Remove tons of OILPAN.

sky/engine/core/dom/DOMURL.h

 /*
  * Copyright (C) 2011 Google Inc. All rights reserved.
  * Copyright (C) 2012 Motorola Mobility Inc.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  *
  * 1.  Redistributions of source code must retain the above copyright
  *     notice, this list of conditions and the following disclaimer.
@@ skipping 45 matching lines @@
         ASSERT(base);
         return adoptRef(new DOMURL(url, base->m_url, exceptionState));
     }
 
     virtual KURL url() const override { return m_url; }
     virtual void setURL(const KURL& url) override { m_url = url; }
 
     virtual String input() const override { return m_input; }
     virtual void setInput(const String&) override;
 
-    void trace(Visitor*) { }
-
 private:
     DOMURL(const String& url, const KURL& base, ExceptionState&);
 
     KURL m_url;
     String m_input;
 };
 
 } // namespace blink
 
 #endif // DOMURL_h