firefox/testing/web-platform/meta/dom/nodes/insertion-removing-steps/Node-appendChild-script-and-iframe.tentative.html.ini

[Node-appendChild-script-and-iframe.tentative.html]
  [A script inserted atomically before an iframe (using a div) does not observe the iframe's contentWindow, since the 'script running' and 'iframe setup' both happen in order, after DOM insertion completes]
    expected: FAIL

  [A script inserted atomically before an iframe (using a DocumentFragment) does not observe the iframe's contentWindow, since the 'script running' and 'iframe setup' both happen in order, after DOM insertion completes]
    expected: FAIL

  [A script inserted atomically before an iframe (using a append() with multiple arguments) does not observe the iframe's contentWindow, since the 'script running' and 'iframe setup' both happen in order, after DOM insertion completes]
    expected: FAIL