GitLab

Controller will only create the adaptive brightness system after a user
session has started. The model will be personalized to the primary user
profile, ie. the first signed-in user.

Bug: 881215
Change-Id: Ib54fb5c8a05c2a47eec4ca1035d72e24e8183921
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1984794Reviewed-by: Xiyuan Xia <xiyuan@chromium.org>
Commit-Queue: Jia Meng <jiameng@chromium.org>
Cr-Commit-Position: refs/heads/master@{#728305}