Stable unexpected results (1): 
  ▶ OK /mixed-content/tentative/autoupgrades/video-upgrade.https.sub.html
  │   ▶ FAIL [expected PASS] Video autoupgraded
  │   │   → assert_equals: Length. expected 1 but got Infinity
  │   │ 
  │   │ assert_video_loads/i.oncanplaythrough<@https://web-platform.test:8443/mixed-content/tentative/autoupgrades/video-upgrade.https.sub.html:19:26
  │   │ Test.prototype.step@https://web-platform.test:8443/resources/testharness.js:2869:25
  └   └ Test.prototype.step_func_done/<@https://web-platform.test:8443/resources/testharness.js:2944:32