Add Element::subResourceAttributeName() virtual function

Source/core/html/HTMLEmbedElement.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2000 Stefan Schimanski (1Stein@gmx.de)
  * Copyright (C) 2004, 2005, 2006, 2008, 2009, 2011 Apple Inc. All rights reserved.
  * Copyright (C) 2008 Nokia Corporation and/or its subsidiary(-ies)
  *
  * 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
@@ skipping 172 matching lines @@
         }
     }
     return HTMLPlugInElement::rendererIsNeeded(style);
 }
 
 bool HTMLEmbedElement::isURLAttribute(const Attribute& attribute) const
 {
     return attribute.name() == srcAttr || HTMLPlugInElement::isURLAttribute(attribute);
 }
 
+const QualifiedName& HTMLEmbedElement::subResourceAttributeName() const
+{
+    return srcAttr;
+}
+
 const AtomicString HTMLEmbedElement::imageSourceURL() const
 {
     return getAttribute(srcAttr);
 }
 
 bool HTMLEmbedElement::isInteractiveContent() const
 {
     return true;
 }
 
 bool HTMLEmbedElement::isExposed() const
 {
     // http://www.whatwg.org/specs/web-apps/current-work/#exposed
     for (Node* ancestor = parentNode(); ancestor; ancestor = ancestor->parentNode()) {
         if (isHTMLObjectElement(*ancestor) && toHTMLObjectElement(*ancestor).isExposed())
             return false;
     }
     return true;
 }
 
 }