Chrome Version: 69.0.3487.0
OS: Android N
Device: Pixel
VRCore: 1.16.201071054

Note that this seems to happen specifically when permissions are granted on https://immersive-web.github.io/webxr-samples/tests/permission-request.html
I tested using the https://permissions.site site and didn't see the same effect.

What steps will reproduce the problem?
(1) Reset all Chrome permissions. Settings > Apps > Chrome > Storage > Manage Space, click "Clear all data"
(2) Enable all permissions in Chrome. Settings > Apps > Chrome > Permissions, then enable all of them.
(3) Go to https://immersive-web.github.io/webxr-samples/tests/permission-request.html and enter VR Browsing.
(4) Press enter VR button
(5) Using cursor, select the microphone icon and grant permissions.
(6) Press the app button on the controller to exit WebXR presentation.
Note that the permission indicator appears at the top of the content quad.
(7) Open the menu in the Omnibox and press the refresh button.

What is the expected result? The background doesn't flash or reload, only the content quad reloads.

What happens instead? The entire view flashes black. See video attached.
 

Deleted: refresh_with_permissions_indicator_flash.mp4 4.5 MB

	refresh_with_permissions_indicator_flash.mp4 4.5 MB View Download