Stop using [Client=...] feature of Mojom for BatteryMonitor

device/battery/battery_status_service.h

Index: device/battery/battery_status_service.h
diff --git a/device/battery/battery_status_service.h b/device/battery/battery_status_service.h
index fd52b6b439f3e2b7f9a5589f36ab7343b34fb0d2..a4cfac7dd078b69c057a7c46951555f4600e95db 100644
--- a/device/battery/battery_status_service.h
+++ b/device/battery/battery_status_service.h
@@ -30,6 +30,7 @@ class DEVICE_BATTERY_EXPORT BatteryStatusService {
 
   // Adds a callback to receive battery status updates.  Must be called on the
   // main thread. The callback itself will be called on the main thread as well.
+  // NOTE: The callback may be run before AddCallback returns!
   scoped_ptr<BatteryUpdateSubscription> AddCallback(
       const BatteryUpdateCallback& callback);