[Android] Add a "quiet" flag so KillAll doesn't complain if no processes killed

build/android/provision_devices.py

 #!/usr/bin/env python
 #
 # Copyright (c) 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.
 
 """Provisions Android devices with settings required for bots.
 
 Usage:
   ./provision_devices.py [-d <device serial number>]
@@ skipping 214 matching lines @@
   """Pushes and launches the adb_reboot binary on the device.
 
   Arguments:
     device: The DeviceUtils instance for the device to which the adb_reboot
             binary should be pushed.
     target: The build target (example, Debug or Release) which helps in
             locating the adb_reboot binary.
   """
   logging.info('Will push and launch adb_reboot on %s' % str(device))
   # Kill if adb_reboot is already running.
-  try:
-    # Don't try to kill adb_reboot more than once. We don't expect it to be
-    # running at all.
-    device.KillAll('adb_reboot', blocking=True, timeout=2, retries=0)
-  except device_errors.CommandFailedError:
-    # We can safely ignore the exception because we don't expect adb_reboot
-    # to be running.
-    pass
+  device.KillAll('adb_reboot', blocking=True, timeout=2, quiet=True)
   # Push adb_reboot
   logging.info('  Pushing adb_reboot ...')
   adb_reboot = os.path.join(constants.DIR_SOURCE_ROOT,
                             'out/%s/adb_reboot' % target)
   device.PushChangedFiles([(adb_reboot, '/data/local/tmp/')])
   # Launch adb_reboot
   logging.info('  Launching adb_reboot ...')
   device.RunShellCommand(
       [device.GetDevicePieWrapper(), '/data/local/tmp/adb_reboot'],
       check_return=True)
@@ skipping 65 matching lines @@
   args = parser.parse_args()
   constants.SetBuildType(args.target)
 
   run_tests_helper.SetLogLevel(args.verbose)
 
   return ProvisionDevices(args)
 
 
 if __name__ == '__main__':
   sys.exit(main())