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

Source/core/html/shadow/InsertionPoint.cpp

 /*
  * Copyright (C) 2012 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.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 235 matching lines @@
             if (InsertionPoint* insertedTo = parent->isShadowRoot() ? ScopeContentDistribution::assignedTo(toShadowRoot(parent)) : 0) {
                 current = insertedTo;
                 results.append(insertedTo);
                 continue;
             }
         }
         return;
     }
 }
 
+void InsertionPoint::acceptHeapVisitor(Visitor* visitor) const
+{
+    HTMLElement::acceptHeapVisitor(visitor);
+}
+
 } // namespace WebCore