread_only().immediate_work_queue->ReloadEmptyImmediateQueue();
+}
+
+WTF::Deque<TaskQueueImpl::Task> TaskQueueImpl::TakeImmediateIncomingQueue() {
+  base::AutoLock lock(any_thread_lock_);
+  WTF::Deque<TaskQueueImpl::Task> queue;
+  queue.swap(any_thread().immediate_incoming_queue);
+  return queue;
+}
+
 bool TaskQueueImpl::IsEmpty() const {
   if (!main_thread_only().delayed_work_queue->Empty() ||
       !main_thread_only().delayed_incoming_queue.empty() ||
@@ -421,20 +438,6 @@
   }
 }
 
-bool TaskQueueImpl::MaybeUpdateImmediateWorkQueues() {
-  if (!main_thread_only().task_queue_manager)
-    return false;
-
-  if (!main_thread_only().immediate_work_queue->Empty())
-    return true;
-
-  base::AutoLock lock(any_thread_lock_);
-  main_thread_only().immediate_work_queue->SwapLocked(
-      any_thread().immediate_incoming_queue);
-  // |immediate_work_queue| is now empty so updates are no longer required.
-  return false;
-}
-
 void TaskQueueImpl::TraceQueueSize(bool is_locked) const {
   bool is_tracing;
   TRACE_EVENT_CATEGORY_GROUP_ENABLED(disabled_by_default_tracing_category_,
@@ -576,7 +579,7 @@
     any_thread().time_domain = time_domain;
   }
   // We rely here on TimeDomain::MigrateQueue being thread-safe to use with
-  // TimeDomain::Register/UnregisterAsUpdatableTaskQueue.
+  // TimeDomain::Register.
   main_thread_only().time_domain->MigrateQueue(this, time_domain);
   main_thread_only().time_domain = time_domain;
 }
@@ -798,8 +801,8 @@
     return;
 
   if (enable) {
-    // Note it's the job of the selector to tell the TaskQueueManager if
-    // a DoWork needs posting.
+    // Note the selector calls TaskQueueManager::OnTaskQueueEnabled which posts
+    // a DoWork if needed.
     main_thread_only().task_queue_manager->selector_.EnableQueue(this);
   } else {
     main_thread_only().task_queue_manager->selector_.DisableQueue(this);
@@ -835,6 +838,12 @@
   main_thread_only().delayed_incoming_queue = std::move(remaining_tasks);
 }
 
+void TaskQueueImpl::PushImmediateIncomingTaskForTest(
+    TaskQueueImpl::Task&& task) {
+  base::AutoLock lock(any_thread_lock_);
+  any_thread().immediate_incoming_queue.push_back(std::move(task));
+}
+
 }  // namespace internal
 }  // namespace scheduler
 }  // namespace blink

diff --git a/third_party/WebKit/Source/platform/scheduler/base/task_queue_impl.h b/third_party/WebKit/Source/platform/scheduler/base/task_queue_impl.h
index 6f85115..8c31e12 100644
--- a/third_party/WebKit/Source/platform/scheduler/base/task_queue_impl.h
+++ b/third_party/WebKit/Source/platform/scheduler/base/task_queue_impl.h

@@ -140,9 +140,8 @@
   const char* GetName() const override;
   QueueType GetQueueType() const override;
 
-  // If this returns false then future updates for this queue are not needed
-  // unless requested.
-  bool MaybeUpdateImmediateWorkQueues();
+  // Must only be called from the thread this task queue was created on.
+  void ReloadImmediateWorkQueueIfEmpty();
 
   void AsValueInto(base::trace_event::TracedValue* state) const;
 
@@ -193,6 +192,7 @@
     main_thread_only().heap_handle = heap_handle;
   }
 
+  void PushImmediateIncomingTaskForTest(TaskQueueImpl::Task&& task);
   EnqueueOrder GetFenceForTest() const;
 
   class QueueEnabledVoterImpl : public QueueEnabledVoter {
@@ -294,6 +294,10 @@
       EnqueueOrder sequence_number,
       bool nestable);
 
+  // Extracts all the tasks from the immediate incoming queue and clears it.
+  // Can be called from any thread.
+  WTF::Deque<TaskQueueImpl::Task> TakeImmediateIncomingQueue();
+
   // As BlockedByFence but safe to be called while locked.
   bool BlockedByFenceLocked() const;
 
@@ -323,9 +327,9 @@
   }
 
   const QueueType type_;
-  const char* name_;
-  const char* disabled_by_default_tracing_category_;
-  const char* disabled_by_default_verbose_tracing_category_;
+  const char* const name_;
+  const char* const disabled_by_default_tracing_category_;
+  const char* const disabled_by_default_verbose_tracing_category_;
 
   base::ThreadChecker main_thread_checker_;
   MainThreadOnly main_thread_only_;

diff --git a/third_party/WebKit/Source/platform/scheduler/base/time_domain.cc b/third_party/WebKit/Source/platform/scheduler/base/time_domain.cc
index 59e3e34..25d0caf 100644
--- a/third_party/WebKit/Source/platform/scheduler/base/time_domain.cc
+++ b/third_party/WebKit/Source/platform/scheduler/base/time_domain.cc

@@ -27,7 +27,11 @@
 void TimeDomain::UnregisterQueue(internal::TaskQueueImpl* queue) {
   DCHECK(main_thread_checker_.CalledOnValidThread());
   DCHECK_EQ(queue->GetTimeDomain(), this);
-  UnregisterAsUpdatableTaskQueue(queue);
+
+  {
+    base::AutoLock lock(has_incoming_immediate_work_lock_);
+    has_incoming_immediate_work_.erase(queue);
+  }
 
   // If no wakeup has been requested then bail out.
   if (!queue->heap_handle().IsValid())
@@ -47,8 +51,16 @@
 
   // Make sure we remember to update |queue| if it's got incoming immediate
   // work.
-  if (UnregisterAsUpdatableTaskQueue(queue))
-    destination_time_domain->updatable_queue_set_.insert(queue);
+  bool has_incoming_immediate_work;
+  {
+    base::AutoLock lock(has_incoming_immediate_work_lock_);
+    has_incoming_immediate_work = has_incoming_immediate_work_.erase(queue);
+  }
+  if (has_incoming_immediate_work) {
+    base::AutoLock lock(
+        destination_time_domain->has_incoming_immediate_work_lock_);
+    destination_time_domain->has_incoming_immediate_work_.insert(queue);
+  }
 
