cros: Update charging not reliable battery status

ash/system/chromeos/power/tray_power.cc

Index: ash/system/chromeos/power/tray_power.cc
diff --git a/ash/system/chromeos/power/tray_power.cc b/ash/system/chromeos/power/tray_power.cc
index 64f33f2d335a5874ca939b74bc501dee65f6b28d..7206fbe2154c3601fa568b042950cf0116d88186 100644
--- a/ash/system/chromeos/power/tray_power.cc
+++ b/ash/system/chromeos/power/tray_power.cc
@@ -217,11 +217,12 @@ TrayPower::~TrayPower() {
 // static
 bool TrayPower::IsBatteryChargingUnreliable(
     const chromeos::PowerSupplyStatus& supply_status) {
-  return
-      supply_status.battery_state ==
-          PowerSupplyStatus::NEITHER_CHARGING_NOR_DISCHARGING ||
-      supply_status.battery_state ==
-          PowerSupplyStatus::CONNECTED_TO_USB;
+  // Sometimes devices can get into a state where the battery is almost fully
+  // charged and the power subsystem reports "neither charging nor discharging"
+  // despite the battery not at 100%. For now, only report unreliable charging
+  // on USB.
+  // TODO(derat): Update this when the power manager code is refactored for M29.
+  return supply_status.battery_state == PowerSupplyStatus::CONNECTED_TO_USB;
 }
 
 // static