Remove more oilpan.

sky/engine/core/css/resolver/MatchedPropertiesCache.h

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  * Copyright (C) 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011 Apple Inc. All rights reserved.
  * Copyright (C) 2013 Google 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.
  *
@@ skipping 18 matching lines @@
 #include "platform/heap/Handle.h"
 #include "wtf/Forward.h"
 #include "wtf/HashMap.h"
 #include "wtf/Noncopyable.h"
 
 namespace blink {
 
 class RenderStyle;
 class StyleResolverState;
 
-class CachedMatchedProperties final : public DummyBase<CachedMatchedProperties> {
+class CachedMatchedProperties final {
 
 public:
     Vector<MatchedProperties> matchedProperties;
     MatchRanges ranges;
     RefPtr<RenderStyle> renderStyle;
     RefPtr<RenderStyle> parentRenderStyle;
 
     void set(const RenderStyle*, const RenderStyle* parentStyle, const MatchResult&);
     void clear();
     void trace(Visitor* visitor) { visitor->trace(matchedProperties); }
@@ skipping 23 matching lines @@
     unsigned m_additionsSinceLastSweep;
 
     typedef HashMap<unsigned, OwnPtr<CachedMatchedProperties> > Cache;
     Timer<MatchedPropertiesCache> m_sweepTimer;
     Cache m_cache;
 };
 
 }
 
 #endif