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

Source/core/svg/SVGLinearGradientElement.h

 /*
  * Copyright (C) 2004, 2005, 2006, 2008 Nikolas Zimmermann <zimmermann@kde.org>
  * Copyright (C) 2004, 2005, 2006 Rob Buis <buis@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,
@@ skipping 18 matching lines @@
 
 struct LinearGradientAttributes;
 
 class SVGLinearGradientElement : public SVGGradientElement {
     DEFINE_SELF_HANDLE(SVGLinearGradientElement)
 public:
     static PassRefPtr<SVGLinearGradientElement> create(const QualifiedName&, const Handle<Document>&);
 
     bool collectGradientAttributes(LinearGradientAttributes&);
 
+    virtual void accept(Visitor* visitor) const OVERRIDE { SVGGradientElement::accept(visitor); }
+
 private:
     SVGLinearGradientElement(const QualifiedName&, const Handle<Document>&);
 
     bool isSupportedAttribute(const QualifiedName&);
     virtual void parseAttribute(const QualifiedName&, const AtomicString&) OVERRIDE;
     virtual void svgAttributeChanged(const QualifiedName&);
 
     virtual RenderObject* createRenderer(RenderArena*, RenderStyle*);
 
     virtual bool selfHasRelativeLengths() const;
 
     BEGIN_DECLARE_ANIMATED_PROPERTIES(SVGLinearGradientElement)
         DECLARE_ANIMATED_LENGTH(X1, x1)
         DECLARE_ANIMATED_LENGTH(Y1, y1)
         DECLARE_ANIMATED_LENGTH(X2, x2)
         DECLARE_ANIMATED_LENGTH(Y2, y2)
     END_DECLARE_ANIMATED_PROPERTIES
 };
 
 } // namespace WebCore
 
 #endif // ENABLE(SVG)
 #endif