Adding Rappor metrics for disabling cross-origin autoplay with sound experiment

third_party/WebKit/Source/core/html/AutoplayUmaHelper.h

Index: third_party/WebKit/Source/core/html/AutoplayUmaHelper.h
diff --git a/third_party/WebKit/Source/core/html/AutoplayUmaHelper.h b/third_party/WebKit/Source/core/html/AutoplayUmaHelper.h
index 7dda64bb56d55bc2b799c5290a8a9b9f2c420e88..bc1d6282bb60ee76a6077df46ff25223e5b492a5 100644
--- a/third_party/WebKit/Source/core/html/AutoplayUmaHelper.h
+++ b/third_party/WebKit/Source/core/html/AutoplayUmaHelper.h
@@ -8,6 +8,8 @@
 #include "core/events/EventListener.h"
 #include "platform/heap/Handle.h"
 
+#include <set>
+
 namespace blink {
 
 // These values are used for histograms. Do not reorder.
@@ -36,6 +38,12 @@ enum AutoplayBlockedReason {
   AutoplayBlockedReasonMax = 3
 };
 
+enum class AutoplayCrossOriginExperimentMetric {

[whywhat, 2016/11/29 21:42:04]

nit: I think we could avoid having experiment and metric in the metric enum
names
First, we may want to upgrade the code to stable if the experiment is successful
(and keep the metrics) - you probably don't want to rename everything then.
Second, Metric is not descriptive for what is being measured.

Maybe something like CrossOriginAutoplayResult?
Similar comment applies to other names in this and the dependent patch.

[Zhiqiang Zhang (Slow), 2016/11/30 17:30:52]

Done.

+  AutoplayAllowed,
+  AutoplayBlocked,
+  PlayedWithGesture,
+};
+
 class Document;
 class ElementVisibilityObserver;
 class HTMLMediaElement;
@@ -50,6 +58,7 @@ class AutoplayUmaHelper final : public EventListener {
 
   void onAutoplayInitiated(AutoplaySource);
 
+  void recordCrossOriginExperimentMetric(AutoplayCrossOriginExperimentMetric);
   void recordAutoplayUnmuteStatus(AutoplayUnmuteActionStatus);
 
   void didMoveToNewDocument(Document& oldDocument);
@@ -108,6 +117,9 @@ class AutoplayUmaHelper final : public EventListener {
   // Whether an autoplaying muted video is visible.
   bool m_isVisible;
 
+  std::set<AutoplayCrossOriginExperimentMetric>
+      m_recordedCrossOriginExperimentMetrics;
+
   // The observer is used to observer an autoplaying muted video changing it's
   // visibility, which is used for offscreen duration UMA.  The UMA is pending
   // for recording as long as this observer is non-null.