Add support for DOM4's XMLDocument interface

Source/core/svg/SVGUseElement.cpp

 /*
  * Copyright (C) 2004, 2005, 2006, 2007, 2008 Nikolas Zimmermann <zimmermann@kde.org>
  * Copyright (C) 2004, 2005, 2006, 2007 Rob Buis <buis@kde.org>
  * Copyright (C) Research In Motion Limited 2009-2010. All rights reserved.
  * Copyright (C) 2011 Torch Mobile (Beijing) Co. Ltd. All rights reserved.
  * Copyright (C) 2012 University of Szeged
  * Copyright (C) 2012 Renata Hodovan <reni@webkit.org>
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
@@ skipping 132 matching lines @@
     else if (SVGURIReference::parseAttribute(name, value)) {
     } else
         ASSERT_NOT_REACHED();
 
     reportAttributeParsingError(parseError, name, value);
 }
 
 #if !ASSERT_DISABLED
 static inline bool isWellFormedDocument(Document* document)
 {
-    if (document->isSVGDocument() || document->isXHTMLDocument())
+    if (document->isXMLDocument())
         return static_cast<XMLDocumentParser*>(document->parser())->wellFormed();
     return true;
 }
 #endif
 
 Node::InsertionNotificationRequest SVGUseElement::insertedInto(ContainerNode* rootParent)
 {
     // This functions exists to assure assumptions made in the code regarding SVGElementInstance creation/destruction are satisfied.
     SVGGraphicsElement::insertedInto(rootParent);
     if (!rootParent->inDocument())
@@ skipping 817 matching lines @@
 
     if (m_resource)
         m_resource->removeClient(this);
 
     m_resource = resource;
     if (m_resource)
         m_resource->addClient(this);
 }
 
 }