[popover-events.html]
  [The "beforetoggle" event (listener) get properly dispatched for popovers]
    expected: FAIL

  [The "beforetoggle" event (attribute) get properly dispatched for popovers]
    expected: FAIL

  [The "beforetoggle" event is cancelable for the "opening" transition]
    expected: FAIL

  [The "beforetoggle" event is not fired for element removal]
    expected: FAIL

  [The "toggle" event is coalesced]
    expected: FAIL