Record the offscreen playing duration of autoplaying muted videos

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

 /*
  * Copyright (C) 2007, 2008, 2009, 2010, 2011, 2012, 2013 Apple Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 275 matching lines @@
 // 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,
 };
 
+static const double maxUmaDuration = 10000;
+static const double umaBucketCount = 50;
+
 } // anonymous namespace
 
 class HTMLMediaElement::AutoplayHelperClientImpl :
     public AutoplayExperimentHelper::Client {
 
 public:
     static AutoplayHelperClientImpl* create(HTMLMediaElement* element)
     {
         return new AutoplayHelperClientImpl(element);
     }
@@ skipping 135 matching lines @@
     , m_processingPreferenceChange(false)
     , m_remoteRoutesAvailable(false)
     , m_playingRemotely(false)
     , m_inOverlayFullscreenVideo(false)
     , m_audioTracks(AudioTrackList::create(*this))
     , m_videoTracks(VideoTrackList::create(*this))
     , m_textTracks(nullptr)
     , m_playPromiseResolveTask(CancellableTaskFactory::create(this, &HTMLMediaElement::resolveScheduledPlayPromises))
     , m_playPromiseRejectTask(CancellableTaskFactory::create(this, &HTMLMediaElement::rejectScheduledPlayPromises))
     , m_audioSourceNode(nullptr)
+    , m_mutedVideoAutoplayStartTimeMS(0)
+    , m_mutedVideoAutoplayOffscreenDurationMS(0)
+    , m_isVisible(false)
+    , m_isAutoplayFromAttribute(false)
+    , m_autoplayOffscreenVisibilityObserver(nullptr)
     , m_autoplayHelperClient(AutoplayHelperClientImpl::create(this))
     , m_autoplayHelper(AutoplayExperimentHelper::create(m_autoplayHelperClient.get()))
     , m_remotePlaybackClient(nullptr)
     , m_autoplayVisibilityObserver(nullptr)
 {
     ThreadState::current()->registerPreFinalizer(this);
 
     MEDIA_LOG << "HTMLMediaElement(" << (void*)this << ")";
 
     // If any experiment is enabled, then we want to enable a user gesture by
     // default, otherwise the experiment does nothing.
     if ((document.settings() && document.settings()->mediaPlaybackRequiresUserGesture())
         || m_autoplayHelper->isExperimentEnabled()) {
         m_lockedPendingUserGesture = true;
     }
 
     setHasCustomStyleCallbacks();
     addElementToDocumentMap(this, &document);
 
     UseCounter::count(document, UseCounter::HTMLMediaElement);
 }
 
 HTMLMediaElement::~HTMLMediaElement()
 {
+    maybeRecordMutedVideoAutoplayOffscreenDuration();
     MEDIA_LOG << "~HTMLMediaElement(" << (void*)this << ")";
 
     // m_audioSourceNode is explicitly cleared by AudioNode::dispose().
     // Since AudioNode::dispose() is guaranteed to be always called before
     // the AudioNode is destructed, m_audioSourceNode is explicitly cleared
     // even if the AudioNode and the HTMLMediaElement die together.
     DCHECK(!m_audioSourceNode);
 }
 
 void HTMLMediaElement::dispose()
@@ skipping 1148 matching lines @@
 
     if (m_readyState == HAVE_ENOUGH_DATA && oldState < HAVE_ENOUGH_DATA && tracksAreReady) {
         if (oldState <= HAVE_CURRENT_DATA) {
             scheduleEvent(EventTypeNames::canplay);
             if (isPotentiallyPlaying)
                 scheduleNotifyPlaying();
         }
 
         // Check for autoplay, and record metrics about it if needed.
         if (shouldAutoplay(RecordMetricsBehavior::DoRecord)) {
+            m_isAutoplayFromAttribute = true;
             recordAutoplaySourceMetric(AutoplaySourceAttribute);
 
             // If the autoplay experiment says that it's okay to play now,
             // then don't require a user gesture.
             m_autoplayHelper->becameReadyToPlay();
 
             if (!isGestureNeededForPlayback()) {
                 if (isHTMLVideoElement() && muted() && RuntimeEnabledFeatures::autoplayMutedVideosEnabled()) {
                     m_autoplayVisibilityObserver = new ElementVisibilityObserver(this, WTF::bind(&HTMLMediaElement::onVisibilityChangedForAutoplay, wrapPersistent(this)));
                     m_autoplayVisibilityObserver->start();
@@ skipping 430 matching lines @@
     return promise;
 }
 
 Nullable<ExceptionCode> HTMLMediaElement::play()
 {
     MEDIA_LOG << "play(" << (void*)this << ")";
 
     m_autoplayHelper->playMethodCalled();
 
     if (!UserGestureIndicator::processingUserGesture()) {
+        m_isAutoplayFromAttribute = false;
         recordAutoplaySourceMetric(AutoplaySourceMethod);
         if (isGestureNeededForPlayback()) {
             // If playback is deferred, then don't start playback but don't
             // fail yet either.
             if (m_autoplayHelper->isPlaybackDeferred())
                 return nullptr;
 
