GitLab

First batch of KerberosCredentialsManager unit tests. Also adds a test
interface to FakeKerberosClient to
- Set the task delay (tests set it to 0 to speed up the tests),
- Record which functions are called for testing.

BUG=chromium:952251
TEST=Unit tests succeed

Change-Id: I14b3790d1dfb9809e0bc6b7b59a9b58d196e1929
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1760951
Commit-Queue: Lutz Justen <ljusten@chromium.org>
Reviewed-by: Roman Sorokin [CET] <rsorokin@chromium.org>
Reviewed-by: Lutz Justen <ljusten@chromium.org>
Auto-Submit: Lutz Justen <ljusten@chromium.org>
Cr-Commit-Position: refs/heads/master@{#693140}