Oilpan: Ensure that classes with virtual trace methods always have vtables for their left-most base…

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 737 matching lines @@
 
     m_resource = resource;
     if (m_resource)
         m_resource->addClient(this);
 }
 
 void SVGUseElement::trace(Visitor* visitor)
 {
     visitor->trace(m_targetElementInstance);
     SVGGraphicsElement::trace(visitor);
+    DocumentResourceClient::trace(visitor);
 }
 
 }