Pause autoplay muted video when unmuting if there's no user gesture

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 413 matching lines @@
     , m_seeking(false)
     , m_sentStalledEvent(false)
     , m_ignorePreloadNone(false)
     , m_textTracksVisible(false)
     , m_shouldPerformAutomaticTrackSelection(true)
     , m_tracksAreReady(true)
     , m_processingPreferenceChange(false)
     , m_remoteRoutesAvailable(false)
     , m_playingRemotely(false)
     , m_inOverlayFullscreenVideo(false)
+    , m_isAutoplayingMuted(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_autoplayHelperClient(AutoplayHelperClientImpl::create(this))
     , m_autoplayHelper(AutoplayExperimentHelper::create(m_autoplayHelperClient.get()))
     , m_remotePlaybackClient(nullptr)
 {
@@ skipping 1809 matching lines @@
 
 bool HTMLMediaElement::muted() const
 {
     return m_muted;
 }
 
 void HTMLMediaElement::setMuted(bool muted)
 {
     DVLOG(MEDIA_LOG_LEVEL) << "setMuted(" << (void*)this << ", " << boolString(muted) << ")";
 
+    if (UserGestureIndicator::processingUserGesture())
+        unlockUserGesture();
+
     if (m_muted == muted)
         return;
 
     m_muted = muted;
     m_autoplayHelper->mutedChanged();
 
     updateVolume();
 
     if (muted)
         Platform::current()->recordAction(UserMetricsAction("Media_Playback_Mute_On"));
     else
         Platform::current()->recordAction(UserMetricsAction("Media_Playback_Mute_Off"));
 
     scheduleEvent(EventTypeNames::volumechange);
+
+    if (!muted && m_isAutoplayingMuted) {

[foolip, 2016/06/09 11:41:43]

As per https://github.com/whatwg/html/issues/976 I don't think should depend on
whether the reason that we're playing, but rather that when setting muted to
false and it was previously true and there is no user gesture, the internal
pause steps should be run.

That's easy to explain and avoids that extra state bit.

+        // Pause the element autoplayed muted when unmuting if there was no user gesture.
+        if (isLockedPendingUserGesture())
+            pause();
+        m_isAutoplayingMuted = false;
+    }
 }
 
 void HTMLMediaElement::updateVolume()
 {
     if (webMediaPlayer())
         webMediaPlayer()->setVolume(effectiveMediaVolume());
 
     if (mediaControls())
         mediaControls()->updateVolume();
 }
@@ skipping 1377 matching lines @@
 bool HTMLMediaElement::isLockedPendingUserGesture() const
 {
     return m_lockedPendingUserGesture;
 }
 
 void HTMLMediaElement::unlockUserGesture()
 {
     m_lockedPendingUserGesture = false;
 }
 
-bool HTMLMediaElement::isGestureNeededForPlayback() const
+bool HTMLMediaElement::isGestureNeededForPlayback()
 {
+    m_isAutoplayingMuted = false;
+
     if (!m_lockedPendingUserGesture)
         return false;
 
-    if (muted() && RuntimeEnabledFeatures::autoplayMutedVideosEnabled())
+    if (muted() && RuntimeEnabledFeatures::autoplayMutedVideosEnabled()) {
+        m_isAutoplayingMuted = true;
         return false;
+    }
 
     if (m_autoplayHelper->isGestureRequirementOverridden())
         return false;
 
     return true;
 }
 
 void HTMLMediaElement::setNetworkState(NetworkState state)
 {
     if (m_networkState != state) {
@@ skipping 235 matching lines @@
 
 IntRect HTMLMediaElement::AutoplayHelperClientImpl::absoluteBoundingBoxRect() const
 {
     IntRect result;
     if (LayoutObject* object = m_element->layoutObject())
         result = object->absoluteBoundingBoxRect();
     return result;
 }
 
 } // namespace blink