Add usage MediaCapabilities UsageCounter for origin trial

Bug: 690364
Change-Id: Idab949d70f6da65b4d1b17a445ad1574c0431679
Reviewed-on: https://chromium-review.googlesource.com/775886
Commit-Queue: Chrome Cunningham <chcunningham@chromium.org>
Reviewed-by: Dmitry Gozman <dgozman@chromium.org>
Reviewed-by: Mounir Lamouri <mlamouri@chromium.org>
Cr-Commit-Position: refs/heads/master@{#518454}

third_party/WebKit/Source/modules/media_capabilities/MediaCapabilities.idl

@@ -8,7 +8,7 @@
     Exposed=Window,
     OriginTrialEnabled=MediaCapabilities
 ] interface MediaCapabilities {
-    [CallWith=ScriptState] Promise<MediaCapabilitiesInfo> decodingInfo(MediaDecodingConfiguration configuration);
-    [CallWith=ScriptState] Promise<MediaCapabilitiesInfo> encodingInfo(
+    [CallWith=ScriptState, Measure] Promise<MediaCapabilitiesInfo> decodingInfo(MediaDecodingConfiguration configuration);
+    [CallWith=ScriptState, Measure] Promise<MediaCapabilitiesInfo> encodingInfo(
         MediaEncodingConfiguration configuration);
 };

third_party/WebKit/Source/modules/media_capabilities/MediaCapabilitiesInfo.idl

@@ -8,7 +8,7 @@
     Exposed=Window,
     OriginTrialEnabled=MediaCapabilities
 ] interface MediaCapabilitiesInfo {
-    readonly attribute boolean supported;
-    readonly attribute boolean smooth;
-    readonly attribute boolean powerEfficient;
+    [Measure] readonly attribute boolean supported;
+    [Measure] readonly attribute boolean smooth;
+    [Measure] readonly attribute boolean powerEfficient;
 };

third_party/WebKit/public/platform/web_feature.mojom

@@ -1761,6 +1761,11 @@ enum WebFeature {
   kCSPWithUnsafeEval = 2236,
   kWebAssemblyInstantiation = 2237,
   kV8IndexAccessor = 2238,
+  kV8MediaCapabilities_DecodingInfo_Method = 2239,
+  kV8MediaCapabilities_EncodingInfo_Method = 2240,
+  kV8MediaCapabilitiesInfo_Supported_AttributeGetter = 2241,
+  kV8MediaCapabilitiesInfo_Smooth_AttributeGetter = 2242,
+  kV8MediaCapabilitiesInfo_PowerEfficient_AttributeGetter = 2243,
 
   // Add new features immediately above this line. Don't change assigned
   // numbers of any item, and don't reuse removed slots.

tools/metrics/histograms/enums.xml

@@ -16996,6 +16996,12 @@ Called by update_net_error_codes.py.-->
   <int value="2236" label="CSPWithUnsafeEval"/>
   <int value="2237" label="WebAssemblyInstantiation"/>
   <int value="2238" label="V8IndexAccessor"/>
+  <int value="2239" label="V8MediaCapabilities_DecodingInfo_Method"/>
+  <int value="2240" label="V8MediaCapabilities_EncodingInfo_Method"/>
+  <int value="2241" label="V8MediaCapabilitiesInfo_Supported_AttributeGetter"/>
+  <int value="2242" label="V8MediaCapabilitiesInfo_Smooth_AttributeGetter"/>
+  <int value="2243"
+      label="V8MediaCapabilitiesInfo_PowerEfficient_AttributeGetter"/>
 </enum>
 
 <enum name="FeedbackSource">