[mediacapture-main] oldList definition in enumerateDevices is unclear (#604)

youennf has just created a new issue for https://github.com/w3c/mediacapture-main:

== oldList definition in enumerateDevices is unclear ==
oldList in enumerateDevices seems to be per browsing session.
I guess it should be scoped by document, as groupId is per-document and we also want deviceIds to be partitioned per origin, which oldList might mess up with.

It is also not clear when oldList is set/built/updated. Is it set the first time enumerateDevices is called? Or is oldList the result of the last time enumerateDevices is called? Or is it a consolidation of all devices exposed during the various enumerateDevices calls?

I am also not very clear about the purpose of oldList as well. It seems that this is either an optimization (unnecessary then), a way to make sure deviceId/groupId are consistent call after call (but this is insufficient for deviceIds which are living longer than the browsing session and somehow redundant with MediaDeviceInfo.deviceId/groupId definitions), or a way for device === when enumerateDevices is called more than once (testing suggests this is not implemented this way in browsers currently).

I would tend to try removing oldList.

Please view or discuss this issue at https://github.com/w3c/mediacapture-main/issues/604 using your GitHub account