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

Source/core/svg/SVGAltGlyphElement.h

 /*
  * Copyright (C) 2004, 2005, 2008 Nikolas Zimmermann <zimmermann@kde.org>
  * Copyright (C) 2004, 2005, 2006 Rob Buis <buis@kde.org>
  * Copyright (C) 2008 Apple Inc. All rights reserved.
  *
  * 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 26 matching lines @@
 public:
     static PassRefPtr<SVGAltGlyphElement> create(const QualifiedName&, const Handle<Document>&);
 
     const AtomicString& glyphRef() const;
     void setGlyphRef(const AtomicString&, ExceptionCode&);
     const AtomicString& format() const;
     void setFormat(const AtomicString&, ExceptionCode&);
 
     bool hasValidGlyphElements(Vector<String>& glyphNames) const;
 
+    virtual void accept(Visitor* visitor) const OVERRIDE { SVGTextPositioningElement::accept(visitor); }
+
 private:
     SVGAltGlyphElement(const QualifiedName&, const Handle<Document>&);
 
     virtual RenderObject* createRenderer(RenderArena*, RenderStyle*);
     virtual bool childShouldCreateRenderer(const NodeRenderingContext&) const;
 
     BEGIN_DECLARE_ANIMATED_PROPERTIES(SVGAltGlyphElement)
         DECLARE_ANIMATED_STRING(Href, href)
     END_DECLARE_ANIMATED_PROPERTIES
 };
 
 } // namespace WebCore
 
 #endif // ENABLE(SVG)
 #endif