[Android] Added a runtime flag to enable autoplay of muted videos.

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 7beecb9dd4be9a28665ac847fe9e6f45f67b085f..aac7685134bb6ec51f87fe7767f7907c6b686455 100644
--- a/third_party/WebKit/Source/core/html/HTMLMediaElement.cpp
+++ b/third_party/WebKit/Source/core/html/HTMLMediaElement.cpp
@@ -94,7 +94,7 @@
 #include "wtf/text/CString.h"
 #include <limits>
 
-#define MEDIA_LOG_LEVEL 3
+#define MEDIA_LOG_LEVEL 0

[mlamouri (slow - plz ping), 2016/06/07 12:50:41]

Did you mean to change this?

[whywhat, 2016/06/07 14:20:08]

Reverted.

 
 #ifndef LOG_MEDIA_EVENTS
 // Default to not logging events because so many are generated they can overwhelm the rest of
@@ -2264,6 +2264,9 @@ void HTMLMediaElement::setMuted(bool muted)
         Platform::current()->recordAction(UserMetricsAction("Media_Playback_Mute_Off"));
 
     scheduleEvent(EventTypeNames::volumechange);
+
+    if (!UserGestureIndicator::processingUserGesture())
+        pause();

[mlamouri (slow - plz ping), 2016/06/07 12:50:41]

We should only have this behaviour for videos that got autoplayed because they
are muted. Maybe it could be done in a follow-up? :)

[whywhat, 2016/06/07 14:20:08]

Removed.

 }
 
 void HTMLMediaElement::updateVolume()
@@ -3661,8 +3664,16 @@ void HTMLMediaElement::unlockUserGesture()
 
 bool HTMLMediaElement::isGestureNeededForPlayback() const
 {
-    return m_lockedPendingUserGesture
-        && !m_autoplayHelper->isGestureRequirementOverridden();
+    if (!m_lockedPendingUserGesture)
+        return false;
+
+    if (RuntimeEnabledFeatures::videosAsImagesEnabled() && muted())
+        return false;

[mlamouri (slow - plz ping), 2016/06/07 12:50:41]

I would leave this for another CL but you will need to keep track of whether the
media element autoplayed because it was muted.

[whywhat, 2016/06/07 14:20:08]

Ok.

+
+    if (m_autoplayHelper->isGestureRequirementOverridden())
+        return false;
+
+    return true;
 }
 
 void HTMLMediaElement::setNetworkState(NetworkState state)