GitLab

This CL also adds more log messages to make debugging those kinds of
errors easier in the future.

The bug was introduced in a refactoring some time ago, where the special
handling for empty access tokens was lost and there was no unit test to
catch this.

Bug: b/170934170
Change-Id: Ib251a84fd032f6b72b278bc87aad2a8f48c8df9b
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2517441
Commit-Queue: Clemens Arbesser <arbesser@google.com>
Reviewed-by: Marian Fechete <marianfe@google.com>
Reviewed-by: Sandro Maggi <sandromaggi@google.com>
Cr-Commit-Position: refs/heads/master@{#823568}