Devirtualize Document class type checking

Source/core/svg/SVGDocument.h

 /*
  * Copyright (C) 2004, 2005 Nikolas Zimmermann <zimmermann@kde.org>
  * Copyright (C) 2004, 2005, 2006, 2007 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 33 matching lines @@
     void dispatchScrollEvent();
 
     bool zoomAndPanEnabled() const;
 
     void startPan(const FloatPoint& start);
     void updatePan(const FloatPoint& pos) const;
 
 private:
     SVGDocument(Frame*, const KURL&);
 
-    virtual bool isSVGDocument() const { return true; }
-
     virtual bool childShouldCreateRenderer(const NodeRenderingContext&) const;
 
     FloatPoint m_translate;
 };
 
 inline SVGDocument* toSVGDocument(Document* document)
 {
     ASSERT_WITH_SECURITY_IMPLICATION(!document || document->isSVGDocument());
     return static_cast<SVGDocument*>(document);
 }
 
 inline const SVGDocument* toSVGDocument(const Document* document)
 {
     ASSERT_WITH_SECURITY_IMPLICATION(!document || document->isSVGDocument());
     return static_cast<const SVGDocument*>(document);
 }
 
 // This will catch anyone doing an unnecessary cast.
 void toSVGDocument(const SVGDocument*);
 
 } // namespace WebCore
 
 #endif // ENABLE(SVG)
 #endif // SVGDocument_h
 
 // vim:ts=4:noet