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

Source/core/html/shadow/HTMLContentElement.cpp

 /*
  * Copyright (C) 2011 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Neither the name of Google Inc. nor the names of its
@@ skipping 180 matching lines @@
     for (const CSSSelector* selector = m_selectorList.first(); selector; selector = m_selectorList.next(selector)) {
         if (!validateSelector(selector))
             return false;
     }
 
     return true;
 }
 
 void HTMLContentElement::acceptHeapVisitor(Visitor* visitor) const
 {
-    HTMLElement::acceptHeapVisitor(visitor);
+    InsertionPoint::acceptHeapVisitor(visitor);
 }
 
 }