GitLab

AuthenticatorImpl doesn't support the callbacks being made immediately.
Instead, defer them via the current MessageLoop.

Change-Id: I57b43049e8dca8e1d113f86eb1ea5728e7d953a8
Reviewed-on: https://chromium-review.googlesource.com/963096Reviewed-by: Jan Wilken Dörrie <jdoerrie@chromium.org>
Reviewed-by: Balazs Engedy <engedy@chromium.org>
Commit-Queue: Adam Langley <agl@chromium.org>
Cr-Commit-Position: refs/heads/master@{#543710}