2 [Esc key does not count as user activation, so if it is the sole user interaction, that fires close but not cancel]
5 [A keydown listener can prevent the Esc keypress from being interpreted as a close request]
8 [A keyup listener can prevent the Esc keypress from being interpreted as a close request]
11 [A keypress listener can prevent the Esc keypress from being interpreted as a close request]
14 [close via synthesized Esc key must not work]