Improve caption button behavior for video player.

third_party/WebKit/Source/core/html/shadow/MediaControlElements.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 167 matching lines @@
   void defaultEventHandler(Event*) override;
 
   void refreshTextTrackListMenu();
 
   // Returns the label for the track when a valid track is passed in and "Off"
   // when the parameter is null.
   String getTextTrackLabel(TextTrack*);
   // Creates the track element in the list when a valid track is passed in and
   // the "Off" item when the parameter is null.
   Element* createTextTrackListItem(TextTrack*);
-
-  void showTextTrackAtIndex(unsigned);
-  void disableShowingTextTracks();
 };
 
 // ----------------------------
 // Represents the overflow menu which is displayed when the width of the media
 // player is small enough that at least two buttons are no longer visible.
 class MediaControlOverflowMenuButtonElement final
     : public MediaControlInputElement {
  public:
   static MediaControlOverflowMenuButtonElement* create(MediaControls&);
 
@@ skipping 165 matching lines @@
  public:
   static MediaControlCurrentTimeDisplayElement* create(MediaControls&);
 
  private:
   explicit MediaControlCurrentTimeDisplayElement(MediaControls&);
 };
 
 }  // namespace blink
 
 #endif  // MediaControlElements_h