GitLab

Update PowerManagerClient to listen for the new
ScreenBrightnessChanged D-Bus signal emitted by powerd,
which contains a protobuf and replaces the earlier
BrightnessChanged signal.

Also update Chrome to decode protobufs from
KeyboardBrightnessChanged signals.

Bug: 811138
Change-Id: If313801aa516850d904540736a2dee63bac7d6e7
Reviewed-on: https://chromium-review.googlesource.com/952578
Commit-Queue: Dan Erat <derat@chromium.org>
Reviewed-by: Luis Hector Chavez <lhchavez@chromium.org>
Reviewed-by: Ryo Hashimoto <hashimoto@chromium.org>
Cr-Commit-Position: refs/heads/master@{#542160}