Add a kWebMeasureMemoryViaPerformanceManager feature flag

The flag guards the new implementation of performance.measureMemory
that queries PerformanceManager in the browser process.

Bug: 1085129
Change-Id: Ic38e5593637bdb894d0780ee5aa463d2844c4bbe
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2428241Reviewed-by: Kentaro Hara <haraken@chromium.org>
Commit-Queue: Ulan Degenbaev <ulan@chromium.org>
Cr-Commit-Position: refs/heads/master@{#810600}

third_party/blink/common/features.cc

@@ -59,9 +59,6 @@ const base::Feature kFreezeUserAgent{"FreezeUserAgent",
 const base::Feature kFtpProtocol{"FtpProtocol",
                                  base::FEATURE_ENABLED_BY_DEFAULT};
 
-const base::Feature kMeasureMemoryExperiment{"MeasureMemoryExperiment",
-                                             base::FEATURE_DISABLED_BY_DEFAULT};
-
 // Enable Display Locking JavaScript APIs.
 const base::Feature kDisplayLocking{"DisplayLocking",
                                     base::FEATURE_DISABLED_BY_DEFAULT};
@@ -201,6 +198,11 @@ const base::Feature kRTCOfferExtmapAllowMixed{
 const base::Feature kV8OptimizeWorkersForPerformance{
     "V8OptimizeWorkersForPerformance", base::FEATURE_ENABLED_BY_DEFAULT};
 
+// Controls whether the implementation of the performance.measureMemory
+// web API uses PerformanceManager or not.
+const base::Feature kWebMeasureMemoryViaPerformanceManager{
+    "WebMeasureMemoryViaPerformanceManager", base::FEATURE_DISABLED_BY_DEFAULT};
+
 // Enables negotiation of experimental multiplex codec in SDP.
 const base::Feature kWebRtcMultiplexCodec{"WebRTC-MultiplexCodec",
                                           base::FEATURE_DISABLED_BY_DEFAULT};

third_party/blink/public/common/features.h

@@ -30,7 +30,6 @@ BLINK_COMMON_EXPORT extern const base::Feature kFtpProtocol;
 BLINK_COMMON_EXPORT extern const base::Feature kImplicitRootScroller;
 BLINK_COMMON_EXPORT extern const base::Feature kCSSOMViewScrollCoordinates;
 BLINK_COMMON_EXPORT extern const base::Feature kDisplayLocking;
-BLINK_COMMON_EXPORT extern const base::Feature kMeasureMemoryExperiment;
 BLINK_COMMON_EXPORT extern const base::Feature kJSONModules;
 BLINK_COMMON_EXPORT extern const base::Feature kForceSynchronousHTMLParsing;
 BLINK_COMMON_EXPORT extern const base::Feature kTopLevelAwait;
@@ -54,6 +53,8 @@ BLINK_COMMON_EXPORT extern const base::Feature kRTCGetDisplayMedia;
 BLINK_COMMON_EXPORT extern const base::Feature kRTCUnifiedPlanByDefault;
 BLINK_COMMON_EXPORT extern const base::Feature kRTCOfferExtmapAllowMixed;
 BLINK_COMMON_EXPORT extern const base::Feature kV8OptimizeWorkersForPerformance;
+BLINK_COMMON_EXPORT extern const base::Feature
+    kWebMeasureMemoryViaPerformanceManager;
 BLINK_COMMON_EXPORT extern const base::Feature kWebRtcMultiplexCodec;
 BLINK_COMMON_EXPORT extern const base::Feature kWebRtcHideLocalIpsWithMdns;