[relevant-mutations.html]
  [referrerpolicy no-referrer-when-downgrade to empty, src already set]
    expected: FAIL

  [referrerpolicy no-referrer-when-downgrade to absent, src already set]
    expected: FAIL

  [referrerpolicy no-referrer to invalid, src already set]
    expected: FAIL

  [referrerpolicy no-referrer to empty, src already set]
    expected: FAIL

  [referrerpolicy no-referrer-when-downgrade to invalid, src already set]
    expected: FAIL

  [referrerpolicy no-referrer to absent, src already set]
    expected: FAIL

  [srcset is set to same value]
    expected: FAIL

  [sizes is set to same value]
    expected: FAIL