Use new Traversal<HTML*Element> API in HTML code

Source/core/html/HTMLMapElement.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  * Copyright (C) 2004, 2005, 2006, 2007, 2010 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 36 matching lines @@
     return adoptRef(new HTMLMapElement(document));
 }
 
 HTMLMapElement::~HTMLMapElement()
 {
 }
 
 bool HTMLMapElement::mapMouseEvent(LayoutPoint location, const LayoutSize& size, HitTestResult& result)
 {
     HTMLAreaElement* defaultArea = 0;
-    Element* element = this;
-    while ((element = ElementTraversal::next(*element, this))) {
-        if (element->hasTagName(areaTag)) {
-            HTMLAreaElement* areaElt = toHTMLAreaElement(element);
-            if (areaElt->isDefault()) {
-                if (!defaultArea)
-                    defaultArea = areaElt;
-            } else if (areaElt->mapMouseEvent(location, size, result))
-                return true;
+    for (HTMLAreaElement* area = Traversal<HTMLAreaElement>::firstWithin(*this); area; area = Traversal<HTMLAreaElement>::next(*area, this)) {
+        if (area->isDefault()) {
+            if (!defaultArea)
+                defaultArea = area;
+        } else if (area->mapMouseEvent(location, size, result)) {
+            return true;
         }
     }
 
     if (defaultArea) {
         result.setInnerNode(defaultArea);
         result.setURLElement(defaultArea);
     }
     return defaultArea;
 }
 
@@ skipping 55 matching lines @@
 }
 
 void HTMLMapElement::removedFrom(ContainerNode* insertionPoint)
 {
     if (insertionPoint->inDocument())
         treeScope().removeImageMap(this);
     HTMLElement::removedFrom(insertionPoint);
 }
 
 }