device: Cleanup class/struct forward declarations

device/vr/android/gvr/gvr_device_provider.h

 // Copyright 2016 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 DEVICE_VR_ANDROID_GVR_DEVICE_PROVIDER_H
 #define DEVICE_VR_ANDROID_GVR_DEVICE_PROVIDER_H
 
 #include <memory>
 
 #include "base/macros.h"
 #include "base/memory/weak_ptr.h"
 #include "base/single_thread_task_runner.h"
 #include "device/vr/vr_device.h"
 #include "device/vr/vr_device_provider.h"
 #include "device/vr/vr_export.h"
 
 namespace device {
 
-class GvrDelegateProvider;
 class GvrDelegate;
 class GvrDevice;
-class VRServiceImpl;
 
 class DEVICE_VR_EXPORT GvrDeviceProvider : public VRDeviceProvider {
  public:
   GvrDeviceProvider();
   ~GvrDeviceProvider() override;
 
   void GetDevices(std::vector<VRDevice*>* devices) override;
   void Initialize() override;
 
   void SetListeningForActivate(bool listening) override;
@@ skipping 14 matching lines @@
   std::unique_ptr<GvrDevice> vr_device_;
 
   base::WeakPtrFactory<GvrDeviceProvider> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(GvrDeviceProvider);
 };
 
 }  // namespace device
 
 #endif  // DEVICE_VR_ANDROID_GVR_DEVICE_PROVIDER_H