   // If no wakeup has been requested then bail out.
   if (!queue->heap_handle().IsValid())
@@ -94,64 +106,32 @@
     observer_->OnTimeDomainHasDelayedWork(queue);
 }
 
-void TimeDomain::RegisterAsUpdatableTaskQueue(internal::TaskQueueImpl* queue) {
+void TimeDomain::OnQueueHasIncomingImmediateWork(
+    internal::TaskQueueImpl* queue) {
   {
-    base::AutoLock lock(newly_updatable_lock_);
-    newly_updatable_.push_back(queue);
+    base::AutoLock lock(has_incoming_immediate_work_lock_);
+    has_incoming_immediate_work_.insert(queue);
   }
+
   if (observer_)
     observer_->OnTimeDomainHasImmediateWork(queue);
 }
 
-bool TimeDomain::UnregisterAsUpdatableTaskQueue(
-    internal::TaskQueueImpl* queue) {
-  DCHECK(main_thread_checker_.CalledOnValidThread());
-
-  bool was_updatable = updatable_queue_set_.erase(queue) != 0;
-
-  base::AutoLock lock(newly_updatable_lock_);
-  // Remove all copies of |queue| from |newly_updatable_|.
-  for (size_t i = 0; i < newly_updatable_.size();) {
-    if (newly_updatable_[i] == queue) {
-      // Move last element into slot #i and then compact.
-      newly_updatable_[i] = newly_updatable_.back();
-      newly_updatable_.pop_back();
-      was_updatable = true;
-    } else {
-      i++;
-    }
-  }
-  return was_updatable;
-}
-
 void TimeDomain::UpdateWorkQueues(LazyNow lazy_now) {
   DCHECK(main_thread_checker_.CalledOnValidThread());
 
   // Move any ready delayed tasks into the Incoming queues.
   WakeupReadyDelayedQueues(&lazy_now);
 
-  MoveNewlyUpdatableQueuesIntoUpdatableQueueSet();
+  std::set<internal::TaskQueueImpl*> queues_to_reload_if_empty;
 
-  std::set<internal::TaskQueueImpl*>::iterator iter =
-      updatable_queue_set_.begin();
-  while (iter != updatable_queue_set_.end()) {
-    std::set<internal::TaskQueueImpl*>::iterator queue_it = iter++;
-    internal::TaskQueueImpl* queue = *queue_it;
-
-    // Update the queue and remove from the set if subsequent updates are not
-    // required.
-    if (!queue->MaybeUpdateImmediateWorkQueues())
-      updatable_queue_set_.erase(queue_it);
+  {
+    base::AutoLock lock(has_incoming_immediate_work_lock_);
+    std::swap(queues_to_reload_if_empty, has_incoming_immediate_work_);
   }
-}
 
-void TimeDomain::MoveNewlyUpdatableQueuesIntoUpdatableQueueSet() {
-  DCHECK(main_thread_checker_.CalledOnValidThread());
-  base::AutoLock lock(newly_updatable_lock_);
-  while (!newly_updatable_.empty()) {
-    updatable_queue_set_.insert(newly_updatable_.back());
-    newly_updatable_.pop_back();
-  }
+  for (internal::TaskQueueImpl* queue : queues_to_reload_if_empty)
+    queue->ReloadImmediateWorkQueueIfEmpty();
 }
 
 void TimeDomain::WakeupReadyDelayedQueues(LazyNow* lazy_now) {
@@ -190,10 +170,13 @@
 void TimeDomain::AsValueInto(base::trace_event::TracedValue* state) const {
   state->BeginDictionary();
   state->SetString("name", GetName());
-  state->BeginArray("updatable_queue_set");
-  for (auto* queue : updatable_queue_set_)
-    state->AppendString(queue->GetName());
-  state->EndArray();
+  {
+    base::AutoLock lock(has_incoming_immediate_work_lock_);
+    state->BeginArray("has_incoming_immediate_work");
+    for (internal::TaskQueueImpl* queue : has_incoming_immediate_work_)
+      state->AppendString(queue->GetName());
+    state->EndArray();
+  }
   state->SetInteger("registered_delay_count", delayed_wakeup_queue_.size());
   if (!delayed_wakeup_queue_.empty()) {
     base::TimeDelta delay = delayed_wakeup_queue_.min().time - Now();

diff --git a/third_party/WebKit/Source/platform/scheduler/base/time_domain.h b/third_party/WebKit/Source/platform/scheduler/base/time_domain.h
index 639d174..f7f31b0 100644
--- a/third_party/WebKit/Source/platform/scheduler/base/time_domain.h
+++ b/third_party/WebKit/Source/platform/scheduler/base/time_domain.h

@@ -88,9 +88,11 @@
   // the next task was posted to and it returns true.  Returns false otherwise.
   bool NextScheduledTaskQueue(TaskQueue** out_task_queue) const;
 
-  // Adds |queue| to the set of task queues that UpdateWorkQueues calls
-  // UpdateWorkQueue on.
-  void RegisterAsUpdatableTaskQueue(internal::TaskQueueImpl* queue);
+  // Adds |queue| to |has_incoming_immediate_work_| which causes
+  // UpdateWorkQueues to reload the immediate work queue if empty. Can be
+  // called from any thread.
+  // TODO(alexclarke): Move this to the TaskQueueManager.
+  void OnQueueHasIncomingImmediateWork(internal::TaskQueueImpl* queue);
 
   // Schedules a call to TaskQueueImpl::WakeUpForDelayedWork when this
   // TimeDomain reaches |delayed_run_time|.  This supersedes any previously
@@ -102,10 +104,6 @@
   // Registers the |queue|.
   void RegisterQueue(internal::TaskQueueImpl* queue);
 
-  // Removes |queue| from the set of task queues that UpdateWorkQueues calls
-  // UpdateWorkQueue on. Returns true if |queue| was updatable.
-  bool UnregisterAsUpdatableTaskQueue(internal::TaskQueueImpl* queue);
-
   // Removes |queue| from all internal data structures.
   void UnregisterQueue(internal::TaskQueueImpl* queue);
 
@@ -136,8 +134,6 @@
   }
 
  private:
-  void MoveNewlyUpdatableQueuesIntoUpdatableQueueSet();
-
   struct DelayedWakeup {
     base::TimeTicks time;
     internal::TaskQueueImpl* queue;
@@ -164,14 +160,13 @@
 
   IntrusiveHeap<DelayedWakeup> delayed_wakeup_queue_;
 
