Port Node's previousElementSibling() / nextElementSibling() to ElementTraversal

Source/core/dom/Document.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2001 Dirk Mueller (mueller@kde.org)
  *           (C) 2006 Alexey Proskuryakov (ap@webkit.org)
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009, 2011, 2012 Apple Inc. All rights reserved.
  * Copyright (C) 2008, 2009 Torch Mobile Inc. All rights reserved. (http://www.torchmobile.com/)
  * Copyright (C) 2008, 2009, 2011, 2012 Google Inc. All rights reserved.
  * Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies)
  * Copyright (C) Research In Motion Limited 2010-2011. All rights reserved.
@@ skipping 1360 matching lines @@
 {
     if (m_titleElement != titleElement)
         return;
 
     m_titleElement = 0;
     m_titleSetExplicitly = false;
 
     // FIXME: This is broken for SVG.
     // Update title based on first title element in the head, if one exists.
     if (HTMLElement* headElement = head()) {
-        for (Element* element = headElement->firstElementChild(); element; element = element->nextElementSibling()) {
+        for (Element* element = ElementTraversal::firstWithin(*headElement); element; element = ElementTraversal::nextSibling(*element)) {
             if (!element->hasTagName(titleTag))
                 continue;
             HTMLTitleElement* title = toHTMLTitleElement(element);
             setTitleElement(title->text(), title);
             break;
         }
     }
 
     if (!m_titleElement)
         updateTitle(String());
@@ skipping 4069 matching lines @@
 void Document::defaultEventHandler(Event* event)
 {
     if (frame() && frame()->remotePlatformLayer()) {
         frame()->chromeClient().forwardInputEvent(this, event);
         return;
     }
     Node::defaultEventHandler(event);
 }
 
 } // namespace WebCore