Implement cloneNode for Document

Source/core/html/HTMLDocument.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  * Copyright (C) 2003, 2004, 2005, 2006, 2007, 2008 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 198 matching lines @@
 {
     if (HTMLBodyElement* bodyElement = bodyAsHTMLBodyElement()) {
         // This check is a bit silly, but some benchmarks like to set the
         // document's link colors over and over to the same value and we
         // don't want to incur a style update each time.
         if (bodyElement->vLink() != value)
             bodyElement->setVLink(value);
     }
 }
 
+PassRefPtr<Document> HTMLDocument::cloneDocumentWithoutChildren()
+{
+    return create(DocumentInit(url()).withRegistrationContext(registrationContext()));
+}
+
 // --------------------------------------------------------------------------
 // not part of the DOM
 // --------------------------------------------------------------------------
 
 void HTMLDocument::addItemToMap(HashCountedSet<StringImpl*>& map, const AtomicString& name)
 {
     if (name.isEmpty())
         return;
     map.add(name.impl());
     if (Frame* f = frame())
@@ skipping 97 matching lines @@
 }
 
 void HTMLDocument::clear()
 {
     // FIXME: This does nothing, and that seems unlikely to be correct.
     // We've long had a comment saying that IE doesn't support this.
     // But I do see it in the documentation for Mozilla.
 }
 
 }