[MR extension] Don't call chooseDesktopMedia() with a tab ID

Calling chooseDesktopMedia() with the tab ID of the active tab so that we can later look up the capture stream with the same tab ID is a hack that results in weird behavior like capture failing if the active tab doesn't use HTTPS. This CL removes such use of the active tab ID.

This change causes the capture stream to be associated with the event page's WebContents. The native Mirroring Service will now need to obtain a reference to that in order to look up the capture stream, in order for the Mirroring Service to work with the extension MRP. That change will need to happen on the Chromium side.

crbug.com/972874

PiperOrigin-RevId: 253854972
1 file changed