Fix virtual/override/final usage in Source/core/svg/.

Source/core/svg/SVGFEMergeNodeElement.h

 /*
  * Copyright (C) 2004, 2005 Nikolas Zimmermann <zimmermann@kde.org>
  * Copyright (C) 2004, 2005, 2006 Rob Buis <buis@kde.org>
  *
  * 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 21 matching lines @@
     DEFINE_WRAPPERTYPEINFO();
 public:
     DECLARE_NODE_FACTORY(SVGFEMergeNodeElement);
     SVGAnimatedString* in1() { return m_in1.get(); }
 
     DECLARE_VIRTUAL_TRACE();
 
 private:
     explicit SVGFEMergeNodeElement(Document&);
 
-    virtual void svgAttributeChanged(const QualifiedName&) override;
+    void svgAttributeChanged(const QualifiedName&) override;
 
-    virtual bool layoutObjectIsNeeded(const ComputedStyle&) override { return false; }
+    bool layoutObjectIsNeeded(const ComputedStyle&) override { return false; }
 
     RefPtrWillBeMember<SVGAnimatedString> m_in1;
 };
 
 } // namespace blink
 
 #endif // SVGFEMergeNodeElement_h