Include wtf/RefCounted.h less often in modules/

Source/modules/gamepad/WebKitGamepadList.h

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef WebKitGamepadList_h
 #define WebKitGamepadList_h
 
 #include "bindings/v8/ScriptWrappable.h"
 #include "modules/gamepad/WebKitGamepad.h"
 #include "platform/heap/Handle.h"
 #include "public/platform/WebGamepads.h"
-#include "wtf/RefCounted.h"
 #include "wtf/Vector.h"
 
 namespace WebCore {
 
 class WebKitGamepadList FINAL : public GarbageCollectedFinalized<WebKitGamepadList>, public ScriptWrappable {
 public:
     static WebKitGamepadList* create()
     {
         return new WebKitGamepadList;
     }
     ~WebKitGamepadList();
 
     void set(unsigned index, WebKitGamepad*);
     WebKitGamepad* item(unsigned index);
     unsigned length() const { return blink::WebGamepads::itemsLengthCap; }
 
     void trace(Visitor*);
 
 private:
     WebKitGamepadList();
     Member<WebKitGamepad> m_items[blink::WebGamepads::itemsLengthCap];
 };
 
 } // namespace WebCore
 
 #endif // WebKitGamepadList_h