Add support of vrdisplayconnect and vrdisplaydisconnect event

third_party/WebKit/Source/modules/vr/VRDisplay.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 VRDisplay_h
 #define VRDisplay_h
 
 #include "bindings/core/v8/ScriptWrappable.h"
 #include "core/dom/Document.h"
 #include "core/dom/FrameRequestCallback.h"
@@ skipping 73 matching lines @@
     VRDisplay(NavigatorVR*);
 
     void update(const device::blink::VRDisplayPtr&);
 
     void updatePose();
 
     void beginPresent(ScriptPromiseResolver*);
     void forceExitPresent();
 
     void updateLayerBounds();
+    void disconnected();
 
     VRController* controller();
 
 private:
     void onFullscreenCheck(TimerBase*);
 
     Member<NavigatorVR> m_navigatorVR;
     unsigned m_displayId;
     String m_displayName;
     bool m_isConnected;
@@ skipping 10 matching lines @@
     double m_depthFar;
 
     Timer<VRDisplay> m_fullscreenCheckTimer;
 };
 
 using VRDisplayVector = HeapVector<Member<VRDisplay>>;
 
 } // namespace blink
 
 #endif // VRDisplay_h