Fix handling of absent flags file in adb_command_line.py.

build/android/adb_command_line.py

 #!/usr/bin/python
 # Copyright 2015 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.
 
 """Utility for reading / writing command-line flag files on device(s)."""
 
 import argparse
 import sys
 
@@ skipping 26 matching lines @@
   as_root = not args.device_path.startswith('/data/local/tmp/')
 
   devices = device_utils.DeviceUtils.HealthyDevices(device_arg=args.devices,
                                                     default_retries=0)
   all_devices = device_utils.DeviceUtils.parallel(devices)
 
   def print_args():
     def read_flags(device):
       try:
         return device.ReadFile(args.device_path, as_root=as_root).rstrip()
-      except device_errors.AdbCommandFailedError:
+      except device_errors.CommandFailedError:
         return ''  # File might not exist.
 
     descriptions = all_devices.pMap(lambda d: d.build_description).pGet(None)
     flags = all_devices.pMap(read_flags).pGet(None)
     for d, desc, flags in zip(devices, descriptions, flags):
       print '  %s (%s): %r' % (d, desc, flags)
 
   # No args == print flags.
   if not remote_args:
     print 'Existing flags (in %s):' % args.device_path
@@ skipping 17 matching lines @@
     device.RunShellCommand(['chmod', '0664', args.device_path], as_root=as_root)
 
   all_devices.pMap(write_flags).pGet(None)
   print 'Wrote flags to %s' % args.device_path
   print_args()
   return 0
 
 
 if __name__ == '__main__':
   sys.exit(main())