FINALizing of the Node hierarchy.

Source/core/html/MediaDocument.h

 /*
  * Copyright (C) 2008,2009 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 MediaDocument_h
 #define MediaDocument_h
 
 #include "HTMLDocument.h"
 
 namespace WebCore {
 
-class MediaDocument : public HTMLDocument {
+class MediaDocument FINAL : public HTMLDocument {
 public:
     static PassRefPtr<MediaDocument> create(Frame* frame, const KURL& url)
     {
         return adoptRef(new MediaDocument(frame, url));
     }
     virtual ~MediaDocument();
 
     void mediaElementSawUnsupportedTracks();
 
 private:
@@ skipping 20 matching lines @@
     ASSERT_WITH_SECURITY_IMPLICATION(!document || document->isMediaDocument());
     return static_cast<const MediaDocument*>(document);
 }
 
 // This will catch anyone doing an unnecessary cast.
 void toMediaDocument(const MediaDocument*);
 
 }
 
 #endif