Refine VRDevice Class

device/vr/vr_display_impl.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_VR_DISPLAY_IMPL_H
 #define DEVICE_VR_VR_DISPLAY_IMPL_H
 
 #include <memory>
 
 #include "base/macros.h"
 #include "base/memory/weak_ptr.h"
 #include "device/vr/vr_device.h"
 #include "device/vr/vr_export.h"
 #include "device/vr/vr_service.mojom.h"
 #include "mojo/public/cpp/bindings/binding.h"
 
 namespace device {
 
+class VRServiceImpl;
+
 class VRDisplayImpl : public mojom::VRDisplay {
  public:
   VRDisplayImpl(device::VRDevice* device, VRServiceImpl* service);
   ~VRDisplayImpl() override;
 
   mojom::VRDisplayClient* client() { return client_.get(); }
 
  private:
   friend class VRDisplayImplTest;
   friend class VRServiceImpl;
@@ skipping 17 matching lines @@
   mojom::VRDisplayClientPtr client_;
   device::VRDevice* device_;
   VRServiceImpl* service_;
 
   base::WeakPtrFactory<VRDisplayImpl> weak_ptr_factory_;
 };
 
 }  // namespace device
 
 #endif  //  DEVICE_VR_VR_DISPLAY_IMPL_H