In details, the policy is for session management, rather than user
management. So, move it out from UserManager.
This helps us writing UserManger related unittest easily,
because we do not need to set up local state with
multi-user sign-in policy, which has dependency issue.
BUG=278643115
TEST=Tryjob
Change-Id: Ic0fdd1bc2bd514ce6a9373d89caf5a7c4a7e3c83
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/6025366
Commit-Queue: Hidehiko Abe <hidehiko@chromium.org>
Reviewed-by: Xiyuan Xia <xiyuan@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1386582}
1bce59ec04