Description
After #11214
- Make sure we always subscribe to changes in our own devices list (fairly certain we already do)
- If cross-signing labs flag is enabled, whenever we fetch new devices for our own account (except the first time),
determine if a new device was added by subtracting the set of previous devices from the new set. If there are new devices, determine trust for them. If there are new, untrusted devices, show the flow for a new sign in (existing session).if there are untrusted devices, show the 'New Sign In' toast. In future we may want to adjust the toast, eg. to say "Unverified Sign In" for sign-ins we already know about to avoid telling users thewy have new signs ins after they turn on cross-signing. - Implement new sign in (existing session) flow. Careful to swallow incoming verification requests from that device, ie. not show them in the normal way.
Q: Is the unverified-devices nag bar shown to start with, then the new-sign-in flow is shown when you click on that?
A: The nag bar is now a toast, but at first the 'New Sign In' toast is shown, then if the user clicks on 'Review' this takes them to "New Sign In" under "Verify New Device" / "on existing session".