Use toSVGPathElement() instead of static_cast<>

Source/core/svg/SVGMPathElement.cpp

 /*
  * Copyright (C) 2007 Eric Seidel <eric@webkit.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,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
@@ skipping 136 matching lines @@
     if (SVGExternalResourcesRequired::isKnownAttribute(attrName))
         return;
 
     ASSERT_NOT_REACHED();
 }
 
 SVGPathElement* SVGMPathElement::pathElement()
 {
     Element* target = targetElementFromIRIString(hrefCurrentValue(), document());
     if (target && target->hasTagName(SVGNames::pathTag))
-        return static_cast<SVGPathElement*>(target);
+        return toSVGPathElement(target);
     return 0;
 }
 
 void SVGMPathElement::targetPathChanged()
 {
     notifyParentOfPathChange(parentNode());
 }
 
 void SVGMPathElement::notifyParentOfPathChange(ContainerNode* parent)
 {
     if (parent && parent->hasTagName(SVGNames::animateMotionTag))
         static_cast<SVGAnimateMotionElement*>(parent)->updateAnimationPath();
 }
 
 } // namespace WebCore