-  // This lock guards only |newly_updatable_|.  It's not expected to be heavily
-  // contended.
-  base::Lock newly_updatable_lock_;
-  std::vector<internal::TaskQueueImpl*> newly_updatable_;
+  // This lock guards only |has_incoming_immediate_work_|.  It's not expected to
+  // be heavily contended.
+  mutable base::Lock has_incoming_immediate_work_lock_;
 
-  // Set of task queues with avaliable work on the incoming queue.  This should
-  // only be accessed from the main thread.
-  std::set<internal::TaskQueueImpl*> updatable_queue_set_;
+  // Set of task queues with newly available work on the incoming queue.
+  // TODO(alexclarke): Move this to the TaskQueueManager.
+  std::set<internal::TaskQueueImpl*> has_incoming_immediate_work_;
 
   Observer* observer_;  // NOT OWNED.
 

diff --git a/third_party/WebKit/Source/platform/scheduler/base/time_domain_unittest.cc b/third_party/WebKit/Source/platform/scheduler/base/time_domain_unittest.cc
index 69224757..7a5e35e 100644
--- a/third_party/WebKit/Source/platform/scheduler/base/time_domain_unittest.cc
+++ b/third_party/WebKit/Source/platform/scheduler/base/time_domain_unittest.cc

@@ -35,7 +35,7 @@
   using TimeDomain::ScheduleDelayedWork;
   using TimeDomain::UnregisterQueue;
   using TimeDomain::UpdateWorkQueues;
-  using TimeDomain::RegisterAsUpdatableTaskQueue;
+  using TimeDomain::OnQueueHasIncomingImmediateWork;
 
   // TimeSource implementation:
   LazyNow CreateLazyNow() const override { return LazyNow(now_); }
@@ -235,7 +235,7 @@
 
 TEST_F(TimeDomainWithObserverTest, OnTimeDomainHasImmediateWork) {
   EXPECT_CALL(*observer_, OnTimeDomainHasImmediateWork(task_queue_.get()));
-  time_domain_->RegisterAsUpdatableTaskQueue(task_queue_.get());
+  time_domain_->OnQueueHasIncomingImmediateWork(task_queue_.get());
 }
 
 TEST_F(TimeDomainWithObserverTest, OnTimeDomainHasDelayedWork) {

diff --git a/third_party/WebKit/Source/platform/scheduler/base/work_queue.cc b/third_party/WebKit/Source/platform/scheduler/base/work_queue.cc
index 0b7d0cd..64cf33a 100644
--- a/third_party/WebKit/Source/platform/scheduler/base/work_queue.cc
+++ b/third_party/WebKit/Source/platform/scheduler/base/work_queue.cc

@@ -10,12 +10,15 @@
 namespace scheduler {
 namespace internal {
 
-WorkQueue::WorkQueue(TaskQueueImpl* task_queue, const char* name)
+WorkQueue::WorkQueue(TaskQueueImpl* task_queue,
+                     const char* name,
+                     QueueType queue_type)
     : work_queue_sets_(nullptr),
       task_queue_(task_queue),
       work_queue_set_index_(0),
       name_(name),
-      fence_(0) {}
+      fence_(0),
+      queue_type_(queue_type) {}
 
 void WorkQueue::AsValueInto(base::trace_event::TracedValue* state) const {
   for (const TaskQueueImpl::Task& task : work_queue_) {
@@ -76,7 +79,7 @@
 
   // If we hit the fence, pretend to WorkQueueSets that we're empty.
   if (work_queue_sets_ && !BlockedByFence())
-    work_queue_sets_->OnPushQueue(this);
+    work_queue_sets_->OnTaskPushedToEmptyQueue(this);
 }
 
 void WorkQueue::PopTaskForTest() {
@@ -85,14 +88,16 @@
   work_queue_.pop_front();
 }
 
-void WorkQueue::SwapLocked(WTF::Deque<TaskQueueImpl::Task>& incoming_queue) {
+void WorkQueue::ReloadEmptyImmediateQueue() {
   DCHECK(work_queue_.empty());
-  work_queue_.swap(incoming_queue);
+
+  work_queue_ = task_queue_->TakeImmediateIncomingQueue();
   if (work_queue_.empty())
     return;
+
   // If we hit the fence, pretend to WorkQueueSets that we're empty.
   if (work_queue_sets_ && !BlockedByFence())
-    work_queue_sets_->OnPushQueue(this);
+    work_queue_sets_->OnTaskPushedToEmptyQueue(this);
 }
 
 TaskQueueImpl::Task WorkQueue::TakeTaskFromWorkQueue() {
@@ -106,6 +111,13 @@
   }
 
   TaskQueueImpl::Task pending_task = work_queue_.takeFirst();
+  // NB immediate tasks have a different pipeline to delayed ones.
+  if (queue_type_ == QueueType::IMMEDIATE && work_queue_.empty()) {
+    // Short-circuit the queue reload so that OnPopQueue does the right thing.
+    work_queue_ = task_queue_->TakeImmediateIncomingQueue();
+  }
+  // OnPopQueue calls GetFrontTaskEnqueueOrder which checks BlockedByFence() so
+  // we don't need to here.
   work_queue_sets_->OnPopQueue(this);
   task_queue_->TraceQueueSize(false);
   return pending_task;
@@ -127,7 +139,7 @@
   // Moving the fence forward may unblock some tasks.
   if (work_queue_sets_ && !work_queue_.empty() && was_blocked_by_fence &&
       !BlockedByFence()) {
-    work_queue_sets_->OnPushQueue(this);
+    work_queue_sets_->OnTaskPushedToEmptyQueue(this);
     return true;
   }
   // Fence insertion may have blocked all tasks in this work queue.
@@ -140,7 +152,7 @@
   bool was_blocked_by_fence = BlockedByFence();
   fence_ = 0;
   if (work_queue_sets_ && !work_queue_.empty() && was_blocked_by_fence) {
-    work_queue_sets_->OnPushQueue(this);
+    work_queue_sets_->OnTaskPushedToEmptyQueue(this);
     return true;
   }
   return false;

diff --git a/third_party/WebKit/Source/platform/scheduler/base/work_queue.h b/third_party/WebKit/Source/platform/scheduler/base/work_queue.h
index 53f1efce..5449800 100644
--- a/third_party/WebKit/Source/platform/scheduler/base/work_queue.h
+++ b/third_party/WebKit/Source/platform/scheduler/base/work_queue.h

