Oilpan: disable conservative GCs during initial GC mixin construction.

Source/core/svg/SVGTextPathElement.h

 /*
  * Copyright (C) 2007 Nikolas Zimmermann <zimmermann@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,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
@@ skipping 27 matching lines @@
     SVGTextPathSpacingAuto,
     SVGTextPathSpacingExact
 };
 
 template<> const SVGEnumerationStringEntries& getStaticStringEntries<SVGTextPathMethodType>();
 template<> const SVGEnumerationStringEntries& getStaticStringEntries<SVGTextPathSpacingType>();
 
 class SVGTextPathElement final : public SVGTextContentElement,
                                  public SVGURIReference {
     DEFINE_WRAPPERTYPEINFO();
-    WILL_BE_USING_GARBAGE_COLLECTED_MIXIN(SVGTextPathElement);
+    WILL_BE_USING_GARBAGE_COLLECTED_MIXIN_NESTED(SVGTextPathElement, SVGGraphicsElement);
 public:
     // Forward declare enumerations in the W3C naming scheme, for IDL generation.
     enum {
         TEXTPATH_METHODTYPE_UNKNOWN = SVGTextPathMethodUnknown,
         TEXTPATH_METHODTYPE_ALIGN = SVGTextPathMethodAlign,
         TEXTPATH_METHODTYPE_STRETCH = SVGTextPathMethodStretch,
         TEXTPATH_SPACINGTYPE_UNKNOWN = SVGTextPathSpacingUnknown,
         TEXTPATH_SPACINGTYPE_AUTO = SVGTextPathSpacingAuto,
         TEXTPATH_SPACINGTYPE_EXACT = SVGTextPathSpacingExact
     };
@@ skipping 26 matching lines @@
     virtual bool selfHasRelativeLengths() const override;
 
     RefPtrWillBeMember<SVGAnimatedLength> m_startOffset;
     RefPtrWillBeMember<SVGAnimatedEnumeration<SVGTextPathMethodType>> m_method;
     RefPtrWillBeMember<SVGAnimatedEnumeration<SVGTextPathSpacingType>> m_spacing;
 };
 
 } // namespace blink
 
 #endif // SVGTextPathElement_h