GitLab

This CL fixes the order in which the notifications to update the
primary account are being fired. The scenario that failed before
this CL was the following (covered in test
SigninManagerTest.UnconsentedPrimaryAccountUpdatedOnSyncConsentRevoked):
1. Account A and B are signed in with this order in the cookie jar.
2. Unconsented primary account: A
3. User enables sync with account B. B becomes the primary account
4. User revokes sync consent.
5. Unconsented primary account is reverted to B

Before this CL, 2 notifications were sent with primary account changed
in the wrong order:
1. { previous_state: { primary_account: gaia_id_for_me2_gmail.com,
                       consent_level:NotRequired }
     current_state: { primary_account: gaia_id_for_me_gmail.com,
                      consent_level:NotRequired } }
2. { previous_state: { primary_account: gaia_id_for_me2_gmail.com,
                       consent_level:Sync },
     current_state: { primary_account: gaia_id_for_me2_gmail.com,
                       consent_level:NotRequired } }

This CL fixes this order, and ensures that notification 2 above is
correctly sent before notification 1.

The change in the CL is fairly complex as it also updates the
SigninManager to observe OnPrimaryAccountChanged notifications which
is required as OnUnconsentedPrimaryAccountSet is deprecated.

Bug: 1163126

Change-Id: I047014ce9bc569040d44121d90670d375f8fba62
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2613971
Commit-Queue: Mihai Sardarescu <msarda@chromium.org>
Reviewed-by: Monica Basta <msalama@chromium.org>
Reviewed-by: David Roger <droger@chromium.org>
Cr-Commit-Position: refs/heads/master@{#841999}