Update more svg classes to use OVERRIDE / FINAL when needed

Source/core/svg/SVGElementInstance.h

 /*
  * Copyright (C) 2007, 2008 Nikolas Zimmermann <zimmermann@kde.org>
  * Copyright (C) 2011 Torch Mobile (Beijing) Co. Ltd. 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.
  *
  * This library is distributed in the hope that it will be useful,
@@ skipping 132 matching lines @@
 
 private:
     friend class SVGUseElement;
     friend class TreeShared<SVGElementInstance>;
 
     SVGElementInstance(SVGUseElement*, SVGUseElement*, PassRefPtr<SVGElement> originalElement);
 
     void removedLastRef();
     bool hasTreeSharedParent() const { return !!m_parentInstance; }
 
-    virtual Node* toNode();
+    virtual Node* toNode() OVERRIDE;
 
     void appendChild(PassRefPtr<SVGElementInstance> child);
     void setShadowTreeElement(SVGElement*);
 
     template<class GenericNode, class GenericNodeContainer>
     friend void appendChildToContainer(GenericNode& child, GenericNodeContainer&);
 
     template<class GenericNode, class GenericNodeContainer>
     friend void removeDetachedChildrenInContainer(GenericNodeContainer&);
 
@@ skipping 21 matching lines @@
     SVGElementInstance* m_previousSibling;
     SVGElementInstance* m_nextSibling;
 
     SVGElementInstance* m_firstChild;
     SVGElementInstance* m_lastChild;
 };
 
 } // namespace WebCore
 
 #endif