Add support of vrdisplayconnect and vrdisplaydisconnect event

device/vr/android/gvr/gvr_device_provider.cc

Index: device/vr/android/gvr/gvr_device_provider.cc
diff --git a/device/vr/android/gvr/gvr_device_provider.cc b/device/vr/android/gvr/gvr_device_provider.cc
index ad21151426db9f44117c538c14586b8f061e47e8..6e7fd89762620e64102f44778e3079da12ec9548 100644
--- a/device/vr/android/gvr/gvr_device_provider.cc
+++ b/device/vr/android/gvr/gvr_device_provider.cc
@@ -85,22 +85,33 @@ void GvrDeviceProvider::GetDevices(std::vector<VRDevice*>* devices) {
     devices->push_back(vr_device_.get());
 }
 
+void GvrDeviceProvider::SetClient(VRClientDispatcher* client) {
+  if (!client_)
+    client_.reset(client);
+}
+
 void GvrDeviceProvider::Initialize() {
-  if (!delegate_) {
+  if (!delegate_)
     delegate_.reset(new GvrDeviceProviderDelegate());
-  }
 }
 
 void GvrDeviceProvider::OnDelegateInitialized(GvrDelegate* delegate) {
   if (!vr_device_)
     vr_device_.reset(new GvrDevice(this, delegate));
 
-  // Should fire a vrdisplayconnected event here.
+  client_->OnDeviceConnectionStatusChanged(vr_device_.get(), true);
 }
 
 void GvrDeviceProvider::OnDelegateShutdown() {
   // Nothing to do here just yet. Eventually want to shut down the VRDevice and
   // fire a vrdisplaydisconnected event.

[bajones, 2016/09/12 01:36:15]

Happily this comment is no longer accurate! Lets remove it.

[shaobo.yan, 2016/09/12 01:59:01]

Done.

+  if (client_ && vr_device_)
+    client_->OnDeviceConnectionStatusChanged(vr_device_.get(), false);
+}
+
+void GvrDeviceProvider::PollEvents() {
+  if (vr_device_)
+    vr_device_->PollEvents();
 }
 
 }  // namespace device