Update from https://crrev.com/317530

mojo/tools/android_mojo_shell.py

 #!/usr/bin/env python
 # Copyright 2014 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.
 
 import argparse
 import logging
 import sys
 
 from mopy.config import Config
@@ skipping 21 matching lines @@
 def main():
   logging.basicConfig()
 
   parser = argparse.ArgumentParser(usage=USAGE)
 
   debug_group = parser.add_mutually_exclusive_group()
   debug_group.add_argument('--debug', help='Debug build (default)',
                            default=True, action='store_true')
   debug_group.add_argument('--release', help='Release build', default=False,
                            dest='debug', action='store_false')
-  debug_group.add_argument('--target-arch',
+  debug_group.add_argument('--target-cpu',
                            help='CPU architecture to run for.',
                            choices=['x64', 'x86', 'arm'])
   launcher_args, args = parser.parse_known_args()
 
   config = Config(target_os=Config.OS_ANDROID,
-                  target_arch=launcher_args.target_arch,
+                  target_cpu=launcher_args.target_cpu,
                   is_debug=launcher_args.debug)
 
   args.append(android.PrepareShellRun(config))
   android.CleanLogs()
   p = android.ShowLogs()
   android.StartShell(args, sys.stdout, p.terminate)
 
   return 0
 
 
 if __name__ == "__main__":
   sys.exit(main())