Return 1 ony if no online device presents.

build/android/buildbot/bb_device_status_check.py

 #!/usr/bin/env python
 #
 # Copyright 2013 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 """A class to keep track of devices across builds and report state."""
 import logging
 import optparse
 import os
@@ skipping 323 matching lines @@
                                               'unimportant')
     for serial, battery in zip(devices, batteries):
       perf_tests_results_helper.PrintPerfResult('DeviceBattery', serial,
                                                 [battery], '%',
                                                 'unimportant')
 
   if False in fail_step_lst:
     # TODO(navabi): Build fails on device status check step if there exists any
     # devices with critically low battery. Remove those devices from testing,
     # allowing build to continue with good devices.
-    return 1
+    return 2
 
   if not devices:
     return 1
 
 
 if __name__ == '__main__':
   sys.exit(main())