Introduce toSVGGradientElement(), use it

Source/core/svg/SVGGradientElement.h

 /*
  * Copyright (C) 2004, 2005, 2006, 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 88 matching lines @@
 
     BEGIN_DECLARE_ANIMATED_PROPERTIES(SVGGradientElement)
         DECLARE_ANIMATED_ENUMERATION(SpreadMethod, spreadMethod, SVGSpreadMethodType)
         DECLARE_ANIMATED_ENUMERATION(GradientUnits, gradientUnits, SVGUnitTypes::SVGUnitType)
         DECLARE_ANIMATED_TRANSFORM_LIST(GradientTransform, gradientTransform)
         DECLARE_ANIMATED_STRING(Href, href)
         DECLARE_ANIMATED_BOOLEAN(ExternalResourcesRequired, externalResourcesRequired)
     END_DECLARE_ANIMATED_PROPERTIES
 };
 
+inline SVGGradientElement* toSVGGradientElement(Node* node)
+{
+    ASSERT_WITH_SECURITY_IMPLICATION(!node || node->hasTagName(SVGNames::radialGradientTag));

[tkent, 2013/07/18 05:47:15]

Looks wrong. We should accept SVGNames::linearGradientTag too.

+    return static_cast<SVGGradientElement*>(node);
+}
+
 } // namespace WebCore
 
 #endif