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

Source/core/svg/SVGFEFuncBElement.h

Index: Source/core/svg/SVGFEFuncBElement.h
diff --git a/Source/core/svg/SVGFEFuncBElement.h b/Source/core/svg/SVGFEFuncBElement.h
index 2d14fc101de4b284c7739c113fe7ea3cc80e2b5c..08b3a59d1b932104b66be53ec6c743917728d499 100644
--- a/Source/core/svg/SVGFEFuncBElement.h
+++ b/Source/core/svg/SVGFEFuncBElement.h
@@ -30,6 +30,8 @@ class SVGFEFuncBElement : public SVGComponentTransferFunctionElement {
 public:
     static PassRefPtr<SVGFEFuncBElement> create(const QualifiedName&, const Handle<Document>&);
 
+    virtual void accept(Visitor* visitor) const OVERRIDE { SVGComponentTransferFunctionElement::accept(visitor); }
+
 private:
     SVGFEFuncBElement(const QualifiedName&, const Handle<Document>&);
 };