Remove tons of OILPAN.

sky/engine/core/html/imports/HTMLImport.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 101 matching lines @@
     const HTMLImportState& state() const { return m_state; }
 
     void appendImport(HTMLImport*);
 
     virtual Document* document() const = 0;
     virtual bool isDone() const = 0; // FIXME: Should be renamed to haveFinishedLoading()
     virtual HTMLImportLoader* loader() const { return 0; }
     virtual void stateWillChange() { }
     virtual void stateDidChange();
 
-    virtual void trace(Visitor*) { }
-
 protected:
     // Stating from most conservative state.
     // It will be corrected through state update flow.
     explicit HTMLImport(SyncMode sync)
         : m_sync(sync)
     { }
 
     static void recalcTreeState(HTMLImport* root);
 
 #if !defined(NDEBUG)
     void show();
     void showTree(HTMLImport* highlight, unsigned depth);
     virtual void showThis();
 #endif
 
 private:
     HTMLImportState m_state;
     unsigned m_sync : 1;
 };
 
 } // namespace blink
 
 #endif // HTMLImport_h