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

Source/core/html/HTMLTableElement.cpp

 /*
  * Copyright (C) 1997 Martin Jones (mjones@kde.org)
  *           (C) 1997 Torben Weis (weis@kde.org)
  *           (C) 1998 Waldo Bastian (bastian@kde.org)
  *           (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  * Copyright (C) 2003, 2004, 2005, 2006, 2008, 2010, 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
@@ skipping 48 matching lines @@
     ScriptWrappable::init(this);
 }
 
 PassRefPtr<HTMLTableElement> HTMLTableElement::create(Document& document)
 {
     return adoptRef(new HTMLTableElement(document));
 }
 
 HTMLTableCaptionElement* HTMLTableElement::caption() const
 {
-    for (Element* child = ElementTraversal::firstWithin(*this); child; child = ElementTraversal::nextSibling(*child)) {
-        if (child->hasTagName(captionTag))
-            return toHTMLTableCaptionElement(child);
-    }
-    return 0;
+    return Traversal<HTMLTableCaptionElement>::firstChild(*this);
 }
 
 void HTMLTableElement::setCaption(PassRefPtr<HTMLTableCaptionElement> newCaption, ExceptionState& exceptionState)
 {
     deleteCaption();
     insertBefore(newCaption, firstChild(), exceptionState);
 }
 
 HTMLTableSectionElement* HTMLTableElement::tHead() const
 {
@@ skipping 469 matching lines @@
 {
     return getAttribute(rulesAttr);
 }
 
 const AtomicString& HTMLTableElement::summary() const
 {
     return getAttribute(summaryAttr);
 }
 
 }