Introduce NavigatorID IDL interface

Source/core/page/WorkerNavigator.h

 /*
  * Copyright (C) 2008 Apple 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:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 22 matching lines @@
 #include "wtf/RefCounted.h"
 #include "wtf/text/WTFString.h"
 
 namespace WebCore {
 
 class WorkerNavigator : public RefCounted<WorkerNavigator>, public ScriptWrappable, public NavigatorBase, public Supplementable<WorkerNavigator> {
 public:
     static PassRefPtr<WorkerNavigator> create(const String& userAgent) { return adoptRef(new WorkerNavigator(userAgent)); }
     virtual ~WorkerNavigator();
 
-    virtual String userAgent() const;
+    virtual String userAgent() const OVERRIDE;
 
 private:
     explicit WorkerNavigator(const String&);
 
     String m_userAgent;
 };
 
 } // namespace WebCore
 
 #endif // WorkerNavigator_h