Update Event classes to use OVERRIDE / FINAL when needed

Source/core/events/MutationEvent.h

 /*
  * Copyright (C) 2001 Peter Kelly (pmk@post.com)
  * Copyright (C) 2001 Tobias Anton (anton@stud.fbi.fh-darmstadt.de)
  * Copyright (C) 2006 Samuel Weinig (sam.weinig@gmail.com)
  * Copyright (C) 2003, 2004, 2005, 2006, 2008 Apple Inc. All rights reserved.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
  * version 2 of the License, or (at your option) any later version.
@@ skipping 11 matching lines @@
  */
 
 #ifndef MutationEvent_h
 #define MutationEvent_h
 
 #include "core/events/Event.h"
 #include "core/dom/Node.h"
 
 namespace WebCore {
 
-    class MutationEvent : public Event {
+    class MutationEvent FINAL : public Event {
     public:
         virtual ~MutationEvent();
 
         enum attrChangeType {
             MODIFICATION    = 1,
             ADDITION        = 2,
             REMOVAL         = 3
         };
 
         static PassRefPtr<MutationEvent> create()
@@ skipping 10 matching lines @@
         void initMutationEvent(const AtomicString& type, bool canBubble, bool cancelable, PassRefPtr<Node> relatedNode,
                                const String& prevValue, const String& newValue,
                                const String& attrName, unsigned short attrChange);
 
         Node* relatedNode() const { return m_relatedNode.get(); }
         String prevValue() const { return m_prevValue; }
         String newValue() const { return m_newValue; }
         String attrName() const { return m_attrName; }
         unsigned short attrChange() const { return m_attrChange; }
 
-        virtual const AtomicString& interfaceName() const;
+        virtual const AtomicString& interfaceName() const OVERRIDE;
 
     private:
         MutationEvent();
         MutationEvent(const AtomicString& type, bool canBubble, bool cancelable, PassRefPtr<Node> relatedNode,
                       const String& prevValue, const String& newValue,
                       const String& attrName, unsigned short attrChange);
 
         RefPtr<Node> m_relatedNode;
         String m_prevValue;
         String m_newValue;
         String m_attrName;
         unsigned short m_attrChange;
     };
 
 } // namespace WebCore
 
 #endif // MutationEvent_h