Intermittent error in /webxr/getInputPose_pointer.https.html, /webxr/xrInputSource_emulatedPosition.https.html, /webxr/xrInputSource_profiles.https.html

[jdm]

  ▶ ERROR [expected OK] /webxr/getInputPose_pointer.https.html
  │   → source is undefined
  │ 
  └ CheckInvalidGrip@https://web-platform.test:8443/webxr/getInputPose_pointer.https.html:33:25
  ▶ Unexpected subtest result in /webxr/getInputPose_pointer.https.html:
  │ TIMEOUT [expected FAIL] XRInputSources with a target ray mode of 'tracked-pointer' properly communicate their poses
  └   → Test timed out
  ▶ ERROR [expected OK] /webxr/xrInputSource_emulatedPosition.https.html
  │   → source is undefined
  │ 
  └ CheckPositionNotEmulated@https://web-platform.test:8443/webxr/xrInputSource_emulatedPosition.https.html:32:25
  ▶ Unexpected subtest result in /webxr/xrInputSource_emulatedPosition.https.html:
  │ TIMEOUT [expected FAIL] Poses from XRInputSource.gripSpace have emulatedPosition set properly
  └   → Test timed out

When this occurs, session.inputSources[0] is null, which suggests perhaps there's an event ordering issue around XR events and the rAF that checks for the input source?