Add support of vrdisplayconnect and vrdisplaydisconnect event

device/vr/vr_device.h

 // Copyright 2015 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_DEVICE_H
 #define DEVICE_VR_VR_DEVICE_H
 
 #include "base/macros.h"
+#include "device/vr/vr_client_dispatcher.h"
 #include "device/vr/vr_export.h"
 #include "device/vr/vr_service.mojom.h"
 
 namespace blink {
 struct WebHMDSensorState;
 }
 
 namespace ui {
 class BaseWindow;
 }
 
 namespace device {
 
 class VRDeviceProvider;
 
 const unsigned int VR_DEVICE_LAST_ID = 0xFFFFFFFF;
 
 class VRDevice {
  public:
   DEVICE_VR_EXPORT explicit VRDevice(VRDeviceProvider* provider);
   DEVICE_VR_EXPORT virtual ~VRDevice();
 
   DEVICE_VR_EXPORT VRDeviceProvider* provider() const { return provider_; }
+  DEVICE_VR_EXPORT VRClientDispatcher* client() const { return client_; }
   DEVICE_VR_EXPORT unsigned int id() const { return id_; }
 
   virtual VRDisplayPtr GetVRDevice() = 0;
   virtual VRPosePtr GetPose() = 0;
   virtual void ResetPose() = 0;
+  virtual void PollEvents() = 0;

[bajones, 2016/09/06 23:25:46]

As I'm looking through this code it occurs to me that we'll probably only be
firing events like this during PollEvents. For now lets pass the
VRClientDispatcher into this function rather than storing it as a member on the
VRDevice/VRDeviceProvider.

[shaobo.yan, 2016/09/07 02:45:50]

I'll move client_ from VRDevice to VRDeviceProvider to process
connect/disconnect signal.

+
+  void SetClient(VRClientDispatcher* client) { client_ = client; }
 
  private:
   VRDeviceProvider* provider_;
+  VRClientDispatcher* client_;
   unsigned int id_;
 
   static unsigned int next_id_;
 
   DISALLOW_COPY_AND_ASSIGN(VRDevice);
 };
 
 }  // namespace device
 
 #endif  // DEVICE_VR_VR_DEVICE_H