system_api: Add type field to PowerSource message.

Update the PowerSupplyProperties protocol buffer's
PowerSource submessage to include a type field that includes
more information about the source.

BUG=chromium:831236
TEST=none

Change-Id: I0519d9806b638c5a639981b040ec6dba927efa2d
Reviewed-on: https://chromium-review.googlesource.com/1005624
Commit-Ready: Dan Erat <derat@chromium.org>
Tested-by: Dan Erat <derat@chromium.org>
Reviewed-by: Benson Leung <bleung@chromium.org>
Reviewed-by: Todd Broch <tbroch@chromium.org>
1 file changed