[active.window.html]
  [document.open() removes the document's children (non-active document with an associated Window object; frame is removed)]
    bug: https://bugzilla.mozilla.org/show_bug.cgi?id=1520333
    expected: FAIL

  [document.open() removes the document's children (active but not fully active document)]
    bug: https://bugzilla.mozilla.org/show_bug.cgi?id=1520333
    expected: FAIL

