Add support of vrdisplayconnect and vrdisplaydisconnect event

third_party/WebKit/Source/modules/vr/VRDisplay.cpp

 // 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 "modules/vr/VRDisplay.h"
 
 #include "core/dom/DOMException.h"
 #include "core/dom/Fullscreen.h"
 #include "core/inspector/ConsoleMessage.h"
 #include "modules/vr/NavigatorVR.h"
@@ skipping 61 matching lines @@
 
     if (!display->stageParameters.is_null()) {
         if (!m_stageParameters)
             m_stageParameters = new VRStageParameters();
         m_stageParameters->update(display->stageParameters);
     } else {
         m_stageParameters = nullptr;
     }
 }
 
+void VRDisplay::disconnected()
+{
+    if (m_isConnected)
+        m_isConnected = !m_isConnected;
+}
+
 VRPose* VRDisplay::getPose()
 {
     if (m_canUpdateFramePose) {
         m_framePose = getImmediatePose();
         Platform::current()->currentThread()->addTaskObserver(this);
         m_canUpdateFramePose = false;
     }
 
     return m_framePose;
 }
@@ skipping 210 matching lines @@
     visitor->trace(m_navigatorVR);
     visitor->trace(m_capabilities);
     visitor->trace(m_stageParameters);
     visitor->trace(m_eyeParametersLeft);
     visitor->trace(m_eyeParametersRight);
     visitor->trace(m_framePose);
     visitor->trace(m_layer);
 }
 
 } // namespace blink