Aframe WebVR Polyfill screen.orientation.lock() failed due to A call to screen.orientation.lock()

Question

On Chrome 70 with Aframe 0.8.2

When entering VR mode I get this error which freezes and sometimes crashes the browser, or results in a black video.

screen.orientation.lock() failed due to A call to screen.orientation.lock() or screen.orientation.unlock() canceled this call.

This appears to be coming from the WebVR Polyfill and I assume there is a change in Chrome that requires the screen orientation lock to be a promise or similar?