[cleanup, battery] Don't include unneeded headers.

third_party/WebKit/Source/modules/battery/NavigatorBattery.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 NavigatorBattery_h
 #define NavigatorBattery_h
 
-#include "bindings/core/v8/ScriptPromise.h"
-#include "core/frame/Navigator.h"
 #include "platform/Supplementable.h"
 #include "platform/heap/Handle.h"
 
 namespace blink {
 
 class BatteryManager;
 class Navigator;
+class ScriptPromise;
+class ScriptState;
 
 class NavigatorBattery final : public GarbageCollected<NavigatorBattery>,
                                public Supplement<Navigator> {
   USING_GARBAGE_COLLECTED_MIXIN(NavigatorBattery);
 
  public:
   static NavigatorBattery& From(Navigator&);
 
   static ScriptPromise getBattery(ScriptState*, Navigator&);
   ScriptPromise getBattery(ScriptState*);
 
   DECLARE_TRACE();
 
  private:
   explicit NavigatorBattery(Navigator&);
   static const char* SupplementName();
 
   Member<BatteryManager> battery_manager_;
 };
 
 }  // namespace blink
 
 #endif  // NavigatorBattery_h