oldList definition in enumerateDevices is unclear

[youennf]

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.

[youennf]

testing suggests this is not implemented this way in browsers currently

https://jsfiddle.net/63Lorgkq/

[youennf]

Above jsfiddle.net tends to show that browsers do not implement step 3 of https://w3c.github.io/mediacapture-main/#dom-mediadevices-enumeratedevices.

Also, step 8.2 is not very clear in whether filteredList is a deep clone or not of resultList.
If not, the same object would be returned but the label getter would return the label conditionally on the 'device-info' permission. This is probably worth a separate issue.

[youennf]

Closing since remaining items were fixed in #620