@@ -31,7 +31,9 @@
 // throttling mechanisms.
 class BLINK_PLATFORM_EXPORT WorkQueue {
  public:
-  WorkQueue(TaskQueueImpl* task_queue, const char* name);
+  enum class QueueType { DELAYED, IMMEDIATE };
+
+  WorkQueue(TaskQueueImpl* task_queue, const char* name, QueueType queue_type);
   ~WorkQueue();
 
   // Associates this work queue with the given work queue sets. This must be
@@ -63,10 +65,10 @@
   // informs the WorkQueueSets if the head changed.
   void Push(TaskQueueImpl::Task task);
 
-  // Swap the |work_queue_| with |incoming_queue| and if a fence hasn't been
-  // reached it informs the WorkQueueSets if the head changed. Assumes
-  // |task_queue_->any_thread_lock_| is locked.
-  void SwapLocked(WTF::Deque<TaskQueueImpl::Task>& incoming_queue);
+  // Reloads the empty |work_queue_| with
+  // |task_queue_->TakeImmediateIncomingQueue| and if a fence hasn't been
+  // reached it informs the WorkQueueSets if the head changed.
+  void ReloadEmptyImmediateQueue();
 
   size_t Size() const { return work_queue_.size(); }
 
@@ -114,12 +116,13 @@
 
  private:
   WTF::Deque<TaskQueueImpl::Task> work_queue_;
-  WorkQueueSets* work_queue_sets_;  // NOT OWNED.
-  TaskQueueImpl* task_queue_;       // NOT OWNED.
+  WorkQueueSets* work_queue_sets_;   // NOT OWNED.
+  TaskQueueImpl* const task_queue_;  // NOT OWNED.
   size_t work_queue_set_index_;
   HeapHandle heap_handle_;
-  const char* name_;
+  const char* const name_;
   EnqueueOrder fence_;
+  const QueueType queue_type_;
 
   DISALLOW_COPY_AND_ASSIGN(WorkQueue);
 };

diff --git a/third_party/WebKit/Source/platform/scheduler/base/work_queue_sets.cc b/third_party/WebKit/Source/platform/scheduler/base/work_queue_sets.cc
index 1194df9..69d81a5 100644
--- a/third_party/WebKit/Source/platform/scheduler/base/work_queue_sets.cc
+++ b/third_party/WebKit/Source/platform/scheduler/base/work_queue_sets.cc

@@ -53,7 +53,7 @@
   work_queue_heaps_[set_index].insert({enqueue_order, work_queue});
 }
 
-void WorkQueueSets::OnPushQueue(WorkQueue* work_queue) {
+void WorkQueueSets::OnTaskPushedToEmptyQueue(WorkQueue* work_queue) {
   // NOTE if this function changes, we need to keep |WorkQueueSets::AddQueue| in
   // sync.
   DCHECK_EQ(this, work_queue->work_queue_sets());

diff --git a/third_party/WebKit/Source/platform/scheduler/base/work_queue_sets.h b/third_party/WebKit/Source/platform/scheduler/base/work_queue_sets.h
index 923c27e3..f2749c1 100644
--- a/third_party/WebKit/Source/platform/scheduler/base/work_queue_sets.h
+++ b/third_party/WebKit/Source/platform/scheduler/base/work_queue_sets.h

@@ -43,7 +43,7 @@
   void ChangeSetIndex(WorkQueue* queue, size_t set_index);
 
   // O(log num queues)
-  void OnPushQueue(WorkQueue* work_queue);
+  void OnTaskPushedToEmptyQueue(WorkQueue* work_queue);
 
   // If empty it's O(1) amortized, otherwise it's O(log num queues)
   // Assumes |work_queue| contains the lowest enqueue order in the set.

diff --git a/third_party/WebKit/Source/platform/scheduler/base/work_queue_sets_unittest.cc b/third_party/WebKit/Source/platform/scheduler/base/work_queue_sets_unittest.cc
index 0f29b01..de0b9c4 100644
--- a/third_party/WebKit/Source/platform/scheduler/base/work_queue_sets_unittest.cc
+++ b/third_party/WebKit/Source/platform/scheduler/base/work_queue_sets_unittest.cc

@@ -35,7 +35,8 @@
   };
 
   WorkQueue* NewTaskQueue(const char* queue_name) {
-    WorkQueue* queue = new WorkQueue(nullptr, "test");
+    WorkQueue* queue =
+        new WorkQueue(nullptr, "test", WorkQueue::QueueType::IMMEDIATE);
     work_queues_.push_back(base::WrapUnique(queue));
     work_queue_sets_->AddQueue(queue, TaskQueue::CONTROL_PRIORITY);
     return queue;
@@ -70,7 +71,7 @@
       work_queue_sets_->GetOldestQueueInSet(set, &selected_work_queue));
 }
 
-TEST_F(WorkQueueSetsTest, OnPushQueue) {
+TEST_F(WorkQueueSetsTest, OnTaskPushedToEmptyQueue) {
   WorkQueue* work_queue = NewTaskQueue("queue");
   size_t set = TaskQueue::NORMAL_PRIORITY;
   work_queue_sets_->ChangeSetIndex(work_queue, set);
@@ -79,7 +80,7 @@
   EXPECT_FALSE(
       work_queue_sets_->GetOldestQueueInSet(set, &selected_work_queue));
 
-  // Calls OnPushQueue.
+  // Calls OnTaskPushedToEmptyQueue.
   work_queue->Push(FakeTaskWithEnqueueOrder(10));
 
   EXPECT_TRUE(work_queue_sets_->GetOldestQueueInSet(set, &selected_work_queue));

diff --git a/third_party/WebKit/Source/platform/scheduler/base/work_queue_unittest.cc b/third_party/WebKit/Source/platform/scheduler/base/work_queue_unittest.cc
index 7b11f440..800e868 100644
--- a/third_party/WebKit/Source/platform/scheduler/base/work_queue_unittest.cc
+++ b/third_party/WebKit/Source/platform/scheduler/base/work_queue_unittest.cc

@@ -28,11 +28,10 @@
         new TaskQueueImpl(nullptr, time_domain_.get(),
                           TaskQueue::Spec(TaskQueue::QueueType::TEST), "", ""));
 
