Clarification of "active"

[brianchirls]

We've got some very confusing terminology here as well as some poorly defined state.

1. The events onvrdisplayactivate and onvrdisplaydeactivate imply that "active" is defined as "the VRDisplay should be presented to" (or not). But we also have activeVRDisplays, which implies that "active" means "is currently presenting." These are contradictory and should be resolve. I suggest defining a single definition of "active" and renaming accordingly.

2. If you miss the onvrdisplayactivate event, whether because it fired before your script was ready or because the display was active (i.e. "should be presented to") before the page loaded, there is no way to know whether you should request presentation. We already have isConnected and isPresenting (the other definition of "active"), shouldn't we also have an analogous property here? Could be isMounted or isActive or something like that. Or maybe rather than a boolean, there could be an enum value that matches theVRDisplayEventReason.

[toji]

This issue was moved to immersive-web/webvr#12