Add support of vrdisplayconnect and vrdisplaydisconnect event

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

Index: third_party/WebKit/Source/modules/vr/VRDisplay.cpp
diff --git a/third_party/WebKit/Source/modules/vr/VRDisplay.cpp b/third_party/WebKit/Source/modules/vr/VRDisplay.cpp
index 62d6d4260614e4a8f3349bb4d9c769756304964a..0b3d53df6e764a104f6e81ee0e8d7cf2e6417301 100644
--- a/third_party/WebKit/Source/modules/vr/VRDisplay.cpp
+++ b/third_party/WebKit/Source/modules/vr/VRDisplay.cpp
@@ -83,6 +83,12 @@ void VRDisplay::update(const device::blink::VRDisplayPtr& display)
     }
 }
 
+void VRDisplay::disconnected()
+{
+    if (m_isConnected)
+        m_isConnected = !m_isConnected;
+}
+
 bool VRDisplay::getFrameData(VRFrameData* frameData)
 {
     updatePose();