-    work_queue_.reset(new WorkQueue(task_queue_.get(), "test"));
+    work_queue_.reset(new WorkQueue(task_queue_.get(), "test",
+                                    WorkQueue::QueueType::IMMEDIATE));
     work_queue_sets_.reset(new WorkQueueSets(1, "test"));
     work_queue_sets_->AddQueue(work_queue_.get(), 0);
-
-    incoming_queue_.reset(new WTF::Deque<TaskQueueImpl::Task>());
   }
 
   void TearDown() override { work_queue_sets_->RemoveQueue(work_queue_.get()); }
@@ -123,19 +122,18 @@
   EXPECT_FALSE(work_queue_sets_->GetOldestQueueInSet(0, &work_queue));
 }
 
-TEST_F(WorkQueueTest, SwapLocked) {
-  incoming_queue_->push_back(FakeTaskWithEnqueueOrder(2));
-  incoming_queue_->push_back(FakeTaskWithEnqueueOrder(3));
-  incoming_queue_->push_back(FakeTaskWithEnqueueOrder(4));
+TEST_F(WorkQueueTest, ReloadEmptyImmediateQueue) {
+  task_queue_->PushImmediateIncomingTaskForTest(FakeTaskWithEnqueueOrder(2));
+  task_queue_->PushImmediateIncomingTaskForTest(FakeTaskWithEnqueueOrder(3));
+  task_queue_->PushImmediateIncomingTaskForTest(FakeTaskWithEnqueueOrder(4));
 
   WorkQueue* work_queue;
   EXPECT_FALSE(work_queue_sets_->GetOldestQueueInSet(0, &work_queue));
   EXPECT_TRUE(work_queue_->Empty());
-  work_queue_->SwapLocked(*incoming_queue_.get());
+  work_queue_->ReloadEmptyImmediateQueue();
 
   EXPECT_TRUE(work_queue_sets_->GetOldestQueueInSet(0, &work_queue));
   EXPECT_FALSE(work_queue_->Empty());
-  EXPECT_TRUE(incoming_queue_->empty());
 
   ASSERT_NE(nullptr, work_queue_->GetFrontTask());
   EXPECT_EQ(2ull, work_queue_->GetFrontTask()->enqueue_order());
@@ -144,20 +142,19 @@
   EXPECT_EQ(4ull, work_queue_->GetBackTask()->enqueue_order());
 }
 
-TEST_F(WorkQueueTest, SwapLockedAfterFenceHit) {
+TEST_F(WorkQueueTest, ReloadEmptyImmediateQueueAfterFenceHit) {
   work_queue_->InsertFence(1);
-  incoming_queue_->push_back(FakeTaskWithEnqueueOrder(2));
-  incoming_queue_->push_back(FakeTaskWithEnqueueOrder(3));
-  incoming_queue_->push_back(FakeTaskWithEnqueueOrder(4));
+  task_queue_->PushImmediateIncomingTaskForTest(FakeTaskWithEnqueueOrder(2));
+  task_queue_->PushImmediateIncomingTaskForTest(FakeTaskWithEnqueueOrder(3));
+  task_queue_->PushImmediateIncomingTaskForTest(FakeTaskWithEnqueueOrder(4));
 
   WorkQueue* work_queue;
   EXPECT_FALSE(work_queue_sets_->GetOldestQueueInSet(0, &work_queue));
   EXPECT_TRUE(work_queue_->Empty());
-  work_queue_->SwapLocked(*incoming_queue_.get());
+  work_queue_->ReloadEmptyImmediateQueue();
 
   EXPECT_FALSE(work_queue_sets_->GetOldestQueueInSet(0, &work_queue));
   EXPECT_FALSE(work_queue_->Empty());
-  EXPECT_TRUE(incoming_queue_->empty());
 
   ASSERT_NE(nullptr, work_queue_->GetFrontTask());
   EXPECT_EQ(2ull, work_queue_->GetFrontTask()->enqueue_order());

diff --git a/third_party/WebKit/Source/platform/text/BidiResolver.h b/third_party/WebKit/Source/platform/text/BidiResolver.h
index fafb6c288..3257d331 100644
--- a/third_party/WebKit/Source/platform/text/BidiResolver.h
+++ b/third_party/WebKit/Source/platform/text/BidiResolver.h

@@ -223,7 +223,7 @@
         m_nestedIsolateCount(0),
         m_trailingSpaceRun(0) {}
 
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
   ~BidiResolver();
 #endif
 
@@ -375,7 +375,7 @@
   HashMap<Run*, MidpointState<Iterator>> m_midpointStateForIsolatedRun;
 };
 
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
 template <class Iterator, class Run, class IsolatedRun>
 BidiResolver<Iterator, Run, IsolatedRun>::~BidiResolver() {
   // The owner of this resolver should have handled the isolated runs.

diff --git a/third_party/WebKit/Source/platform/weborigin/KURL.cpp b/third_party/WebKit/Source/platform/weborigin/KURL.cpp
index 7a1e7edc..c81f2d3a 100644
--- a/third_party/WebKit/Source/platform/weborigin/KURL.cpp
+++ b/third_party/WebKit/Source/platform/weborigin/KURL.cpp

@@ -48,7 +48,7 @@
 static const int invalidPortNumber = 0xFFFF;
 
 static void assertProtocolIsGood(const char* protocol) {
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
   DCHECK_NE(protocol, "");
   const char* p = protocol;
   while (*p) {

diff --git a/third_party/WebKit/Source/platform/weborigin/KURL.h b/third_party/WebKit/Source/platform/weborigin/KURL.h
index 91c7851..c6d38fb 100644
--- a/third_party/WebKit/Source/platform/weborigin/KURL.h
+++ b/third_party/WebKit/Source/platform/weborigin/KURL.h

@@ -191,6 +191,8 @@
 
   bool isSafeToSendToAnotherThread() const;
 
+  bool whitespaceRemoved() const { return m_parsed.whitespace_removed; }
+
  private:
   void init(const KURL& base,
             const String& relative,

diff --git a/third_party/WebKit/Source/platform/weborigin/KURLTest.cpp b/third_party/WebKit/Source/platform/weborigin/KURLTest.cpp
index 8746f2af..896f65e 100644
--- a/third_party/WebKit/Source/platform/weborigin/KURLTest.cpp
+++ b/third_party/WebKit/Source/platform/weborigin/KURLTest.cpp

@@ -302,6 +302,37 @@
   EXPECT_EQ(encodeWithURLEscapeSequences(precomposed), "%C4%99");
 }
 
