Remove dead code for reflected attributes on <audio>, <video> and <track>

Source/core/html/HTMLMediaElement.h

 /*
  * 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 116 matching lines @@
     bool paused() const;
     double defaultPlaybackRate() const;
     void setDefaultPlaybackRate(double);
     double playbackRate() const;
     void setPlaybackRate(double);
     void updatePlaybackRate();
     PassRefPtr<TimeRanges> played();
     PassRefPtr<TimeRanges> seekable() const;
     bool ended() const;
     bool autoplay() const;
-    void setAutoplay(bool b);
     bool loop() const;
     void setLoop(bool b);
     void play();
     void pause();
 
 // Statistics
     unsigned webkitAudioDecodedByteCount() const;
     unsigned webkitVideoDecodedByteCount() const;
 
 //  Media Source.
@@ skipping 453 matching lines @@
 inline bool isHTMLMediaElement(const Node& node)
 {
     return node.isElementNode() && toElement(node).isMediaElement();
 }
 
 DEFINE_NODE_TYPE_CASTS_WITH_FUNCTION(HTMLMediaElement);
 
 } //namespace
 
 #endif