Use DEFINE_NODE_TYPE_CASTS instead of using manual toSVGFooElement()

Source/core/svg/SVGElement.cpp

 /*
  * Copyright (C) 2004, 2005, 2006, 2007, 2008 Nikolas Zimmermann <zimmermann@kde.org>
  * Copyright (C) 2004, 2005, 2006, 2008 Rob Buis <buis@kde.org>
  * Copyright (C) 2008 Apple Inc. All rights reserved.
  * Copyright (C) 2008 Alp Toker <alp@atoker.com>
  * Copyright (C) 2009 Cameron McCormack <cam@mcc.id.au>
  *
  * 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
@@ skipping 854 matching lines @@
 void SVGElement::sendSVGLoadEventIfPossible(bool sendParentLoadEvents)
 {
     RefPtr<SVGElement> currentTarget = this;
     while (currentTarget && currentTarget->haveLoadedRequiredResources()) {
         RefPtr<Element> parent;
         if (sendParentLoadEvents)
             parent = currentTarget->parentOrShadowHostElement(); // save the next parent to dispatch too incase dispatching the event changes the tree
         if (hasLoadListener(currentTarget.get()))
             currentTarget->dispatchEvent(Event::create(EventTypeNames::load));
         currentTarget = (parent && parent->isSVGElement()) ? static_pointer_cast<SVGElement>(parent) : RefPtr<SVGElement>();
-        SVGElement* element = toSVGElement(currentTarget.get());
+        SVGElement* element = currentTarget.get();
         if (!element || !element->isOutermostSVGSVGElement())
             continue;
 
         // Consider <svg onload="foo()"><image xlink:href="foo.png" externalResourcesRequired="true"/></svg>.
         // If foo.png is not yet loaded, the first SVGLoad event will go to the <svg> element, sent through
         // Document::implicitClose(). Then the SVGLoad event will fire for <image>, once its loaded.
         ASSERT(sendParentLoadEvents);
 
         // If the load event was not sent yet by Document::implicitClose(), but the <image> from the example
         // above, just appeared, don't send the SVGLoad event to the outermost <svg>, but wait for the document
@@ skipping 281 matching lines @@
     }
 
     if (name == classAttr)
         return true;
 
     return animatableAttributes.contains(name);
 }
 #endif
 
 }