+TEST(KURLTest, RemoveWhitespace) {
+  struct {
+    const char* input;
+    const char* expected;
+  } cases[] = {
+      {"ht\ntps://example.com/yay?boo#foo", "https://example.com/yay?boo#foo"},
+      {"ht\ttps://example.com/yay?boo#foo", "https://example.com/yay?boo#foo"},
+      {"ht\rtps://example.com/yay?boo#foo", "https://example.com/yay?boo#foo"},
+      {"https://exa\nmple.com/yay?boo#foo", "https://example.com/yay?boo#foo"},
+      {"https://exa\tmple.com/yay?boo#foo", "https://example.com/yay?boo#foo"},
+      {"https://exa\rmple.com/yay?boo#foo", "https://example.com/yay?boo#foo"},
+      {"https://example.com/y\nay?boo#foo", "https://example.com/yay?boo#foo"},
+      {"https://example.com/y\tay?boo#foo", "https://example.com/yay?boo#foo"},
+      {"https://example.com/y\ray?boo#foo", "https://example.com/yay?boo#foo"},
+      {"https://example.com/yay?b\noo#foo", "https://example.com/yay?boo#foo"},
+      {"https://example.com/yay?b\too#foo", "https://example.com/yay?boo#foo"},
+      {"https://example.com/yay?b\roo#foo", "https://example.com/yay?boo#foo"},
+      {"https://example.com/yay?boo#f\noo", "https://example.com/yay?boo#foo"},
+      {"https://example.com/yay?boo#f\too", "https://example.com/yay?boo#foo"},
+      {"https://example.com/yay?boo#f\roo", "https://example.com/yay?boo#foo"},
+  };
+
+  for (const auto& test : cases) {
+    const KURL input(ParsedURLString, test.input);
+    const KURL expected(ParsedURLString, test.expected);
+    EXPECT_EQ(input, expected);
+    EXPECT_TRUE(input.whitespaceRemoved());
+    EXPECT_FALSE(expected.whitespaceRemoved());
+  }
+}
+
 TEST(KURLTest, ResolveEmpty) {
   KURL emptyBase;
 

diff --git a/third_party/WebKit/Source/wtf/Assertions.h b/third_party/WebKit/Source/wtf/Assertions.h
index 5904187a..392b24d 100644
--- a/third_party/WebKit/Source/wtf/Assertions.h
+++ b/third_party/WebKit/Source/wtf/Assertions.h

@@ -46,14 +46,8 @@
 #include <windows.h>
 #endif
 
-// Users must test "#if ENABLE(ASSERT)", which helps ensure that code
-// testing this macro has included this header.
-#ifndef ENABLE_ASSERT
-#define ENABLE_ASSERT DCHECK_IS_ON()
-#endif
-
 #ifndef LOG_DISABLED
-#define LOG_DISABLED !ENABLE(ASSERT)
+#define LOG_DISABLED !DCHECK_IS_ON()
 #endif
 
 // These helper functions are always declared, but not necessarily always
@@ -152,7 +146,7 @@
   LAZY_STREAM(logging::LogMessage(file, line, #assertion).stream(), \
               DCHECK_IS_ON() ? !(assertion) : false)
 
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
 #define ASSERT(assertion) DCHECK(assertion)
 #define ASSERT_NOT_REACHED() NOTREACHED()
 #else
@@ -162,7 +156,7 @@
 
 // Users must test "#if ENABLE(SECURITY_ASSERT)", which helps ensure
 // that code testing this macro has included this header.
-#if defined(ADDRESS_SANITIZER) || ENABLE(ASSERT)
+#if defined(ADDRESS_SANITIZER) || DCHECK_IS_ON()
 #define ENABLE_SECURITY_ASSERT 1
 #else
 #define ENABLE_SECURITY_ASSERT 0

diff --git a/third_party/WebKit/Source/wtf/AssertionsTest.cpp b/third_party/WebKit/Source/wtf/AssertionsTest.cpp
index 76fc801..a15d47c 100644
--- a/third_party/WebKit/Source/wtf/AssertionsTest.cpp
+++ b/third_party/WebKit/Source/wtf/AssertionsTest.cpp

@@ -12,7 +12,7 @@
 
 TEST(AssertionsTest, Assertions) {
   ASSERT(true);
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
   EXPECT_DEATH_IF_SUPPORTED(ASSERT(false), "");
   EXPECT_DEATH_IF_SUPPORTED(ASSERT_NOT_REACHED(), "");
 #endif

diff --git a/third_party/WebKit/Source/wtf/dtoa/cached-powers.cc b/third_party/WebKit/Source/wtf/dtoa/cached-powers.cc
index 4bc1a74..97b7e9a 100644
--- a/third_party/WebKit/Source/wtf/dtoa/cached-powers.cc
+++ b/third_party/WebKit/Source/wtf/dtoa/cached-powers.cc

@@ -138,7 +138,7 @@
     const int PowersOfTenCache::kMinDecimalExponent = -348; // kCachedPowers[0].decimal_exponent
     const int PowersOfTenCache::kMaxDecimalExponent = 340; // kCachedPowers[kCachedPowersLength - 1].decimal_exponent
 
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
     static const int kCachedPowersLength = ARRAY_SIZE(kCachedPowers);
 
     // Check that the static constants match the values in kCachedPowers.
@@ -155,20 +155,20 @@
                                                                 int max_exponent,
                                                                 DiyFp* power,
                                                                 int* decimal_exponent) {
-#if ENABLE(ASSERT)
-        validateStaticConstants();
+#if DCHECK_IS_ON()
+      validateStaticConstants();
 #endif
-        const int kQ = DiyFp::kSignificandSize;
-        double k = ceil((min_exponent + kQ - 1) * kD_1_LOG2_10);
-        int foo = kCachedPowersOffset;
-        int index =
-        (foo + static_cast<int>(k) - 1) / kDecimalExponentDistance + 1;
-        ASSERT(0 <= index && index < kCachedPowersLength);
-        CachedPower cached_power = kCachedPowers[index];
-        ASSERT(min_exponent <= cached_power.binary_exponent);
-        ASSERT(cached_power.binary_exponent <= max_exponent);
-        *decimal_exponent = cached_power.decimal_exponent;
-        *power = DiyFp(cached_power.significand, cached_power.binary_exponent);
+      const int kQ = DiyFp::kSignificandSize;
+      double k = ceil((min_exponent + kQ - 1) * kD_1_LOG2_10);
+      int foo = kCachedPowersOffset;
+      int index =
+          (foo + static_cast<int>(k) - 1) / kDecimalExponentDistance + 1;
+      ASSERT(0 <= index && index < kCachedPowersLength);
+      CachedPower cached_power = kCachedPowers[index];
+      ASSERT(min_exponent <= cached_power.binary_exponent);
+      ASSERT(cached_power.binary_exponent <= max_exponent);
+      *decimal_exponent = cached_power.decimal_exponent;
+      *power = DiyFp(cached_power.significand, cached_power.binary_exponent);
     }
 
