GitLab

Update PowerManagerClient to pass serialized protocol
buffers to powerd's SetScreenBrightness D-Bus method instead
of passing native D-Bus arguments to
SetScreenBrightnessPercent. This allows passing the reason
for the request.

Bug: 881786
Change-Id: I753fb19f45f99acf3142d91ba96cf3650699df33
Reviewed-on: https://chromium-review.googlesource.com/1244551Reviewed-by: Jia Meng <jiameng@chromium.org>
Reviewed-by: Luis Hector Chavez <lhchavez@chromium.org>
Commit-Queue: Dan Erat <derat@chromium.org>
Cr-Commit-Position: refs/heads/master@{#594576}