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

Source/core/svg/SVGHKernElement.h

 /*
  * Copyright (C) 2007 Eric Seidel <eric@webkit.org>
  * Copyright (C) 2007 Nikolas Zimmermann <zimmermann@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 15 matching lines @@
 #include "core/svg/SVGFontElement.h"
 
 namespace WebCore {
 
 class SVGHKernElement : public SVGElement {
 public:
     static PassRefPtr<SVGHKernElement> create(const QualifiedName&, const Handle<Document>&);
 
     void buildHorizontalKerningPair(KerningPairVector&);
 
+    virtual void accept(Visitor* visitor) const OVERRIDE { SVGElement::accept(visitor); }
+
 private:
     SVGHKernElement(const QualifiedName&, const Handle<Document>&);
 
     virtual InsertionNotificationRequest insertedInto(const Handle<ContainerNode>&) OVERRIDE;
     virtual void removedFrom(const Handle<ContainerNode>&) OVERRIDE;
 
     virtual bool rendererIsNeeded(const NodeRenderingContext&) { return false; }
 };
 
 } // namespace WebCore
 
 #endif // ENABLE(SVG_FONTS)
 #endif