 
@@ -177,7 +177,7 @@
                                                             int* found_exponent) {
         ASSERT(kMinDecimalExponent <= requested_exponent);
         ASSERT(requested_exponent < kMaxDecimalExponent + kDecimalExponentDistance);
-#if ENABLE(ASSERT)
+#if DCHECK_IS_ON()
         validateStaticConstants();
 #endif
         int index =

diff --git a/tools/mb/mb.py b/tools/mb/mb.py
index 59b820ad..edbb434 100755
--- a/tools/mb/mb.py
+++ b/tools/mb/mb.py

@@ -1060,14 +1060,14 @@
 
     android = 'target_os="android"' in vals['gn_args']
     ozone = 'use_ozone=true' in vals['gn_args']
-    ozone_x11 = (ozone and 'args' in isolate_map[target] and
-                 '--ozone-platform=x11' in isolate_map[target]['args'])
+    chromeos = 'target_os="chromeos"' in vals['gn_args']
 
-    # This needs to mirror the settings in //build/config/ui.gni:
-    # use_x11 = is_linux && !use_ozone || use_ozone && --ozone-platform=x11
-    use_x11 = (self.platform == 'linux2' and
+    # This should be true if tests with type='windowed_test_launcher' are
+    # expected to run using xvfb. For example, Linux Desktop, X11 CrOS and
+    # Ozone CrOS builds.
+    use_xvfb = (self.platform == 'linux2' and
                not android and
-               (ozone_x11 or not ozone))
+               ((not ozone) or (ozone and chromeos)))
 
     asan = 'is_asan=true' in vals['gn_args']
     msan = 'is_msan=true' in vals['gn_args']
@@ -1103,7 +1103,7 @@
       ]
       cmdline = (['./../../build/android/test_wrapper/logdog_wrapper.py']
                  + logdog_command + test_cmdline)
-    elif use_x11 and test_type == 'windowed_test_launcher':
+    elif use_xvfb and test_type == 'windowed_test_launcher':
       extra_files = [
           '../../testing/test_env.py',
           '../../testing/xvfb.py',

diff --git a/tools/metrics/histograms/histograms.xml b/tools/metrics/histograms/histograms.xml
index 78a0d5c2..eb1845a 100644
--- a/tools/metrics/histograms/histograms.xml
+++ b/tools/metrics/histograms/histograms.xml

@@ -51858,6 +51858,17 @@
   </summary>
 </histogram>
 
+<histogram base="true" name="PurgeAndSuspend.Experimental.MemoryGrowth"
+    units="KB">
+<!-- Name completed by histogram_suffixes name="PurgeAndSuspendExperiment" -->
+
+  <owner>tasak@google.org</owner>
+  <summary>
+    The growth of the background renderer's memory usage after a background
+    renderer is purged. This is recorded 5, 10 and 15 minutes after the purge.
+  </summary>
+</histogram>
+
 <histogram name="PurgeAndSuspend.Memory.BlinkGCKB" units="KB">
   <owner>tasak@google.com</owner>
   <summary>
@@ -89391,8 +89402,7 @@
   <int value="1769" label="DocumentCompleteURLHTTPContainingLessThan"/>
   <int value="1770"
       label="DocumentCompleteURLHTTPContainingNewlineAndLessThan"/>
-  <int value="1771"
-      label="DocumentCompleteURLNonHTTPContainingNewlineOrLessThan"/>
+  <int value="1771" label="DocumentCompleteURLNonHTTPContainingNewline"/>
   <int value="1772" label="CSSSelectorInternalMediaControlsTextTrackList"/>
   <int value="1773" label="CSSSelectorInternalMediaControlsTextTrackListItem"/>
   <int value="1774"
@@ -115984,6 +115994,20 @@
   <affected-histogram name="PLT.BeginToFinish_NormalLoad"/>
 </histogram_suffixes>
 
+<histogram_suffixes name="PurgeAndSuspendExperiment" separator=".">
+  <suffix name="BlinkGCKB" label="Constrained to the BlinkGC allocator"/>
+  <suffix name="DiscardableKB" label="Constrained to discardable memory usage"/>
+  <suffix name="PartitionAllocKB"
+      label="Constrained to PartitionAlloc allocator"/>
+  <suffix name="MallocKB" label="Constrained to malloc memory usage"/>
+  <suffix name="TotalAllocatedKB"
+      label="Summed over the PartitionAlloc, malloc, discardable memory,
+             mainThreadIsolate() and BlinkGC allocators"/>
+  <suffix name="V8MainThreadIsolateKB"
+      label="Constrained to memory usage by mainThreadIsolate()"/>
+  <affected-histogram name="PurgeAndSuspend.Experimental.MemoryGrowth"/>
+</histogram_suffixes>
+
 <histogram_suffixes name="QueryTimeSuffix" separator=".">
   <suffix name="0" label="N = 0"/>
   <suffix name="1" label="N = 1"/>

diff --git a/ui/base/clipboard/clipboard_aurax11.cc b/ui/base/clipboard/clipboard_aurax11.cc
index 9a353a1..fe05be26 100644
--- a/ui/base/clipboard/clipboard_aurax11.cc
+++ b/ui/base/clipboard/clipboard_aurax11.cc

@@ -18,7 +18,7 @@
 #include "base/macros.h"
 #include "base/memory/ref_counted_memory.h"
 #include "base/memory/singleton.h"
-#include "base/metrics/histogram.h"
+#include "base/metrics/histogram_macros.h"
 #include "base/stl_util.h"
 #include "base/strings/utf_string_conversions.h"
 #include "third_party/skia/include/core/SkBitmap.h"

diff --git a/ui/base/x/x11_util.cc b/ui/base/x/x11_util.cc
index e0cb8d7..43bb7d7 100644
--- a/ui/base/x/x11_util.cc
+++ b/ui/base/x/x11_util.cc

