[at-scroll-timeline-source.html]
  [Source selector(<id-selector>) selects an element]
    expected: FAIL

  [Source none causes inactive timeline]
    expected: FAIL

  [Unknown source causes inactive timeline]
    expected: FAIL

  [Source with no layout box causes inactive timeline]
    expected: FAIL

  [Source auto selects scrollingElement of the document]
    expected: FAIL

  [Unspecified source behaves like auto]
    expected: FAIL

