Intermittent failure in /html/canvas/offscreen/convert-to-blob/offscreencanvas.convert.to.blob.html

[jdm]

  ▶ Unexpected subtest result in /html/canvas/offscreen/convert-to-blob/offscreencanvas.convert.to.blob.html:
  │ FAIL [expected PASS] Test that call convertToBlob on a OffscreenCanvas with tainted origin throws exception
  │   → offscreenCanvas.convertToBlob is not a function
  │ 
  │ img.onload<@http://web-platform.test:8000/html/canvas/offscreen/convert-to-blob/offscreencanvas.convert.to.blob.html:155:25
  │ Test.prototype.step@http://web-platform.test:8000/resources/testharness.js:1988:25
  └ Test.prototype.step_func_done/<@http://web-platform.test:8000/resources/testharness.js:2029:32

[gterzian]

It reads like this one might be fixed via #24272