This is a testharness.js-based test.
[FAIL] XRAnchor interface: operation requestPersistentHandle()
  assert_own_property: interface prototype object missing non-static operation expected property "requestPersistentHandle" missing
[FAIL] XRSession interface: attribute persistentAnchors
  assert_true: The prototype object must have a property "persistentAnchors" expected true got false
[FAIL] XRSession interface: operation restorePersistentAnchor(DOMString)
  assert_own_property: interface prototype object missing non-static operation expected property "restorePersistentAnchor" missing
[FAIL] XRSession interface: operation deletePersistentAnchor(DOMString)
  assert_own_property: interface prototype object missing non-static operation expected property "deletePersistentAnchor" missing
Harness: the test ran to completion.