[oilpan] The Node hierarchy should have correct accept method chains

Source/core/dom/Notation.cpp

 /*
  * Copyright (C) 2000 Peter Kelly (pmk@post.com)
  * Copyright (C) 2006, 2009 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.
  *
  * This library is distributed in the hope that it will be useful,
@@ skipping 37 matching lines @@
 {
     // Spec says cloning Notation nodes is "implementation dependent". We do not support it.
     return 0;
 }
 
 bool Notation::childTypeAllowed(NodeType) const
 {
     return false;
 }
 
+void Notation::acceptHeapVisitor(Visitor* visitor) const
+{
+    ContainerNode::acceptHeapVisitor(visitor);
+}
+
 } // namespace