Use isHTML*Element() helpers more in the accessibility code

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 149 matching lines @@
 {
     if (!gAccessibilityEnabled)
         return 0;
 
     // get the focused node in the page
     Document* focusedDocument = page->focusController().focusedOrMainFrame()->document();
     Node* focusedNode = focusedDocument->focusedElement();
     if (!focusedNode)
         focusedNode = focusedDocument;
 
-    if (focusedNode->hasTagName(areaTag))
+    if (isHTMLAreaElement(*focusedNode))
         return focusedImageMapUIElement(toHTMLAreaElement(focusedNode));
 
     AXObject* obj = focusedNode->document().axObjectCache()->getOrCreate(focusedNode);
     if (!obj)
         return 0;
 
     if (obj->shouldFocusActiveDescendant()) {
         if (AXObject* descendant = obj->activeDescendant())
             obj = descendant;
     }
@@ skipping 853 matching lines @@
 {
     postPlatformNotification(getOrCreate(scrollView), AXScrollPositionChanged);
 }
 
 void AXObjectCache::handleScrollPositionChanged(RenderObject* renderObject)
 {
     postPlatformNotification(getOrCreate(renderObject), AXScrollPositionChanged);
 }
 
 } // namespace WebCore