Replace more ObserverList with base::ObserverList.

chromeos/network/network_sms_handler.h

Index: chromeos/network/network_sms_handler.h
diff --git a/chromeos/network/network_sms_handler.h b/chromeos/network/network_sms_handler.h
index 7cf4bffa3891fe90babd0fdab067f558332b8893..bb7fcb22a01655c177ea7430574d02400ced766a 100644
--- a/chromeos/network/network_sms_handler.h
+++ b/chromeos/network/network_sms_handler.h
@@ -89,7 +89,7 @@ class CHROMEOS_EXPORT NetworkSmsHandler : public ShillPropertyChangedObserver {
                                 DBusMethodCallStatus call_status,
                                 const base::DictionaryValue& properties);
 
-  ObserverList<Observer> observers_;
+  base::ObserverList<Observer> observers_;
   ScopedVector<NetworkSmsDeviceHandler> device_handlers_;
   ScopedVector<base::DictionaryValue> received_messages_;
   base::WeakPtrFactory<NetworkSmsHandler> weak_ptr_factory_;