[Autoplay] Add histogram metrics for cross-origin autoplay muted experiment

We have already landed rappor metrics for cross-origin autoplay muted
experiment, we should land corresponding histogram metrics as well.

BUG=672526

Review-Url: https://codereview.chromium.org/2576463002
Cr-Commit-Position: refs/heads/master@{#438222}

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

@@ -97,6 +97,11 @@ void AutoplayUmaHelper::onAutoplayInitiated(AutoplaySource source) {
 
 void AutoplayUmaHelper::recordCrossOriginAutoplayResult(
     CrossOriginAutoplayResult result) {
+  DEFINE_STATIC_LOCAL(
+      EnumerationHistogram, autoplayResultHistogram,
+      ("Media.Autoplay.CrossOrigin.Result",
+       static_cast<int>(CrossOriginAutoplayResult::NumberOfResults)));
+
   if (!m_element->isHTMLVideoElement())
     return;
   if (!m_element->isInCrossOriginFrame())
@@ -117,6 +122,7 @@ void AutoplayUmaHelper::recordCrossOriginAutoplayResult(
       Platform::current()->recordRapporURL(
           "Media.Autoplay.CrossOrigin.Allowed.TopLevelFrame",
           m_element->document().topDocument().url());
+      autoplayResultHistogram.count(static_cast<int>(result));
       m_recordedCrossOriginAutoplayResults.insert(result);
       break;
     case CrossOriginAutoplayResult::AutoplayBlocked:
@@ -126,6 +132,7 @@ void AutoplayUmaHelper::recordCrossOriginAutoplayResult(
       Platform::current()->recordRapporURL(
           "Media.Autoplay.CrossOrigin.Blocked.TopLevelFrame",
           m_element->document().topDocument().url());
+      autoplayResultHistogram.count(static_cast<int>(result));
       m_recordedCrossOriginAutoplayResults.insert(result);
       break;
     case CrossOriginAutoplayResult::PlayedWithGesture:
@@ -143,6 +150,22 @@ void AutoplayUmaHelper::recordCrossOriginAutoplayResult(
           "Media.Autoplay.CrossOrigin.PlayedWithGestureAfterBlock."
           "TopLevelFrame",
           m_element->document().topDocument().url());
+      autoplayResultHistogram.count(static_cast<int>(result));
+      m_recordedCrossOriginAutoplayResults.insert(result);
+      break;
+    case CrossOriginAutoplayResult::UserPaused:
+      if (!shouldRecordUserPausedAutoplayingCrossOriginVideo())
+        return;
+      if (m_element->ended() || m_element->seeking())
+        return;
+      Platform::current()->recordRapporURL(
+          "Media.Autoplay.CrossOrigin.UserPausedAutoplayingVideo.ChildFrame",
+          m_element->document().url());
+      Platform::current()->recordRapporURL(
+          "Media.Autoplay.CrossOrigin.UserPausedAutoplayingVideo."
+          "TopLevelFrame",
+          m_element->document().topDocument().url());
+      autoplayResultHistogram.count(static_cast<int>(result));
       m_recordedCrossOriginAutoplayResults.insert(result);
       break;
     default:
@@ -305,21 +328,7 @@ void AutoplayUmaHelper::maybeStopRecordingMutedVideoOffscreenDuration() {
 }
 
 void AutoplayUmaHelper::maybeRecordUserPausedAutoplayingCrossOriginVideo() {
-  if (!shouldRecordUserPausedAutoplayingCrossOriginVideo())
-    return;
-
-  if (m_element->ended() || m_element->seeking())
-    return;
-
-  Platform::current()->recordRapporURL(
-      "Media.Autoplay.CrossOrigin.UserPausedAutoplayingVideo.ChildFrame",
-      m_element->document().url());
-  Platform::current()->recordRapporURL(
-      "Media.Autoplay.CrossOrigin.UserPausedAutoplayingVideo."
-      "TopLevelFrame",
-      m_element->document().topDocument().url());
-
-  m_hasRecordedUserPausedAutoplayingCrossOriginVideo = true;
+  recordCrossOriginAutoplayResult(CrossOriginAutoplayResult::UserPaused);
   maybeUnregisterMediaElementPauseListener();
 }
 
@@ -346,7 +355,8 @@ bool AutoplayUmaHelper::shouldRecordUserPausedAutoplayingCrossOriginVideo()
     const {
   return m_element->isInCrossOriginFrame() && m_element->isHTMLVideoElement() &&
          m_source != AutoplaySource::NumberOfSources &&
-         !m_hasRecordedUserPausedAutoplayingCrossOriginVideo;
+         !m_recordedCrossOriginAutoplayResults.count(
+             CrossOriginAutoplayResult::UserPaused);
 }
 
 DEFINE_TRACE(AutoplayUmaHelper) {

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

@@ -41,9 +41,12 @@ enum AutoplayBlockedReason {
 };
 
 enum class CrossOriginAutoplayResult {
-  AutoplayAllowed,
-  AutoplayBlocked,
-  PlayedWithGesture,
+  AutoplayAllowed = 0,
+  AutoplayBlocked = 1,
+  PlayedWithGesture = 2,
+  UserPaused = 3,
+  // Keep at the end.
+  NumberOfResults = 4,
 };
 
 class Document;
@@ -130,9 +133,6 @@ class CORE_EXPORT AutoplayUmaHelper : public EventListener,
 
   std::set<CrossOriginAutoplayResult> m_recordedCrossOriginAutoplayResults;
 
-  // Whether the UMA helper has recorded user pausing a cross-origin video.
-  bool m_hasRecordedUserPausedAutoplayingCrossOriginVideo;
-
   // 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.

tools/metrics/histograms/histograms.xml

@@ -24258,6 +24258,16 @@ http://cs/file:chrome/histograms.xml - but prefer this file for new entries.
   </summary>
 </histogram>
 
+<histogram name="Media.Autoplay.CrossOrigin.Result"
+    enum="CrossOriginAutoplayResult">
+  <owner>avayvod@chromium.org</owner>
+  <owner>mlamouri@chromium.org</owner>
+  <owner>zqzhang@chromium.org</owner>
+  <summary>
+    The result of autoplaying video elements in cross-origin iframes.
+  </summary>
+</histogram>
+
 <histogram name="Media.AVDA.FrameSentAsOverlay" enum="BooleanFrameAsOverlay">
   <owner>liberato@chromium.org</owner>
   <summary>
@@ -80443,6 +80453,13 @@ http://cs/file:chrome/histograms.xml - but prefer this file for new entries.
   <int value="8" label="PlayMusic"/>
 </enum>
 
+<enum name="CrossOriginAutoplayResult" type="int">
+  <int value="0" label="Allowed"/>
+  <int value="1" label="Blocked"/>
+  <int value="2" label="PlayedWithGesture"/>
+  <int value="3" label="UserPaused"/>
+</enum>
+
 <enum name="CrosTPMDictionaryAttackResetStatusEnum" type="int">
   <int value="0" label="Reset not necessary"/>
   <int value="1" label="Reset attempt succeeded"/>