@@ -28,7 +28,7 @@
 #include "base/macros.h"
 #include "base/memory/singleton.h"
 #include "base/message_loop/message_loop.h"
-#include "base/metrics/histogram.h"
+#include "base/metrics/histogram_macros.h"
 #include "base/single_thread_task_runner.h"
 #include "base/stl_util.h"
 #include "base/strings/string_number_conversions.h"

diff --git a/ui/gl/BUILD.gn b/ui/gl/BUILD.gn
index 48ad007..360551d 100644
--- a/ui/gl/BUILD.gn
+++ b/ui/gl/BUILD.gn

@@ -411,24 +411,21 @@
   ]
 }
 
-# Non-Ozone trybots end up trying to build this when building "all" and failing
-# when X11 isn't there.
-if (ozone_platform_x11) {
-  group("gl_unittests_ozonex") {
-    testonly = true
-    data_deps = [
-      ":gl_unittests",
-    ]
-  }
+# We can't run this test on real Chrome OS hardware for Ozone, so new target.
+group("gl_unittests_ozone") {
+  testonly = true
+  data_deps = [
+    ":gl_unittests",
+  ]
+}
 
-  # TODO(GYP_GONE): Delete this after we've converted everything to GN.
-  # The _run targets exist only for compatibility w/ GYP.
-  group("gl_unittests_ozonex_run") {
-    testonly = true
-    deps = [
-      ":gl_unittests_ozonex",
-    ]
-  }
+# TODO(GYP_GONE): Delete this after we've converted everything to GN.
+# The _run targets exist only for compatibility w/ GYP.
+group("gl_unittests_ozone_run") {
+  testonly = true
+  deps = [
+    ":gl_unittests_ozone",
+  ]
 }
 
 if (is_android) {

diff --git a/ui/keyboard/keyboard_util.cc b/ui/keyboard/keyboard_util.cc
index 3523f0d..1f4069fc 100644
--- a/ui/keyboard/keyboard_util.cc
+++ b/ui/keyboard/keyboard_util.cc

@@ -9,7 +9,7 @@
 #include "base/command_line.h"
 #include "base/lazy_instance.h"
 #include "base/logging.h"
-#include "base/metrics/histogram.h"
+#include "base/metrics/histogram_macros.h"
 #include "base/strings/string16.h"
 #include "media/audio/audio_manager.h"
 #include "ui/aura/client/aura_constants.h"

diff --git a/ui/views/controls/scrollbar/overlay_scroll_bar.cc b/ui/views/controls/scrollbar/overlay_scroll_bar.cc
index 5ea32a4..8a93b23 100644
--- a/ui/views/controls/scrollbar/overlay_scroll_bar.cc
+++ b/ui/views/controls/scrollbar/overlay_scroll_bar.cc

@@ -149,15 +149,8 @@
   thumb->SetBoundsRect(thumb_bounds);
 }
 
-bool OverlayScrollBar::CanAcceptEvent(const ui::Event& event) {
-  return layer()->opacity() > 0 && BaseScrollBar::CanAcceptEvent(event);
-}
-
 void OverlayScrollBar::OnMouseEntered(const ui::MouseEvent& event) {
-  // Note that events are only accepted when the scrollbar is already visible
-  // (due to a change in the scroll value). Don't let the scrollbar vanish from
-  // under the mouse pointer.
-  hide_timer_.Stop();
+  Show();
 }
 
 void OverlayScrollBar::OnMouseExited(const ui::MouseEvent& event) {

diff --git a/ui/views/controls/scrollbar/overlay_scroll_bar.h b/ui/views/controls/scrollbar/overlay_scroll_bar.h
index 5a21d424..5e4dac9 100644
--- a/ui/views/controls/scrollbar/overlay_scroll_bar.h
+++ b/ui/views/controls/scrollbar/overlay_scroll_bar.h

@@ -27,7 +27,6 @@
 
   // View overrides:
   void Layout() override;
-  bool CanAcceptEvent(const ui::Event& event) override;
   void OnMouseEntered(const ui::MouseEvent& event) override;
   void OnMouseExited(const ui::MouseEvent& event) override;
 

diff --git a/url/third_party/mozilla/url_parse.cc b/url/third_party/mozilla/url_parse.cc
index 60aeb05..41768601 100644
--- a/url/third_party/mozilla/url_parse.cc
+++ b/url/third_party/mozilla/url_parse.cc

@@ -690,8 +690,7 @@
 
 }  // namespace
 
-Parsed::Parsed() : inner_parsed_(NULL) {
-}
+Parsed::Parsed() : whitespace_removed(false), inner_parsed_(NULL) {}
 
 Parsed::Parsed(const Parsed& other) :
     scheme(other.scheme),

diff --git a/url/third_party/mozilla/url_parse.h b/url/third_party/mozilla/url_parse.h
index 222d605..968578ba 100644
--- a/url/third_party/mozilla/url_parse.h
+++ b/url/third_party/mozilla/url_parse.h

@@ -177,6 +177,9 @@
   // the string with the scheme stripped off.
   Component GetContent() const;
 
+  // True if whitespace was removed from the URL during parsing.
+  bool whitespace_removed;
+
   // This is used for nested URL types, currently only filesystem.  If you
   // parse a filesystem URL, the resulting Parsed will have a nested
   // inner_parsed_ to hold the parsed inner URL's component information.

diff --git a/url/url_util.cc b/url/url_util.cc
index 867754f..2c8d697 100644
--- a/url/url_util.cc
+++ b/url/url_util.cc

@@ -199,8 +199,13 @@
   // Remove any whitespace from the middle of the relative URL if necessary.
   // Possibly this will result in copying to the new buffer.
   RawCanonOutputT<CHAR> whitespace_buffer;
-  if (whitespace_policy == REMOVE_WHITESPACE)
-    spec = RemoveURLWhitespace(spec, spec_len, &whitespace_buffer, &spec_len);
+  if (whitespace_policy == REMOVE_WHITESPACE) {
+    int original_len = spec_len;
+    spec =
+        RemoveURLWhitespace(spec, original_len, &whitespace_buffer, &spec_len);
+    if (spec_len != original_len)
+      output_parsed->whitespace_removed = true;
+  }
 
   Parsed parsed_input;
 #ifdef WIN32
@@ -280,6 +285,9 @@
   const CHAR* relative = RemoveURLWhitespace(in_relative, in_relative_length,
                                              &whitespace_buffer,
                                              &relative_length);
+  if (in_relative_length != relative_length)
+    output_parsed->whitespace_removed = true;
+
   bool base_is_authority_based = false;
   bool base_is_hierarchical = false;
   if (base_spec &&