Isolate a presenting VR device from pages other than the one presenting.

device/vr/vr_service_impl.h

Index: device/vr/vr_service_impl.h
diff --git a/device/vr/vr_service_impl.h b/device/vr/vr_service_impl.h
index a5c96ea0ab393ef70270af484d240a8e9bbe8e5f..e250ba55f2eb15db61390f19cb6add0fdb988ae6 100644
--- a/device/vr/vr_service_impl.h
+++ b/device/vr/vr_service_impl.h
@@ -39,9 +39,10 @@ class VRServiceImpl : public VRService {
   void GetPose(uint32_t index, const GetPoseCallback& callback) override;
   void ResetPose(uint32_t index) override;
 
-  void RequestPresent(uint32_t index) override;
+  void RequestPresent(uint32_t index,
+                      const RequestPresentCallback& callback) override;
   void ExitPresent(uint32_t index) override;
-  void SubmitFrame(uint32_t index) override;
+  void SubmitFrame(uint32_t index, VRPosePtr pose) override;
   void UpdateLayerBounds(uint32_t index,
                          VRLayerBoundsPtr leftBounds,
                          VRLayerBoundsPtr rightBounds) override;