firefox/testing/web-platform/meta/dom/nodes/insertion-removing-steps/insertion-removing-steps-iframe.window.js.ini

[insertion-removing-steps-iframe.window.html]
  [Insertion steps: load event fires synchronously *after* iframe DOM insertion, as part of the iframe element's insertion steps]
    expected: FAIL

  [Removing steps (innerHTML): script does not run synchronously during iframe destruction]
    expected: FAIL

  [Removing steps (replaceChildren): script does not run synchronously during iframe destruction]
    expected: FAIL

  [Removing steps (remove): script does not run synchronously during iframe destruction]
    expected: FAIL