SVG object with same idrefs get conflicted even they are under different shadow root

third_party/WebKit/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 310 matching lines @@
     AtomicString id;
     Element* target = targetElementFromIRIString(hrefString(), treeScope(), &id, externalDocument);
     if (!target || !target->inShadowIncludingDocument()) {
         // If we can't find the target of an external element, just give up.
         // We can't observe if the target somewhen enters the external document, nor should we do it.
         if (externalDocument)
             return;
         if (id.isEmpty())
             return;
 
-        document().accessSVGExtensions().addPendingResource(id, this);
+        treeScope().accessSVGTreeScopedResources().addPendingResource(id, this);
         ASSERT(hasPendingResources());
         return;
     }
 
     if (target->isSVGElement()) {
         buildShadowAndInstanceTree(toSVGElement(*target));
         invalidateDependentShadowTrees();
     }
 
     ASSERT(!m_needsShadowTreeRecreation);
@@ skipping 407 matching lines @@
 
     if (m_resource)
         m_resource->removeClient(this);
 
     m_resource = resource;
     if (m_resource)
         m_resource->addClient(this);
 }
 
 } // namespace blink