Update Event classes to use OVERRIDE / FINAL when needed

Source/core/events/ProgressEvent.h

 /*
  * Copyright (C) 2007, 2008 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 39 matching lines @@
     }
     static PassRefPtr<ProgressEvent> create(const AtomicString& type, const ProgressEventInit& initializer)
     {
         return adoptRef(new ProgressEvent(type, initializer));
     }
 
     bool lengthComputable() const { return m_lengthComputable; }
     unsigned long long loaded() const { return m_loaded; }
     unsigned long long total() const { return m_total; }
 
-    virtual const AtomicString& interfaceName() const;
+    virtual const AtomicString& interfaceName() const OVERRIDE;
 
 protected:
     ProgressEvent();
     ProgressEvent(const AtomicString& type, bool lengthComputable, unsigned long long loaded, unsigned long long total);
     ProgressEvent(const AtomicString&, const ProgressEventInit&);
 
 private:
     bool m_lengthComputable;
     unsigned long long m_loaded;
     unsigned long long m_total;
 };
 }
 
 #endif // ProgressEvent_h