Measure whether muted videos that started playing with play() become visible at some point

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

Index: third_party/WebKit/Source/core/html/HTMLMediaElement.cpp
diff --git a/third_party/WebKit/Source/core/html/HTMLMediaElement.cpp b/third_party/WebKit/Source/core/html/HTMLMediaElement.cpp
index 3983e1b82f1f7f8ba5754617a52b40633a1c087c..5a668c485bcbf0f5fd389b06d200c8c7d5a20c13 100644
--- a/third_party/WebKit/Source/core/html/HTMLMediaElement.cpp
+++ b/third_party/WebKit/Source/core/html/HTMLMediaElement.cpp
@@ -44,6 +44,7 @@
 #include "core/frame/Settings.h"
 #include "core/frame/UseCounter.h"
 #include "core/frame/csp/ContentSecurityPolicy.h"
+#include "core/html/AutoplayUmaHelper.h"
 #include "core/html/HTMLMediaSource.h"
 #include "core/html/HTMLSourceElement.h"
 #include "core/html/HTMLTrackElement.h"
@@ -280,16 +281,6 @@ String preloadTypeToString(WebMediaPlayer::Preload preloadType)
     return String();
 }
 
-// These values are used for histograms. Do not reorder.
-enum AutoplaySource {
-    // Autoplay comes from HTMLMediaElement `autoplay` attribute.
-    AutoplaySourceAttribute = 0,
-    // Autoplay comes from `play()` method.
-    AutoplaySourceMethod = 1,
-    // This enum value must be last.
-    NumberOfAutoplaySources = 2,
-};
-
 } // anonymous namespace
 
 class HTMLMediaElement::AutoplayHelperClientImpl :
@@ -447,6 +438,7 @@ HTMLMediaElement::HTMLMediaElement(const QualifiedName& tagName, Document& docum
     , m_audioSourceNode(nullptr)
     , m_autoplayHelperClient(AutoplayHelperClientImpl::create(this))
     , m_autoplayHelper(AutoplayExperimentHelper::create(m_autoplayHelperClient.get()))
+    , m_autoplayUmaHelper(AutoplayUmaHelper::create(this))
     , m_remotePlaybackClient(nullptr)
     , m_autoplayVisibilityObserver(nullptr)
 {
@@ -490,6 +482,8 @@ void HTMLMediaElement::dispose()
     // See Document::isDelayingLoadEvent().
     // Also see http://crbug.com/275223 for more details.
     clearMediaPlayerAndAudioSourceProviderClientWithoutLocking();
+
+    m_autoplayUmaHelper->onElementDestroyed();
 }
 
 void HTMLMediaElement::didMoveToNewDocument(Document& oldDocument)
@@ -1626,7 +1620,8 @@ void HTMLMediaElement::setReadyState(ReadyState state)
 
         // Check for autoplay, and record metrics about it if needed.
         if (shouldAutoplay(RecordMetricsBehavior::DoRecord)) {
-            recordAutoplaySourceMetric(AutoplaySourceAttribute);
+            recordAutoplaySourceMetric(AutoplaySource::Attribute);
+            m_autoplayUmaHelper->onAutoplayInitiated(AutoplaySource::Attribute);
 
             // If the autoplay experiment says that it's okay to play now,
             // then don't require a user gesture.
@@ -2076,7 +2071,8 @@ Nullable<ExceptionCode> HTMLMediaElement::play()
     m_autoplayHelper->playMethodCalled();
 
     if (!UserGestureIndicator::processingUserGesture()) {
-        recordAutoplaySourceMetric(AutoplaySourceMethod);
+        recordAutoplaySourceMetric(AutoplaySource::Method);
+        m_autoplayUmaHelper->onAutoplayInitiated(AutoplaySource::Method);
         if (isGestureNeededForPlayback()) {
             // If playback is deferred, then don't start playback but don't
             // fail yet either.
@@ -3661,6 +3657,7 @@ DEFINE_TRACE(HTMLMediaElement)
     visitor->trace(m_audioSourceProvider);
     visitor->trace(m_autoplayHelperClient);
     visitor->trace(m_autoplayHelper);
+    visitor->trace(m_autoplayUmaHelper);
     visitor->trace(m_srcObject);
     visitor->trace(m_autoplayVisibilityObserver);
     visitor->template registerWeakMembers<HTMLMediaElement, &HTMLMediaElement::clearWeakMembers>(this);
@@ -3881,18 +3878,18 @@ EnumerationHistogram& HTMLMediaElement::showControlsHistogram() const
     return histogram;
 }
 
-void HTMLMediaElement::recordAutoplaySourceMetric(int source)
+void HTMLMediaElement::recordAutoplaySourceMetric(AutoplaySource source)
 {
-    DEFINE_STATIC_LOCAL(EnumerationHistogram, videoHistogram, ("Media.Video.Autoplay", NumberOfAutoplaySources));
-    DEFINE_STATIC_LOCAL(EnumerationHistogram, mutedVideoHistogram, ("Media.Video.Autoplay.Muted", NumberOfAutoplaySources));
-    DEFINE_STATIC_LOCAL(EnumerationHistogram, audioHistogram, ("Media.Audio.Autoplay", NumberOfAutoplaySources));
+    DEFINE_STATIC_LOCAL(EnumerationHistogram, videoHistogram, ("Media.Video.Autoplay", static_cast<int>(AutoplaySource::NumberOfSources)));
+    DEFINE_STATIC_LOCAL(EnumerationHistogram, mutedVideoHistogram, ("Media.Video.Autoplay.Muted", static_cast<int>(AutoplaySource::NumberOfSources)));
+    DEFINE_STATIC_LOCAL(EnumerationHistogram, audioHistogram, ("Media.Audio.Autoplay", static_cast<int>(AutoplaySource::NumberOfSources)));
 
     if (isHTMLVideoElement()) {
-        videoHistogram.count(source);
+        videoHistogram.count(static_cast<int>(source));
         if (muted())
-            mutedVideoHistogram.count(source);
+            mutedVideoHistogram.count(static_cast<int>(source));
     } else {
-        audioHistogram.count(source);
+        audioHistogram.count(static_cast<int>(source));
     }
 }
 
@@ -3916,6 +3913,7 @@ void HTMLMediaElement::onVisibilityChangedForAutoplay(bool isVisible)
         m_autoplaying = false;
 
         updatePlayState();
+        m_autoplayUmaHelper->onAutoplayStarted();
     }
 
     m_autoplayVisibilityObserver->stop();