Add chrome://flags entry for bloated renderer detection

- Adds chrome://flags entry
- Adds a FeatureFlag
- Make existing Blink flag dependent on the Chrome flag

Bug: 808143

Change-Id: Ib48328a63cda8007cf863741cae92957757538e2
Reviewed-on: https://chromium-review.googlesource.com/1140328
Commit-Queue: Ulan Degenbaev <ulan@chromium.org>
Reviewed-by: Jochen Eisinger <jochen@chromium.org>
Reviewed-by: Michael Lippautz <mlippautz@chromium.org>
Cr-Commit-Position: refs/heads/master@{#576455}

chrome/browser/about_flags.cc

@@ -4113,6 +4113,11 @@ const FeatureEntry kFeatureEntries[] = {
      FEATURE_VALUE_TYPE(app_list::features::kEnableContinueReading)},
 #endif  // OS_CHROMEOS
 
+    {"enable-bloated-renderer-detection",
+     flag_descriptions::kEnableBloatedRendererDetectionName,
+     flag_descriptions::kEnableBloatedRendererDetectionDescription, kOsAll,
+     FEATURE_VALUE_TYPE(features::kBloatedRendererDetection)},
+
     // NOTE: Adding a new flag requires adding a corresponding entry to enum
     // "LoginCustomFlags" in tools/metrics/histograms/enums.xml. See "Flag
     // Histograms" in tools/metrics/histograms/README.md (run the

chrome/browser/flag_descriptions.cc

@@ -65,6 +65,10 @@ const char kEnableBlinkHeapIncrementalMarkingName[] =
 const char kEnableBlinkHeapIncrementalMarkingDescription[] =
     "Enable incremental marking in Blink";
 
+const char kEnableBloatedRendererDetectionName[] = "Bloated renderer detection";
+const char kEnableBloatedRendererDetectionDescription[] =
+    "Enable bloated renderer detection";
+
 const char kSystemTrayUnifiedName[] = "New system menu";
 const char kSystemTrayUnifiedDescription[] =
     "Enable the experimental system menu.";

chrome/browser/flag_descriptions.h

@@ -67,6 +67,9 @@ extern const char kAutomaticPasswordGenerationDescription[];
 extern const char kEnableBlinkHeapIncrementalMarkingName[];
 extern const char kEnableBlinkHeapIncrementalMarkingDescription[];
 
+extern const char kEnableBloatedRendererDetectionName[];
+extern const char kEnableBloatedRendererDetectionDescription[];
+
 extern const char kSystemTrayUnifiedName[];
 extern const char kSystemTrayUnifiedDescription[];
 

content/child/runtime_features.cc

@@ -106,6 +106,9 @@ void SetRuntimeFeaturesDefaultsAndUpdateFromArgs(
   if (base::FeatureList::IsEnabled(features::kBlinkHeapIncrementalMarking))
     WebRuntimeFeatures::EnableBlinkHeapIncrementalMarking(true);
 
+  if (base::FeatureList::IsEnabled(features::kBloatedRendererDetection))
+    WebRuntimeFeatures::EnableBloatedRendererDetection(true);
+
   if (command_line.HasSwitch(switches::kDisableDatabases))
     WebRuntimeFeatures::EnableDatabase(false);
 

content/public/common/content_features.cc

@@ -55,6 +55,10 @@ const base::Feature kAudioServiceOutOfProcess{
 const base::Feature kBlinkHeapIncrementalMarking{
     "BlinkHeapIncrementalMarking", base::FEATURE_DISABLED_BY_DEFAULT};
 
+// Enable bloated renderer detection.
+const base::Feature kBloatedRendererDetection{
+    "BloatedRendererDetection", base::FEATURE_DISABLED_BY_DEFAULT};
+
 // Allows swipe left/right from touchpad change browser navigation. Currently
 // only enabled by default on CrOS.
 const base::Feature kTouchpadOverscrollHistoryNavigation {

content/public/common/content_features.h

@@ -26,6 +26,7 @@ CONTENT_EXPORT extern const base::Feature kAudioServiceAudioStreams;
 CONTENT_EXPORT extern const base::Feature kAudioServiceLaunchOnStartup;
 CONTENT_EXPORT extern const base::Feature kAudioServiceOutOfProcess;
 CONTENT_EXPORT extern const base::Feature kBlinkHeapIncrementalMarking;
+CONTENT_EXPORT extern const base::Feature kBloatedRendererDetection;
 CONTENT_EXPORT extern const base::Feature kBlockCredentialedSubresources;
 CONTENT_EXPORT extern const base::Feature kBrotliEncoding;
 CONTENT_EXPORT extern const base::Feature kCacheInlineScriptCode;

third_party/blink/public/platform/web_runtime_features.h

@@ -75,6 +75,7 @@ class WebRuntimeFeatures {
   BLINK_PLATFORM_EXPORT static void EnableAllowActivationDelegationAttr(bool);
   BLINK_PLATFORM_EXPORT static void EnableAudioOutputDevices(bool);
   BLINK_PLATFORM_EXPORT static void EnableBlinkHeapIncrementalMarking(bool);
+  BLINK_PLATFORM_EXPORT static void EnableBloatedRendererDetection(bool);
   BLINK_PLATFORM_EXPORT static void EnableCacheInlineScriptCode(bool);
   BLINK_PLATFORM_EXPORT static void EnableCanvas2dImageChromium(bool);
   BLINK_PLATFORM_EXPORT static void EnableCSSHexAlphaColor(bool);

third_party/blink/renderer/platform/exported/web_runtime_features.cc

@@ -39,6 +39,10 @@ void WebRuntimeFeatures::EnableBlinkHeapIncrementalMarking(bool enable) {
   RuntimeEnabledFeatures::SetHeapIncrementalMarkingEnabled(enable);
 }
 
+void WebRuntimeFeatures::EnableBloatedRendererDetection(bool enable) {
+  RuntimeEnabledFeatures::SetBloatedRendererDetectionEnabled(enable);
+}
+
 void WebRuntimeFeatures::EnableExperimentalFeatures(bool enable) {
   RuntimeEnabledFeatures::SetExperimentalFeaturesEnabled(enable);
 }

tools/metrics/histograms/enums.xml

@@ -28970,6 +28970,7 @@ from previous Chrome versions.
   <int value="1115476442" label="PolicyTool:disabled"/>
   <int value="1115635149" label="EnableUnifiedMultiDeviceSetup:enabled"/>
   <int value="1116593018" label="CaptureThumbnailOnLoadFinished:disabled"/>
+  <int value="1117795262" label="BloatedRendererDetection:disabled"/>
   <int value="1118109174" label="enable-launcher-search-provider-api"/>
   <int value="1126061778" label="CaptureThumbnailOnLoadFinished:enabled"/>
   <int value="1127183523" label="PassiveEventListenersDueToFling:enabled"/>
@@ -29428,6 +29429,7 @@ from previous Chrome versions.
   <int value="2067735898" label="WebVrAutopresentFromIntent:enabled"/>
   <int value="2069999572"
       label="AllowSignedHTTPExchangeCertsWithoutExtension:disabled"/>
+  <int value="2071229145" label="BloatedRendererDetection:enabled"/>
   <int value="2071340353" label="progress-bar-completion"/>
   <int value="2071461362" label="disable-credit-card-scan"/>
   <int value="2075207488" label="AutomaticPasswordGeneration:disabled"/>