Update remaining HTML classes to use OVERRIDE / FINAL when needed

Source/core/html/shadow/ClearButtonElement.h

 /*
  * Copyright (C) 2013 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.
  * 2.  Redistributions in binary form must reproduce the above copyright
  *     notice, this list of conditions and the following disclaimer in the
@@ skipping 30 matching lines @@
         virtual void clearValue() = 0;
     };
 
     static PassRefPtr<ClearButtonElement> create(Document&, ClearButtonOwner&);
     void releaseCapture();
     void removeClearButtonOwner() { m_clearButtonOwner = 0; }
 
 private:
     ClearButtonElement(Document&, ClearButtonOwner&);
     virtual void detach(const AttachContext& = AttachContext()) OVERRIDE;
-    virtual bool isMouseFocusable() const { return false; }
-    virtual void defaultEventHandler(Event*);
+    virtual bool isMouseFocusable() const OVERRIDE { return false; }
+    virtual void defaultEventHandler(Event*) OVERRIDE;
     virtual bool isClearButtonElement() const OVERRIDE;
 
     ClearButtonOwner* m_clearButtonOwner;
     bool m_capturing;
 };
 
 DEFINE_TYPE_CASTS(ClearButtonElement, Element, element, element->isClearButtonElement(), element.isClearButtonElement());
 
 } // namespace
 
 #endif // ClearButtonElement_h