Reduce forward declarations in core/rendering

Source/core/rendering/RenderVideo.h

 /*
  * Copyright (C) 2007, 2009, 2010 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 12 matching lines @@
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
 #ifndef RenderVideo_h
 #define RenderVideo_h
 
 #include "core/rendering/RenderMedia.h"
 
 namespace WebCore {
 
-class HTMLMediaElement;
 class HTMLVideoElement;
 
 class RenderVideo FINAL : public RenderMedia {
 public:
     RenderVideo(HTMLVideoElement*);
     virtual ~RenderVideo();
 
     IntRect videoBox() const;
 
     static IntSize defaultSize();
@@ skipping 36 matching lines @@
     bool acceleratedRenderingInUse();
 
     LayoutSize m_cachedImageSize;
 };
 
 DEFINE_RENDER_OBJECT_TYPE_CASTS(RenderVideo, isVideo());
 
 } // namespace WebCore
 
 #endif // RenderVideo_h