Introduce toHTMLMapElement

Source/core/html/HTMLAreaElement.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  * Copyright (C) 2004, 2005, 2006, 2009, 2011 Apple Inc. 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.
  *
@@ skipping 170 matching lines @@
 
 HTMLImageElement* HTMLAreaElement::imageElement() const
 {
     Element* mapElement = parentElement();
     while (mapElement && !mapElement->hasTagName(mapTag))
         mapElement = mapElement->parentElement();
 
     if (!mapElement)
         return 0;
     
-    return static_cast<HTMLMapElement*>(mapElement)->imageElement();
+    return toHTMLMapElement(mapElement)->imageElement();
 }
 
 bool HTMLAreaElement::isKeyboardFocusable(KeyboardEvent*) const
 {
     return isFocusable();
 }
     
 bool HTMLAreaElement::isMouseFocusable() const
 {
     return isFocusable();
@@ skipping 44 matching lines @@
     // FIXME: This means that an AREA that is not a link cannot be made focusable through contenteditable or tabindex. Is it correct?
     return isLink();
 }
 
 String HTMLAreaElement::target() const
 {
     return getAttribute(targetAttr);
 }
 
 }