[animate.html]
  [Element.animate() accepts a keyframe sequence with a CSS variable as its property]
    expected: FAIL

  [Element.animate() accepts a property-indexed keyframes specification with a CSS variable as the property]
    expected: FAIL

  [Element.animate() accepts a two property (one shorthand and one of its shorthand components) two value property-indexed keyframes specification]
    expected: FAIL

  [animate() with pseudoElement parameter creates an Animation object for ::first-line]
    expected: FAIL
    bug: https://bugzilla.mozilla.org/show_bug.cgi?id=1615469

  [animate() with pseudoElement an Animation object targeting the correct pseudo-element for ::first-line]
    expected: FAIL
    bug: https://bugzilla.mozilla.org/show_bug.cgi?id=1615469

