Merge lp://qastaging/~dobey/ubuntu-system-settings/token-deleted into lp://qastaging/ubuntu-system-settings

Handle the credentialsDeleted signal appropriately.

To test this is a bit difficult. You will need a U1 account on the phone, which is not added to the "unconfined" ACL. This can be done on the latest images, by manually deleting the ACL entry in the database after creating an account.

Close system settings.
Open the terminal app or use phablet-shell to perform the sqlite work.

First get the account ID:

# account-console list

That will print a list of account IDs and their provider. Take a note of the "ubuntuone" account, and use it as a parameter for the next command:

# account-console show <account-id>

Look for the "CredentialsId" field; let's call its value $ACCOUNT_ID.
Then you need to delete the entry from the ACL table in the signon database.

# sqlite3 .config/signond/signon.db
sqlite> delete from ACL where identity_id=$ACCOUNT_ID;
sqlite> delete from OWNER where identity_id=$ACCOUNT_ID;

Now, open system settings, and go to the Updates page. Without this branch, you should see the button requesting you to log in to U1 to get app updates. With this branch, the online accounts UI should pop up directly to the U1 page requesting to log in again.