Introduce isHTMLAreaElement and toHTMLAreaElement

Source/core/page/FocusController.cpp

 /*
  * Copyright (C) 2006, 2007 Apple Inc. All rights reserved.
  * Copyright (C) 2008 Nuanti Ltd.
  *
  * 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 832 matching lines @@
 
     if (container->isDocumentNode())
         toDocument(container)->updateLayoutIgnorePendingStylesheets();
         
     // Figure out the starting rect.
     LayoutRect startingRect;
     if (focusedNode) {
         if (!hasOffscreenRect(focusedNode)) {
             container = scrollableEnclosingBoxOrParentFrameForNodeInDirection(direction, focusedNode);
             startingRect = nodeRectInAbsoluteCoordinates(focusedNode, true /* ignore border */);
-        } else if (focusedNode->hasTagName(areaTag)) {
-            HTMLAreaElement* area = static_cast<HTMLAreaElement*>(focusedNode);
+        } else if (isHTMLAreaElement(focusedNode)) {
+            HTMLAreaElement* area = toHTMLAreaElement(focusedNode);
             container = scrollableEnclosingBoxOrParentFrameForNodeInDirection(direction, area->imageElement());
             startingRect = virtualRectForAreaElementAndDirection(area, direction);
         }
     }
 
     bool consumed = false;
     do {
         consumed = advanceFocusDirectionallyInContainer(container, startingRect, direction, event);
         startingRect = nodeRectInAbsoluteCoordinates(container, true /* ignore border */);
         container = scrollableEnclosingBoxOrParentFrameForNodeInDirection(direction, container);
         if (container && container->isDocumentNode())
             toDocument(container)->updateLayoutIgnorePendingStylesheets();
     } while (!consumed && container);
 
     return consumed;
 }
 
 } // namespace WebCore