system_api: add constants for {Get|Set}Channel.

BUG=chromium:219292
TEST=none

Change-Id: I2f1b7e3122c059c939f7fef87404a3bb120122c1
Reviewed-on: https://gerrit.chromium.org/gerrit/59427
Reviewed-by: Yuri Gorshenin <ygorshenin@chromium.org>
Reviewed-by: Steven Bennetts <stevenjb@chromium.org>
Tested-by: Yuri Gorshenin <ygorshenin@chromium.org>
Commit-Queue: Yuri Gorshenin <ygorshenin@chromium.org>
1 file changed
tree: d87b09b4eeb3b78d768698a5812216b18f75f764
  1. dbus/
  2. switches/
  3. README
  4. system_api.gyp