CHERRY-PICK: power_status: Fix incorrect AC status check on Butterfly.

Under certain conditions, Butterfly EC will not report AC state
correctly for up to one minute following unplug. For Butterfly only,
also check the battery discharge state in case AC indicates ON.

TEST=Manual. Run power_LoadTest on Butterfly with newly disconnected
AC and verify detection is correct.

Change-Id: I5fe87c62e9408c1f8ad581dafed948879fbdc211
Original-Change-Id: Id76e9dbbc74a0577cfe37562e1f532e5ed25343d
Reviewed-by: Julius Werner <>
Commit-Queue: Shawn Nematbakhsh <>
Tested-by: Shawn Nematbakhsh <>
1 file changed