Distinguish pause from transient-solo

[annevk]

A site would want to disable its own set of controls when "transient-solo" happens, but if the user did a hardware pause, the site would simply want to change the pause into a play button or some such.

[foolip]

I think that exposing the state (idle/active/interrupted) and events for transitions between those states ought to suffice to distinguish these two cases, because if a hardware button was used the session would still be active, with the media element(s) simply being paused.

[jernoble]

@foolip Agreed.

[xxyzzzq]

Closing this issue since we are moving audio focus out to a separate API.

[xxyzzzq]

This issue was moved to WICG/audio-focus#18