Reland of mojo VR interface simpified.

device/vr/vr_client_dispatcher.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_CLIENT_DISPATCHER_H
-#define DEVICE_VR_VR_CLIENT_DISPATCHER_H
-
-#include "device/vr/vr_service.mojom.h"
-
-namespace device {
-
-class VRDevice;
-
-class VRClientDispatcher {
- public:
-  virtual void OnDeviceChanged(VRDisplayPtr device) = 0;
-  virtual void OnDeviceConnectionStatusChanged(VRDevice* device,
-                                               bool is_connected) = 0;
-  virtual void OnPresentEnded(VRDevice* device) = 0;
-};
-
-}  // namespace device
-
-#endif  // DEVICE_VR_VR_CLIENT_DISPATCHER_H