[observe.html]
  [test8: simple content-box observation]
    expected: [PASS, FAIL]

  [test9: simple content-box observation but keep border-box size unchanged]
    expected: [PASS, FAIL]

  [test10: simple border-box observation]
    expected: [PASS, FAIL]

  [test11: simple observation with vertical writing mode]
    expected: FAIL

  [test12: no observation is fired after the change of writing mode when box's specified size comes from logical size properties.]
    expected: FAIL

  [test13: an observation is fired after the change of writing mode when box's specified size comes from physical size properties.]
    expected: FAIL

  [test14: observe the same target but using a different box should override the previous one]
    expected: FAIL

  [test15: an observation is fired with box dimensions 0 when element's display property is set to inline]
    expected: FAIL

  [test16: observations fire once with 0x0 size for non-replaced inline elements]
    expected: FAIL

  [test17: Box sizing snd Resize Observer notifications]
    expected: FAIL

  [test18: an observation is fired when device-pixel-content-box is being observed]
    expected: FAIL