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

Source/core/svg/SVGImageLoader.h

 /*
  * Copyright (C) 2006 Alexander Kellett <lypanov@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,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
@@ skipping 17 matching lines @@
 
 class SVGImageLoader final : public ImageLoader {
 public:
     static PassOwnPtrWillBeRawPtr<SVGImageLoader> create(SVGImageElement* element)
     {
         return adoptPtrWillBeNoop(new SVGImageLoader(element));
     }
 
 private:
     explicit SVGImageLoader(SVGImageElement*);
-    virtual void dispatchLoadEvent() override;
+    void dispatchLoadEvent() override;
 };
 
 } // namespace blink
 
 #endif // SVGImageLoader_h