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..b9cd265bab6ddf6b7a4522b53dde5a244c7cbe5f 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 +1620,7 @@ void HTMLMediaElement::setReadyState(ReadyState state)
 
         // Check for autoplay, and record metrics about it if needed.
         if (shouldAutoplay(RecordMetricsBehavior::DoRecord)) {
-            recordAutoplaySourceMetric(AutoplaySourceAttribute);
+            m_autoplayUmaHelper->onAutoplayInitiated(AutoplaySource::Attribute);

[mlamouri (slow - plz ping), 2016/07/04 15:18:19]

I wonder if we shouldn't move this check to the preload place. Technically, this
is where we decide whether autoplay will be allowed. Though, it's something I've
been looking into for that UMA CL I have pending so feel free to do nothing
about it now :)

[Zhiqiang Zhang (Slow), 2016/07/06 13:55:51]

Acknowledged.

 
             // If the autoplay experiment says that it's okay to play now,
             // then don't require a user gesture.
@@ -2076,7 +2070,7 @@ Nullable<ExceptionCode> HTMLMediaElement::play()
     m_autoplayHelper->playMethodCalled();
 
     if (!UserGestureIndicator::processingUserGesture()) {
-        recordAutoplaySourceMetric(AutoplaySourceMethod);
+        m_autoplayUmaHelper->onAutoplayInitiated(AutoplaySource::Method);
         if (isGestureNeededForPlayback()) {
             // If playback is deferred, then don't start playback but don't
             // fail yet either.
@@ -2132,6 +2126,7 @@ void HTMLMediaElement::playInternal()
         seek(0);
 
     if (m_paused) {
+        m_autoplayUmaHelper->onAutoplayStarted();

[mlamouri (slow - plz ping), 2016/07/04 15:18:19]

Maybe this should be called onPlaybackStart{,ed,ing}, it might not be at all
autoplay related. There are also other places where playback could start.

Crazy idea: can we listen to the playing event? ;) (more seriously, if you
create a PlayingEventLister in autoplayUmaHelper and call
addEventListerer(EventTypeNames::playing, playingEventLister, false), we might
be able to have something very neat :)

[Zhiqiang Zhang (Slow), 2016/07/06 13:55:51]

Using EventListener now :)

         m_paused = false;
         invalidateCachedTime();
         scheduleEvent(EventTypeNames::play);
@@ -2301,9 +2296,9 @@ void HTMLMediaElement::setMuted(bool muted)
     if (wasAutoplayingMuted) {
         if (isGestureNeededForPlayback()) {
             pause();
-            recordAutoplayUnmuteStatus(AutoplayUnmuteActionFailure);
+            m_autoplayUmaHelper->recordAutoplayUnmuteStatus(AutoplayUnmuteActionStatus::Failure);
         } else {
-            recordAutoplayUnmuteStatus(AutoplayUnmuteActionSuccess);
+            m_autoplayUmaHelper->recordAutoplayUnmuteStatus(AutoplayUnmuteActionStatus::Success);
         }
     }
 }
@@ -3661,6 +3656,7 @@ 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);
@@ -3881,28 +3877,6 @@ EnumerationHistogram& HTMLMediaElement::showControlsHistogram() const
     return histogram;
 }
 
-void HTMLMediaElement::recordAutoplaySourceMetric(int 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));
-
-    if (isHTMLVideoElement()) {
-        videoHistogram.count(source);
-        if (muted())
-            mutedVideoHistogram.count(source);
-    } else {
-        audioHistogram.count(source);
-    }
-}
-
-void HTMLMediaElement::recordAutoplayUnmuteStatus(AutoplayUnmuteActionStatus status)
-{
-    DEFINE_STATIC_LOCAL(EnumerationHistogram, autoplayUnmuteHistogram, ("Media.Video.Autoplay.Muted.UnmuteAction", AutoplayUnmuteActionMax));
-
-    autoplayUnmuteHistogram.count(status);
-}
-
 void HTMLMediaElement::onVisibilityChangedForAutoplay(bool isVisible)
 {
     if (!isVisible)
@@ -3916,6 +3890,7 @@ void HTMLMediaElement::onVisibilityChangedForAutoplay(bool isVisible)
         m_autoplaying = false;
 
         updatePlayState();
+        m_autoplayUmaHelper->onAutoplayStarted();
     }

[mlamouri (slow - plz ping), 2016/07/04 15:18:19]

If we are here, the source is unlikely play() so it would be a no-op, right?

[Zhiqiang Zhang (Slow), 2016/07/06 13:55:51]

Since we are using EventListener, there's no problem now.
Removed this line.

 
     m_autoplayVisibilityObserver->stop();