Oilpan: disable conservative GCs during initial GC mixin construction.

Source/core/svg/SVGUseElement.h

 /*
  * Copyright (C) 2004, 2005, 2006, 2007, 2008 Nikolas Zimmermann <zimmermann@kde.org>
  * Copyright (C) 2004, 2005, 2006, 2007 Rob Buis <buis@kde.org>
  *
  * 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.
  *
  * This library is distributed in the hope that it will be useful,
@@ skipping 19 matching lines @@
 #include "platform/heap/Handle.h"
 
 namespace blink {
 
 class DocumentResource;
 
 class SVGUseElement final : public SVGGraphicsElement,
                             public SVGURIReference,
                             public DocumentResourceClient {
     DEFINE_WRAPPERTYPEINFO();
-    WILL_BE_USING_GARBAGE_COLLECTED_MIXIN(SVGUseElement);
+    WILL_BE_USING_GARBAGE_COLLECTED_MIXIN_NESTED(SVGUseElement, SVGGraphicsElement);
 public:
     static PassRefPtrWillBeRawPtr<SVGUseElement> create(Document&);
     virtual ~SVGUseElement();
 
     void invalidateShadowTree();
 
     LayoutObject* rendererClipChild() const;
 
     SVGAnimatedLength* x() const { return m_x.get(); }
     SVGAnimatedLength* y() const { return m_y.get(); }
@@ skipping 58 matching lines @@
     bool m_haveFiredLoadEvent;
     bool m_needsShadowTreeRecreation;
     RefPtrWillBeMember<SVGElement> m_targetElementInstance;
     ResourcePtr<DocumentResource> m_resource;
     Timer<SVGElement> m_svgLoadEventTimer;
 };
 
 } // namespace blink
 
 #endif // SVGUseElement_h