[getComputedStyle-pseudo.html]
  [Item-based blockification of nonexistent pseudo-elements]
    expected: FAIL

  [Resolution of nonexistent pseudo-element styles]
    expected: FAIL

  [Unknown pseudo-elements throw]
    expected: FAIL

  [Unknown pseudo-elements]
    expected: FAIL

  [Unknown pseudo-element with a known string (ex: marker)]
    expected: FAIL