GitLab

Remove the custom C++ class IdentityManagerObserver and rely on the
new API from //services/identity/public/objc instead.

Bug: 903262
Change-Id: I32c3d46bbd6c1cd45c092c859ef303d9cd6b240f
Reviewed-on: https://chromium-review.googlesource.com/c/1326151
Commit-Queue: Mario Sanchez Prada <mario@igalia.com>
Reviewed-by: Colin Blundell <blundell@chromium.org>
Reviewed-by: Sergio Collazos <sczs@chromium.org>
Cr-Commit-Position: refs/heads/master@{#607701}