Add support of vrdisplayconnect and vrdisplaydisconnect event

device/vr/android/gvr/gvr_device.cc

 // 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.
 
 #include "device/vr/android/gvr/gvr_device.h"
 
 #include <math.h>
 #include <algorithm>
 
 #include "base/time/time.h"
 #include "base/trace_event/trace_event.h"
 #include "device/vr/android/gvr/gvr_delegate.h"
 #include "third_party/gvr-android-sdk/src/ndk-beta/include/vr/gvr/capi/include/gvr.h"
 #include "third_party/gvr-android-sdk/src/ndk-beta/include/vr/gvr/capi/include/gvr_types.h"
 #include "ui/gfx/transform.h"
 #include "ui/gfx/transform_util.h"
 
 namespace device {
 
 namespace {
 
 static const uint64_t kPredictionTimeWithoutVsyncNanos = 50000000;
 
 }  // namespace
 
 GvrDevice::GvrDevice(VRDeviceProvider* provider, GvrDelegate* delegate)
-    : VRDevice(provider), delegate_(delegate) {}
+    : VRDevice(provider),
+      delegate_(delegate),
+      isConnected_(false),
+      isConnectionStatusChanged_(false) {}
 
 GvrDevice::~GvrDevice() {}
 
 VRDisplayPtr GvrDevice::GetVRDevice() {
   TRACE_EVENT0("input", "GvrDevice::GetVRDevice");
 
   gvr::GvrApi* gvr_api = delegate_->gvr_api();
 
   VRDisplayPtr device = VRDisplay::New();
 
@@ skipping 118 matching lines @@
 void GvrDevice::UpdateLayerBounds(VRLayerBoundsPtr leftBounds,
                                   VRLayerBoundsPtr rightBounds) {
   delegate_->UpdateWebVRTextureBounds(0,  // Left eye
                                       leftBounds->left, leftBounds->top,
                                       leftBounds->width, leftBounds->height);
   delegate_->UpdateWebVRTextureBounds(1,  // Right eye
                                       rightBounds->left, rightBounds->top,
                                       rightBounds->width, rightBounds->height);
 }
 
+// It will poll status from device and resolve it.
+void GvrDevice::PollEvents(VRClientDispatcher* client) {
+  if (isConnectionStatusChanged_) {
+    client->OnDeviceConnectionStatusChanged(this, isConnected_);

[bajones, 2016/09/09 05:53:00]

Let's call this in UpdateConnectionStatus and avoid introducing the event
polling loop in this patch.

+    isConnectionStatusChanged_ = false;
+  }
+}
+
+void GvrDevice::UpdateConnectionStatus(bool isConnected) {
+  if (isConnected_ != isConnected) {
+    isConnected_ = isConnected;
+    isConnectionStatusChanged_ = true;
+  }
+}
+
 }  // namespace device