Remove more oilpan.

sky/engine/core/animation/AnimationTimeline.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 32 matching lines @@
 
 namespace blink {
 
 class Document;
 class AnimationNode;
 
 // AnimationTimeline is constructed and owned by Document, and tied to its lifecycle.
 class AnimationTimeline : public RefCounted<AnimationTimeline>, public ScriptWrappable {
     DEFINE_WRAPPERTYPEINFO();
 public:
-    class PlatformTiming : public DummyBase<PlatformTiming> {
+    class PlatformTiming {
 
     public:
         // Calls AnimationTimeline's wake() method after duration seconds.
         virtual void wakeAfter(double duration) = 0;
         virtual void cancelWake() = 0;
         virtual void serviceOnNextFrame() = 0;
         virtual ~PlatformTiming() { }
         virtual void trace(Visitor*) { }
     };
 
@@ skipping 71 matching lines @@
         RawPtr<AnimationTimeline> m_timeline;
         Timer<AnimationTimelineTiming> m_timer;
     };
 
     friend class AnimationAnimationTimelineTest;
 };
 
 } // namespace blink
 
 #endif