[Highlight Events] Because of the super weird event propagation, it is unclear how event.eventPhase works with the events

[smaug----]

If event.target stays as the element, and when currentTarget == target, that is supposed to be AT_TARGET phase.
But since propagation goes through Highlight, the examples seem to hint that eventPhase starts to work in some new way and it would probably break sites.

[snianu]

@dandclark FYI..