Use DEFINE_NODE_TYPE_CASTS instead of using manual toSVGFooElement()

Source/core/svg/SVGMarkerElement.h

 /*
  * Copyright (C) 2004, 2005, 2006, 2007, 2008 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 147 matching lines @@
     static PassRefPtr<SVGAnimatedProperty> lookupOrCreateOrientTypeWrapper(SVGElement* contextElement);
     SVGMarkerOrientType& orientTypeCurrentValue() const { return m_orientType.value; }
     SVGMarkerOrientType& orientTypeBaseValue() const { return m_orientType.value; }
     void setOrientTypeBaseValue(const SVGMarkerOrientType& type) { m_orientType.value = type; }
     PassRefPtr<SVGAnimatedEnumerationPropertyTearOff<SVGMarkerOrientType> > orientType();
 
 private:
     mutable SVGSynchronizableAnimatedProperty<SVGMarkerOrientType> m_orientType;
 };
 
-inline SVGMarkerElement* toSVGMarkerElement(Node* node)
-{
-    ASSERT_WITH_SECURITY_IMPLICATION(!node || node->hasTagName(SVGNames::markerTag));
-    return static_cast<SVGMarkerElement*>(node);
-}
+DEFINE_NODE_TYPE_CASTS(SVGMarkerElement, hasTagName(SVGNames::markerTag));
 
 }
 
 #endif