Port ParentNode API to ElementTraversal

Source/core/dom/ContainerNode.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2001 Dirk Mueller (mueller@kde.org)
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009 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 862 matching lines @@
 
     if (renderer()->style()->hasAppearance())
         RenderTheme::theme().stateChanged(renderer(), HoverState);
 }
 
 PassRefPtr<HTMLCollection> ContainerNode::children()
 {
     return ensureRareData().ensureNodeLists().addCache<HTMLCollection>(this, NodeChildren);
 }
 
-Element* ContainerNode::firstElementChild() const
-{
-    return ElementTraversal::firstWithin(*this);
-}
-
-Element* ContainerNode::lastElementChild() const
-{
-    Node* n = lastChild();
-    while (n && !n->isElementNode())
-        n = n->previousSibling();
-    return toElement(n);
-}
-
-unsigned ContainerNode::childElementCount() const
-{
-    unsigned count = 0;
-    Node* n = firstChild();
-    while (n) {
-        count += n->isElementNode();
-        n = n->nextSibling();
-    }
-    return count;
-}
-
 unsigned ContainerNode::childNodeCount() const
 {
     unsigned count = 0;
     Node *n;
     for (n = firstChild(); n; n = n->nextSibling())
         count++;
     return count;
 }
 
 Node *ContainerNode::childNode(unsigned index) const
@@ skipping 145 matching lines @@
         return true;
 
     if (node->isElementNode() && toElement(node)->shadow())
         return true;
 
     return false;
 }
 #endif
 
 } // namespace WebCore