             // If we're already playing, then this play would do nothing anyway.
             // Call playInternal to handle scheduling the promise resolution.
             if (!m_paused) {
@@ skipping 82 matching lines @@
 
     m_autoplayHelper->pauseMethodCalled();
 
     m_autoplaying = false;
 
     if (!m_paused) {
         m_paused = true;
         scheduleTimeupdateEvent(false);
         scheduleEvent(EventTypeNames::pause);
         scheduleRejectPlayPromises(AbortError);
+        maybeRecordMutedVideoAutoplayOffscreenDuration();
     }
 
     updatePlayState();
 }
 
 void HTMLMediaElement::requestRemotePlayback()
 {
     DCHECK(m_remoteRoutesAvailable);
     webMediaPlayer()->requestRemotePlayback();
     Platform::current()->recordAction(UserMetricsAction("Media_RequestRemotePlayback"));
@@ skipping 693 matching lines @@
         if (loop()) {
             //  then seek to the earliest possible position of the media resource and abort these steps.
             seek(0);
         } else {
             // If the media element has still ended playback, and the direction of playback is still
             // forwards, and paused is false,
             if (!m_paused) {
                 // changes paused to true and fires a simple event named pause at the media element.
                 m_paused = true;
                 scheduleEvent(EventTypeNames::pause);
+                maybeRecordMutedVideoAutoplayOffscreenDuration();
             }
             // Queue a task to fire a simple event named ended at the media element.
             scheduleEvent(EventTypeNames::ended);
             Platform::current()->recordAction(UserMetricsAction("Media_Playback_Ended"));
         }
     }
     updatePlayState();
 }
 
 void HTMLMediaElement::durationChanged()
@@ skipping 743 matching lines @@
     visitor->trace(m_textTracks);
     visitor->trace(m_textTracksWhenResourceSelectionBegan);
     visitor->trace(m_playPromiseResolvers);
     visitor->trace(m_playPromiseResolveList);
     visitor->trace(m_playPromiseRejectList);
     visitor->trace(m_audioSourceProvider);
     visitor->trace(m_autoplayHelperClient);
     visitor->trace(m_autoplayHelper);
     visitor->trace(m_srcObject);
     visitor->trace(m_autoplayVisibilityObserver);
+    visitor->trace(m_autoplayOffscreenVisibilityObserver);
     visitor->template registerWeakMembers<HTMLMediaElement, &HTMLMediaElement::clearWeakMembers>(this);
     Supplementable<HTMLMediaElement>::trace(visitor);
     HTMLElement::trace(visitor);
     ActiveDOMObject::trace(visitor);
 }
 
 DEFINE_TRACE_WRAPPERS(HTMLMediaElement)
 {
     visitor->traceWrappers(m_videoTracks);
     visitor->traceWrappers(m_audioTracks);
@@ skipping 227 matching lines @@
         invalidateCachedTime();
         scheduleEvent(EventTypeNames::play);
         scheduleNotifyPlaying();
         m_autoplaying = false;
 
         updatePlayState();
     }
 
     m_autoplayVisibilityObserver->stop();
     m_autoplayVisibilityObserver = nullptr;
+    m_mutedVideoAutoplayStartTimeMS = monotonicallyIncreasingTimeMS();
+    m_isVisible = true;
+    m_autoplayOffscreenVisibilityObserver = new ElementVisibilityObserver(this, WTF::bind(&HTMLMediaElement::onVisibilityChangedForAutoplayOffscreen, wrapPersistent(this)));
+}
+
+void HTMLMediaElement::onVisibilityChangedForAutoplayOffscreen(bool isVisible)
+{
+    if (isVisible == m_isVisible)
+        return;
+
+    if (isVisible)
+        m_mutedVideoAutoplayStartTimeMS = monotonicallyIncreasingTimeMS();
+    else
+        m_mutedVideoAutoplayOffscreenDurationMS += monotonicallyIncreasingTimeMS() - m_mutedVideoAutoplayStartTimeMS;
+
+    m_isVisible = isVisible;
+}
+
+void HTMLMediaElement::maybeRecordMutedVideoAutoplayOffscreenDuration()
+{
+    if (!m_autoplayOffscreenVisibilityObserver)
+        return;
+
+    double timeDeltaMS = m_mutedVideoAutoplayOffscreenDurationMS;
+    if (timeDeltaMS < 0)
+        timeDeltaMS = 0;
+    if (timeDeltaMS > maxUmaDuration)
+        timeDeltaMS = maxUmaDuration;
+
+    if (m_isAutoplayFromAttribute) {
+        DEFINE_STATIC_LOCAL(CustomCountHistogram, durationHistogram, ("Media.Video.Autoplay.Muted.FromAttribute.OffscreenDuration", 0, maxUmaDuration, umaBucketCount));
+        durationHistogram.count(timeDeltaMS);
+    } else {
+        DEFINE_STATIC_LOCAL(CustomCountHistogram, durationHistogram, ("Media.Video.Autoplay.Muted.FromMethod.OffscreenDuration", 0, maxUmaDuration, umaBucketCount));
+        durationHistogram.count(timeDeltaMS);
+    }
+    m_autoplayOffscreenVisibilityObserver->stop();
+    m_autoplayOffscreenVisibilityObserver = nullptr;
+    m_mutedVideoAutoplayOffscreenDurationMS = 0;
 }
 
 void HTMLMediaElement::clearWeakMembers(Visitor* visitor)
 {
     if (!ThreadHeap::isHeapObjectAlive(m_audioSourceNode)) {
         getAudioSourceProvider().setClient(nullptr);
         m_audioSourceNode = nullptr;
     }
 }
 
@@ skipping 95 matching lines @@
 
 IntRect HTMLMediaElement::AutoplayHelperClientImpl::absoluteBoundingBoxRect() const
 {
     IntRect result;
     if (LayoutObject* object = m_element->layoutObject())
         result = object->absoluteBoundingBoxRect();
     return result;
 }
 
 } // namespace blink