[oilpan] Implement accept methods to trace the class hierarchy of SVGElement and all sub-classes.

Source/core/svg/SVGGlyphRefElement.h

 /*
  * Copyright (C) 2011 Leo Yang <leoyang@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 28 matching lines @@
     void setGlyphRef(const AtomicString&, ExceptionCode&);
     float x() const { return m_x; }
     void setX(float, ExceptionCode&);
     float y() const { return m_y; }
     void setY(float, ExceptionCode&);
     float dx() const { return m_dx; }
     void setDx(float, ExceptionCode&);
     float dy() const { return m_dy; }
     void setDy(float, ExceptionCode&);
 
+    virtual void accept(Visitor* visitor) const OVERRIDE { SVGStyledElement::accept(visitor); }
+
 private:
     SVGGlyphRefElement(const QualifiedName&, const Handle<Document>&);
 
     virtual bool rendererIsNeeded(const NodeRenderingContext&) { return false; }
 
     BEGIN_DECLARE_ANIMATED_PROPERTIES(SVGGlyphRefElement)
         DECLARE_ANIMATED_STRING(Href, href)
     END_DECLARE_ANIMATED_PROPERTIES
 
     float m_x;
     float m_y;
     float m_dx;
     float m_dy;
 };
 
 }
 
 #endif
 #endif