[unified-heap] Add browser flags

Adds flags on all browser layers which are used for enabling in a Finch
trial.

Tbr: jochen@chromium.org
Bug: 843903
Change-Id: I50d9aa479b1fb6e27588eae000138564f377b523
Reviewed-on: https://chromium-review.googlesource.com/c/1286854
Commit-Queue: Michael Lippautz <mlippautz@chromium.org>
Reviewed-by: Kentaro Hara <haraken@chromium.org>
Cr-Commit-Position: refs/heads/master@{#600741}

chrome/browser/about_flags.cc

@@ -4468,6 +4468,12 @@ const FeatureEntry kFeatureEntries[] = {
      flag_descriptions::kEnableMediaSessionAshMediaKeysDescription, kOsCrOS,
      FEATURE_VALUE_TYPE(ash::features::kMediaSessionAccelerators)},
 #endif  // defined(OS_CHROMEOS)
+
+    {"enable-blink-heap-unified-garbage-collection",
+     flag_descriptions::kEnableBlinkHeapUnifiedGarbageCollectionName,
+     flag_descriptions::kEnableBlinkHeapUnifiedGarbageCollectionDescription,
+     kOsAll, FEATURE_VALUE_TYPE(features::kBlinkHeapUnifiedGarbageCollection)},
+
 };
 
 class FlagsStateSingleton {

chrome/browser/flag_descriptions.cc

@@ -68,6 +68,11 @@ const char kAutomaticPasswordGenerationDescription[] =
     "Allow Chrome to offer to generate passwords when it detects account "
     "creation pages.";
 
+const char kEnableBlinkHeapUnifiedGarbageCollectionName[] =
+    "Blink Heap Unified Garbage Collection";
+const char kEnableBlinkHeapUnifiedGarbageCollectionDescription[] =
+    "Enable unified garbage collection in Blink";
+
 const char kEnableBloatedRendererDetectionName[] = "Bloated renderer detection";
 const char kEnableBloatedRendererDetectionDescription[] =
     "Enable bloated renderer detection";

chrome/browser/flag_descriptions.h

@@ -67,6 +67,9 @@ extern const char kAppBannersDescription[];
 extern const char kAutomaticPasswordGenerationName[];
 extern const char kAutomaticPasswordGenerationDescription[];
 
+extern const char kEnableBlinkHeapUnifiedGarbageCollectionName[];
+extern const char kEnableBlinkHeapUnifiedGarbageCollectionDescription[];
+
 extern const char kEnableBloatedRendererDetectionName[];
 extern const char kEnableBloatedRendererDetectionDescription[];
 

content/child/runtime_features.cc

@@ -120,6 +120,10 @@ void SetRuntimeFeaturesDefaultsAndUpdateFromArgs(
   WebRuntimeFeatures::EnableBlinkHeapIncrementalMarking(
       base::FeatureList::IsEnabled(features::kBlinkHeapIncrementalMarking));
 
+  WebRuntimeFeatures::EnableBlinkHeapUnifiedGarbageCollection(
+      base::FeatureList::IsEnabled(
+          features::kBlinkHeapUnifiedGarbageCollection));
+
   if (base::FeatureList::IsEnabled(features::kBloatedRendererDetection))
     WebRuntimeFeatures::EnableBloatedRendererDetection(true);
 

content/public/common/content_features.cc

@@ -58,6 +58,10 @@ const base::Feature kBackgroundFetch{"BackgroundFetch",
 const base::Feature kBlinkHeapIncrementalMarking{
     "BlinkHeapIncrementalMarking", base::FEATURE_ENABLED_BY_DEFAULT};
 
+// Enable unified garbage collection in Blink.
+const base::Feature kBlinkHeapUnifiedGarbageCollection{
+    "BlinkHeapUnifiedGarbageCollection", base::FEATURE_DISABLED_BY_DEFAULT};
+
 // Enable bloated renderer detection.
 const base::Feature kBloatedRendererDetection{
     "BloatedRendererDetection", base::FEATURE_DISABLED_BY_DEFAULT};

content/public/common/content_features.h

@@ -27,6 +27,7 @@ CONTENT_EXPORT extern const base::Feature kAudioServiceOutOfProcess;
 CONTENT_EXPORT extern const base::Feature kAwaitOptimization;
 CONTENT_EXPORT extern const base::Feature kBackgroundFetch;
 CONTENT_EXPORT extern const base::Feature kBlinkHeapIncrementalMarking;
+CONTENT_EXPORT extern const base::Feature kBlinkHeapUnifiedGarbageCollection;
 CONTENT_EXPORT extern const base::Feature kBloatedRendererDetection;
 CONTENT_EXPORT extern const base::Feature kBlockCredentialedSubresources;
 CONTENT_EXPORT extern const base::Feature kBrotliEncoding;

third_party/blink/public/platform/web_runtime_features.h

@@ -81,6 +81,8 @@ class WebRuntimeFeatures {
   BLINK_PLATFORM_EXPORT static void EnableAudioOutputDevices(bool);
   BLINK_PLATFORM_EXPORT static void EnableBackgroundFetch(bool);
   BLINK_PLATFORM_EXPORT static void EnableBlinkHeapIncrementalMarking(bool);
+  BLINK_PLATFORM_EXPORT static void EnableBlinkHeapUnifiedGarbageCollection(
+      bool);
   BLINK_PLATFORM_EXPORT static void EnableBloatedRendererDetection(bool);
   BLINK_PLATFORM_EXPORT static void EnableCacheInlineScriptCode(bool);
   BLINK_PLATFORM_EXPORT static void EnableIsolatedCodeCache(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::EnableBlinkHeapUnifiedGarbageCollection(bool enable) {
+  RuntimeEnabledFeatures::SetHeapUnifiedGarbageCollectionEnabled(enable);
+}
+
 void WebRuntimeFeatures::EnableBloatedRendererDetection(bool enable) {
   RuntimeEnabledFeatures::SetBloatedRendererDetectionEnabled(enable);
 }

tools/metrics/histograms/enums.xml

@@ -30245,6 +30245,7 @@ from previous Chrome versions.
   <int value="728656094" label="PasswordForceSaving:disabled"/>
   <int value="730024226" label="enable-out-of-process-pdf"/>
   <int value="730750097" label="PermissionsBlacklist:disabled"/>
+  <int value="731779469" label="BlinkHeapUnifiedGarbageCollection:enabled"/>
   <int value="732703958" label="enable-gesture-tap-highlight"/>
   <int value="734900932" label="RecurrentInterstitialFeature:enabled"/>
   <int value="736911267" label="ExperimentalCrostiniUI:disabled"/>
@@ -30627,6 +30628,7 @@ from previous Chrome versions.
   <int value="1442830837" label="MemoryAblation:disabled"/>
   <int value="1444320426" label="VizHitTestDrawQuad:enabled"/>
   <int value="1452546183" label="PwaPersistentNotification:enabled"/>
+  <int value="1454006695" label="BlinkHeapUnifiedGarbageCollection:disabled"/>
   <int value="1454143461" label="CaptureThumbnailOnNavigatingAway:disabled"/>
   <int value="1454363479" label="disable-storage-manager"/>
   <int value="1454527518" label="ArcNativeBridgeExperiment:enabled"/>