WebXR critical blocker: Exiting WebXR AR session leaves browser window blank, unable to render any content

[milesgreen]

@Laszlo - Awesome! Thanks for looking at it.

Please also see:

Dark Mode prevents WebXR AR session from displaying any content

Issue: When viewing WebXR AR content in Dark Mode, the camera feed of the real world and the 3D AR content is completely blank / black. When viewing the same WebXR AR content not in Dark Mode, the camera feed and AR content display as expected. Steps to recreate: Switch Samsung Internet into Dark Mode Visit some WebXR AR content, for example: Barebones AR Hit ‘Enter AR’ Observe that the DOM overlay is still visible and indicates that a WebXR session is in progress, but the camera feed and…