Media Controls: make the MediaControlsOverlayPlayButton a runtime enabled flag.

third_party/WebKit/Source/core/html/shadow/MediaControls.cpp

 /*
  * Copyright (C) 2011, 2012 Apple Inc. All rights reserved.
  * Copyright (C) 2011, 2012 Google 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
@@ skipping 204 matching lines @@
 //  +-MediaControlTextTrackListItemInput
 //  |    (-internal-media-controls-text-track-list-item-input)
 //  +-MediaControlTextTrackListItemCaptions
 //  |    (-internal-media-controls-text-track-list-kind-captions)
 //  +-MediaControlTextTrackListItemSubtitles
 //       (-internal-media-controls-text-track-list-kind-subtitles)
 void MediaControls::initializeControls() {
   MediaControlOverlayEnclosureElement* overlayEnclosure =
       MediaControlOverlayEnclosureElement::create(*this);
 
-  if (document().settings() &&
-      document().settings()->getMediaControlsOverlayPlayButtonEnabled()) {
+  if (RuntimeEnabledFeatures::mediaControlsOverlayPlayButtonEnabled()) {
     MediaControlOverlayPlayButtonElement* overlayPlayButton =
         MediaControlOverlayPlayButtonElement::create(*this);
     m_overlayPlayButton = overlayPlayButton;
     overlayEnclosure->appendChild(overlayPlayButton);
   }
 
   MediaControlCastButtonElement* overlayCastButton =
       MediaControlCastButtonElement::create(*this, true);
   m_overlayCastButton = overlayCastButton;
   overlayEnclosure->appendChild(overlayCastButton);
@@ skipping 760 matching lines @@
   visitor->trace(m_overflowList);
   visitor->trace(m_castButton);
   visitor->trace(m_overlayCastButton);
   visitor->trace(m_mediaEventListener);
   visitor->trace(m_windowEventListener);
   visitor->trace(m_orientationLockDelegate);
   HTMLDivElement::trace(visitor);
 }
 
 }  // namespace blink