Do not show display:none clipPath targets when referenced with <use>

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 475 matching lines @@
         || isSVGPolylineElement(element)
         || isSVGTextElement(element);
 }
 
 void SVGUseElement::toClipPath(Path& path) const
 {
     ASSERT(path.isEmpty());
 
     const SVGGraphicsElement* element = targetGraphicsElementForClipping();
 
-    if (!element)
+    if (!element || !element->layoutObject())
         return;
 
     if (element->isSVGGeometryElement()) {
         toSVGGeometryElement(*element).toClipPath(path);
         // FIXME: Avoid manual resolution of x/y here. Its potentially harmful.
         SVGLengthContext lengthContext(this);
         path.translate(FloatSize(m_x->currentValue()->value(lengthContext), m_y->currentValue()->value(lengthContext)));
         path.transform(calculateAnimatedLocalTransform());
     }
 }
@@ skipping 244 matching lines @@
 
     if (m_resource)
         m_resource->removeClient(this);
 
     m_resource = resource;
     if (m_resource)
         m_resource->addClient(this);
 }
 
 } // namespace blink