Introduce toSVGAnimateElement(), and use it

Source/core/svg/SVGAnimateElement.h

 /*
  * Copyright (C) 2004, 2005 Nikolas Zimmermann <zimmermann@kde.org>
  * Copyright (C) 2004, 2005 Rob Buis <buis@kde.org>
  * Copyright (C) 2008 Apple Inc. All rights reserved.
  * Copyright (C) Research In Motion Limited 2011. All rights reserved.
  *
  * 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
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  * Library General Public License for more details.
  *
  * You should have received a copy of the GNU Library General Public License
  * along with this library; see the file COPYING.LIB.  If not, write to
  * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
  * Boston, MA 02110-1301, USA.
  */
 
 #ifndef SVGAnimateElement_h
 #define SVGAnimateElement_h
 
+#include "SVGNames.h"
 #include "core/svg/SVGAnimationElement.h"
 #include "wtf/OwnPtr.h"
 
 namespace WebCore {
 
 class SVGAnimatedProperty;
 class SVGAnimatedType;
 class SVGAnimatedTypeAnimator;
 
 class SVGAnimateElement : public SVGAnimationElement {
@@ skipping 30 matching lines @@
 
     OwnPtr<SVGAnimatedType> m_fromType;
     OwnPtr<SVGAnimatedType> m_toType;
     OwnPtr<SVGAnimatedType> m_toAtEndOfDurationType;
     OwnPtr<SVGAnimatedType> m_animatedType;
 
     SVGElementAnimatedPropertyList m_animatedProperties;
     OwnPtr<SVGAnimatedTypeAnimator> m_animator;
 };
 
+inline SVGAnimateElement* toSVGAnimateElement(Element* element)
+{
+    ASSERT_WITH_SECURITY_IMPLICATION(!element
+        || element->hasTagName(SVGNames::animateTag)
+        || element->hasTagName(SVGNames::animateColorTag)
+        || element->hasTagName(SVGNames::animateTransformTag)
+        || element->hasTagName(SVGNames::setTag));
+    return static_cast<SVGAnimateElement*>(element);
+}
+
 } // namespace WebCore
 
 #endif // SVGAnimateElement_h