Wake Lock API: Add implementation for System wake lock

This patch enables system wake lock on blink side by making use of
ServiceManager Connector and WakeLockProvider.

BUG=873030,257511

Change-Id: Ie4cb38124d0072d12d663ef4d1ae7311a1233460
Reviewed-on: https://chromium-review.googlesource.com/c/1256220
Commit-Queue: Mrunal Kapade <mrunal.kapade@intel.com>
Reviewed-by: Kinuko Yasuda <kinuko@chromium.org>
Reviewed-by: Mounir Lamouri <mlamouri@chromium.org>
Cr-Commit-Position: refs/heads/master@{#596856}
7 files changed