In the new specs, assume we have two external displays A and B. A was in mirror mode and B was not. We suspend the Chromebook and connect both displays and mirror mode should be turned. But in really, on resume, sometimes one of the external display is detected and the other is detected several seconds later. If A is detected first, we goes to mirror mode and then mirror mode persists after B is detected. However, if B is detected first, we goes to extended mode and then extended mode persists after A is detected.

Currently, display configuration is delayed on resume if external display is connected before suspend. We had a solution to delay the display configuration on resume if no external display is connected before suspend, but it will increase the time (several seconds) for resume in common use case (When there's no external display), which is not user-friendly.

So we need to figure out another way.