Clean up forward declarations in Source/modules

Source/modules/device_orientation/DeviceMotionDispatcher.h

 /*
  * Copyright (C) 2013 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:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 20 matching lines @@
 #ifndef DeviceMotionDispatcher_h
 #define DeviceMotionDispatcher_h
 
 #include "core/frame/PlatformEventDispatcher.h"
 #include "platform/heap/Handle.h"
 #include "public/platform/WebDeviceMotionListener.h"
 #include "wtf/RefPtr.h"
 
 namespace blink {
 
-class DeviceMotionController;
 class DeviceMotionData;
 class WebDeviceMotionData;
 
 // This class listens to device motion data and notifies all registered controllers.
 class DeviceMotionDispatcher final : public GarbageCollectedFinalized<DeviceMotionDispatcher>, public PlatformEventDispatcher, public WebDeviceMotionListener {
     USING_GARBAGE_COLLECTED_MIXIN(DeviceMotionDispatcher);
 public:
     static DeviceMotionDispatcher& instance();
     virtual ~DeviceMotionDispatcher();
 
@@ skipping 12 matching lines @@
     // Inherited from PlatformEventDispatcher.
     virtual void startListening() override;
     virtual void stopListening() override;
 
     Member<DeviceMotionData> m_lastDeviceMotionData;
 };
 
 } // namespace blink
 
 #endif // DeviceMotionDispatcher_h