Implement cloneNode for Document

Source/core/svg/SVGDocument.cpp

 /*
  * Copyright (C) 2004, 2005 Nikolas Zimmermann <zimmermann@kde.org>
  * Copyright (C) 2004, 2005, 2006, 2007 Rob Buis <buis@kde.org>
  *
  * 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.
  *
  * This library is distributed in the hope that it will be useful,
@@ skipping 76 matching lines @@
 
 void SVGDocument::updatePan(const FloatPoint& pos) const
 {
     if (rootElement()) {
         rootElement()->setCurrentTranslate(FloatPoint(pos.x() - m_translate.x(), pos.y() - m_translate.y()));
         if (renderer())
             renderer()->repaint();
     }
 }
 
+PassRefPtr<Document> SVGDocument::cloneDocumentWithoutChildren()
+{
+    return create(DocumentInit(url()));
+}
+
 bool SVGDocument::childShouldCreateRenderer(const NodeRenderingContext& childContext) const
 {
     if (childContext.node()->hasTagName(SVGNames::svgTag))
         return toSVGSVGElement(childContext.node())->isValid();
     return true;
 }
 
 }