Remove more oilpan.

sky/engine/core/dom/shadow/ShadowRootRareData.h

 /*
  * Copyright (C) 2013 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 19 matching lines @@
 
 #ifndef ShadowRootRareData_h
 #define ShadowRootRareData_h
 
 #include "core/dom/shadow/InsertionPoint.h"
 #include "wtf/RefPtr.h"
 #include "wtf/Vector.h"
 
 namespace blink {
 
-class ShadowRootRareData : public DummyBase<ShadowRootRareData> {
+class ShadowRootRareData {
 public:
     ShadowRootRareData()
         : m_descendantShadowElementCount(0)
         , m_descendantContentElementCount(0)
         , m_childShadowRootCount(0)
     {
     }
 
     HTMLShadowElement* shadowInsertionPointOfYoungerShadowRoot() const { return m_shadowInsertionPointOfYoungerShadowRoot.get(); }
     void setShadowInsertionPointOfYoungerShadowRoot(PassRefPtr<HTMLShadowElement> shadowInsertionPoint) { m_shadowInsertionPointOfYoungerShadowRoot = shadowInsertionPoint; }
@@ skipping 56 matching lines @@
     else
         ASSERT_NOT_REACHED();
 
     ASSERT(m_descendantContentElementCount >= 0);
     ASSERT(m_descendantShadowElementCount >= 0);
 }
 
 } // namespace blink
 
 #endif