Make manual isSVG*Element() helpers as efficient as the generated ones

Source/core/svg/SVGTextPositioningElement.h

 /*
  * Copyright (C) 2004, 2005, 2008 Nikolas Zimmermann <zimmermann@kde.org>
  * Copyright (C) 2004, 2005, 2006, 2008 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 35 matching lines @@
     virtual void svgAttributeChanged(const QualifiedName&) OVERRIDE FINAL;
     virtual bool isTextPositioning() const OVERRIDE FINAL { return true; }
 
     RefPtr<SVGAnimatedLengthList> m_x;
     RefPtr<SVGAnimatedLengthList> m_y;
     RefPtr<SVGAnimatedLengthList> m_dx;
     RefPtr<SVGAnimatedLengthList> m_dy;
     RefPtr<SVGAnimatedNumberList> m_rotate;
 };
 
-inline bool isSVGTextPositioningElement(const Node& node)
+inline bool isSVGTextPositioningElement(const SVGElement& element)
 {
-    return node.isSVGElement() && toSVGElement(node).isTextPositioning();
+    return element.isTextPositioning();
 }
 
-DEFINE_ELEMENT_TYPE_CASTS_WITH_FUNCTION(SVGTextPositioningElement);
+DEFINE_SVGELEMENT_TYPE_CASTS_WITH_FUNCTION(SVGTextPositioningElement);
 
 } // namespace blink
 
 #endif