Clean up toHTMLFooElement() using DEFINE_NODE_TYPE_CASTS_WITH_FUNCTION

Source/core/html/HTMLVideoElement.h

 /*
  * Copyright (C) 2007, 2008, 2009, 2010 Apple Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 82 matching lines @@
 inline bool isHTMLVideoElement(const Node* node)
 {
     return node->hasTagName(HTMLNames::videoTag);
 }
 
 inline bool isHTMLVideoElement(const Element* element)
 {
     return element->hasTagName(HTMLNames::videoTag);
 }
 
-inline HTMLVideoElement* toHTMLVideoElement(Node* node)
-{
-    ASSERT_WITH_SECURITY_IMPLICATION(!node || isHTMLVideoElement(node));
-    return static_cast<HTMLVideoElement*>(node);
-}
+DEFINE_NODE_TYPE_CASTS(HTMLVideoElement, hasTagName(HTMLNames::videoTag));
 
 } //namespace
 
 #endif