webxr-samples: WebXR samples not working with Oculus or Vive in Chrome 77

This year the WebXR API in Chrome has been going through a lot of changes and that is fine. However, I am starting to wonder if I have something incorrectly setup. I have been unable to get WebXR going on my desktop HMDs since Chrome 74.

We just get an exception when ‘requestSession’ is called with ‘immersive-vr’. Note: I am only interested in desktop VR, not mobile, which seems to be more common.

  navigator.xr.requestSession('immersive-vr').then(onSessionStarted);

Version 77.0.3865.90 (Official Build) (64-bit)

All I need is a sample that works on a current build of Chrome with Oculus Rift or Vive. Is it possible I have flags not configured correctly? I have tried enabling/disabling everything and various combinations, and to no avail. Always the Uncaught DOMException before any client code is called.

My current solution is to downgrade to Chrome 74, but there must be a reason nothing is working.

Please mr @toji , any tips would save me right now.