Chrome Version: 66.0.3343.0 
OS: Android O
Device: Pixel 2

What steps will reproduce the problem?
(1) Go to https://webvr.info/samples/03-vr-presentation.html
(2) Press Enter VR button
(3) Place device in headset and follow DON flow

What is the expected result? proper transition from DON flow to WebVR presentation

What happens instead? System menu appears briefly after DON flow. (Vertical white bar on right side of screen). See attached video.

Doesn't happen with VR browsing.
 

Deleted: screen.mp4 26.8 MB

screen.mp4 26.8 MB Download