Gracefully support Navigator Gamepad methods in a detached state.

Source/modules/gamepad/NavigatorGamepad.h

 /*
  * Copyright (C) 2011, 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:
  *
  * 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 44 matching lines @@
     static GamepadList* getGamepads(Navigator&);
 
     WebKitGamepadList* webkitGamepads();
     GamepadList* gamepads();
 
     virtual void trace(Visitor*);
 
     void didConnectOrDisconnectGamepad(unsigned index, const blink::WebGamepad&, bool connected);
 
 private:
-    explicit NavigatorGamepad(Document&);
+    explicit NavigatorGamepad(LocalFrame*);
 
     static const char* supplementName();
 
     // DOMWindowProperty
-    virtual void willDestroyGlobalObjectInFrame() OVERRIDE FINAL;
-    virtual void willDetachGlobalObjectFromFrame() OVERRIDE FINAL;
+    virtual void willDestroyGlobalObjectInFrame() OVERRIDE;
+    virtual void willDetachGlobalObjectFromFrame() OVERRIDE;
 
     // DeviceSensorEventController
-    virtual void registerWithDispatcher() OVERRIDE FINAL;
-    virtual void unregisterWithDispatcher() OVERRIDE FINAL;
-    virtual bool hasLastData() OVERRIDE FINAL;
-    virtual PassRefPtrWillBeRawPtr<Event> getLastEvent() OVERRIDE FINAL;
-    virtual bool isNullEvent(Event*) OVERRIDE FINAL;
+    virtual void registerWithDispatcher() OVERRIDE;
+    virtual void unregisterWithDispatcher() OVERRIDE;
+    virtual bool hasLastData() OVERRIDE;
+    virtual PassRefPtrWillBeRawPtr<Event> getLastEvent() OVERRIDE;
+    virtual bool isNullEvent(Event*) OVERRIDE;
+    virtual Document* document() OVERRIDE;
 
     // DOMWindowLifecycleObserver
-    virtual void didAddEventListener(DOMWindow*, const AtomicString&) OVERRIDE FINAL;
-    virtual void didRemoveEventListener(DOMWindow*, const AtomicString&) OVERRIDE FINAL;
-    virtual void didRemoveAllEventListeners(DOMWindow*) OVERRIDE FINAL;
+    virtual void didAddEventListener(DOMWindow*, const AtomicString&) OVERRIDE;
+    virtual void didRemoveEventListener(DOMWindow*, const AtomicString&) OVERRIDE;
+    virtual void didRemoveAllEventListeners(DOMWindow*) OVERRIDE;
 
     PersistentWillBeMember<GamepadList> m_gamepads;
     PersistentWillBeMember<WebKitGamepadList> m_webkitGamepads;
 };
 
 } // namespace WebCore
 
 #endif // NavigatorGamepad_h