Introduce isHTMLAreaElement and toHTMLAreaElement

Source/core/accessibility/AXObjectCache.cpp

 /*
  * Copyright (C) 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
@@ skipping 142 matching lines @@
 {
     if (!gAccessibilityEnabled)
         return 0;
 
     // get the focused node in the page
     Document* focusedDocument = page->focusController()->focusedOrMainFrame()->document();
     Node* focusedNode = focusedDocument->focusedNode();
     if (!focusedNode)
         focusedNode = focusedDocument;
 
-    if (focusedNode->hasTagName(areaTag))
-        return focusedImageMapUIElement(static_cast<HTMLAreaElement*>(focusedNode));
-    
+    if (isHTMLAreaElement(focusedNode))
+        return focusedImageMapUIElement(toHTMLAreaElement(focusedNode));
+
     AccessibilityObject* obj = focusedNode->document()->axObjectCache()->getOrCreate(focusedNode);
     if (!obj)
         return 0;
 
     if (obj->shouldFocusActiveDescendant()) {
         if (AccessibilityObject* descendant = obj->activeDescendant())
             obj = descendant;
     }
 
     // the HTML element, for example, is focusable but has an AX object that is ignored
@@ skipping 845 matching lines @@
 void AXObjectCache::handleScrolledToAnchor(const Node* anchorNode)
 {
     // The anchor node may not be accessible. Post the notification for the
     // first accessible object.
     postPlatformNotification(AccessibilityObject::firstAccessibleObjectFromNode(anchorNode), AXScrolledToAnchor);
 }
 
 } // namespace WebCore
 
 #endif // HAVE(ACCESSIBILITY)