Oilpan: Remove guardRef and guardDeref from TreeScope.

Source/core/svg/SVGSVGElement.cpp

 /*
  * Copyright (C) 2004, 2005, 2006 Nikolas Zimmermann <zimmermann@kde.org>
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2010 Rob Buis <buis@kde.org>
  * Copyright (C) 2007 Apple Inc. All rights reserved.
  * Copyright (C) 2014 Google, Inc.
  *
  * 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
  * version 2 of the License, or (at your option) any later version.
@@ skipping 78 matching lines @@
 PassRefPtr<SVGSVGElement> SVGSVGElement::create(Document& document)
 {
     return adoptRef(new SVGSVGElement(document));
 }
 
 SVGSVGElement::~SVGSVGElement()
 {
     if (m_viewSpec)
         m_viewSpec->detachContextElement();
 
+#if !ENABLE(OILPAN)
     // There are cases where removedFromDocument() is not called.
     // see ContainerNode::removeAllChildren, called by its destructor.
+    // With Oilpan, either removedFrom is called or the document
+    // is dead as well and there is no reason to clear the extensions.
     document().accessSVGExtensions().removeTimeContainer(this);
 
     ASSERT(inDocument() || !accessDocumentSVGExtensions().isSVGRootWithRelativeLengthDescendents(this));
+#endif
 }
 
 PassRefPtr<SVGRectTearOff> SVGSVGElement::viewport() const
 {
     // FIXME: This method doesn't follow the spec and is basically untested. Parent documents are not considered here.
     // As we have no test coverage for this, we're going to disable it completly for now.
     return SVGRectTearOff::create(SVGRect::create(), 0, PropertyIsNotAnimVal);
 }
 
 float SVGSVGElement::pixelUnitToMillimeterX() const
@@ skipping 666 matching lines @@
     // Fall back to traversing our subtree. Duplicate ids are allowed, the first found will
     // be returned.
     for (Element* element = ElementTraversal::firstWithin(*this); element; element = ElementTraversal::next(*element, this)) {
         if (element->getIdAttribute() == id)
             return element;
     }
     return 0;
 }
 
 }