Oilpan: move SVG property hierarchy to the heap.

Source/core/svg/SVGMPathElement.h

 /*
  * Copyright (C) 2007 Eric Seidel <eric@webkit.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 15 matching lines @@
 #include "core/svg/SVGElement.h"
 #include "core/svg/SVGURIReference.h"
 
 namespace blink {
 
 class SVGPathElement;
 
 class SVGMPathElement final : public SVGElement,
                               public SVGURIReference {
     DEFINE_WRAPPERTYPEINFO();
+    WILL_BE_USING_GARBAGE_COLLECTED_MIXIN(SVGMPathElement);
 public:
     DECLARE_NODE_FACTORY(SVGMPathElement);
 
     virtual ~SVGMPathElement();
 
     SVGPathElement* pathElement();
 
     void targetPathChanged();
 
+    virtual void trace(Visitor*) override;
+
 private:
     explicit SVGMPathElement(Document&);
 
     virtual void buildPendingResource() override;
     void clearResourceReferences();
     virtual InsertionNotificationRequest insertedInto(ContainerNode*) override;
     virtual void removedFrom(ContainerNode*) override;
 
     virtual void parseAttribute(const QualifiedName&, const AtomicString&) override;
     virtual void svgAttributeChanged(const QualifiedName&) override;
 
     virtual bool rendererIsNeeded(const RenderStyle&) override { return false; }
     void notifyParentOfPathChange(ContainerNode*);
 
 };
 
 } // namespace blink
 
 #endif // SVGMPathElement_h