GitLab

Adds a power_scheduler component and the foundational framework to vote
on and determine a process-wide PowerMode, which will later be used as
input to the yet-to-be-implemented power scheduler.

We will instrument different Chromium components to provide inputs to
power mode detection. Each instrumentation site will instantiate a
PowerModeVoter, which votes on the process's power mode. The votes are
collected by a PowerModeArbiter, which decides the overall mode for the
process based on a prioritization mechanism.

Internal design doc: http://go/chromium-process-power-scheduler
(sorry, no public docs yet.)

Bug: 1166695
Change-Id: Idc70c8c5202d45ba44cddffa3fba9a5da41257fc
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2628958Reviewed-by: Ted Choc <tedchoc@chromium.org>
Reviewed-by: Sami Kyöstilä <skyostil@chromium.org>
Commit-Queue: Eric Seckler <eseckler@chromium.org>
Cr-Commit-Position: refs/heads/master@{#844867}