Start separating the text track container from the media controls

Source/core/html/shadow/MediaControlElementTypes.h

 /*
  * Copyright (C) 2008, 2009, 2010, 2011 Apple Inc. All rights reserved.
  * Copyright (C) 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.
@@ skipping 40 matching lines @@
     MediaPauseButton,
     MediaTimelineContainer,
     MediaCurrentTimeDisplay,
     MediaTimeRemainingDisplay,
     MediaControlsPanel,
     MediaVolumeSliderContainer,
     MediaVolumeSlider,
     MediaVolumeSliderThumb,
     MediaFullScreenVolumeSlider,
     MediaFullScreenVolumeSliderThumb,
-    MediaTextTrackDisplayContainer,
     MediaExitFullscreenButton,
     MediaOverlayPlayButton,
     MediaCastOffButton,
     MediaCastOnButton,
     MediaOverlayCastOffButton,
     MediaOverlayCastOnButton,
 };
 
 HTMLMediaElement* toParentMediaElement(Node*);
 inline HTMLMediaElement* toParentMediaElement(LayoutObject* renderer) { return toParentMediaElement(renderer->node()); }
@@ skipping 65 matching lines @@
 protected:
     MediaControlTimeDisplayElement(MediaControls&, MediaControlElementType);
 
 private:
     double m_currentValue;
 };
 
 } // namespace blink
 
 #endif // MediaControlElementTypes_h