new_contents: #!/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.
  
  """Runs semi-automated update testing on a non-rooted device."""
  import logging
  import optparse
  import os
  import shutil
  import sys
  import time
  
  from pylib import android_commands
  
  
  def _SaveAppData(adb, package_name, from_apk=None, data_dir=None):
    def _BackupAppData(data_dir=None):
      adb.Adb().SendCommand('backup %s' % package_name)
      backup_file = os.path.join(os.getcwd(), 'backup.ab')
      assert os.path.exists(backup_file), 'Backup failed.'
      if data_dir:
        if not os.path.isdir(data_dir):
          os.makedirs(data_dir)
        shutil.move(backup_file, data_dir)
        backup_file = os.path.join(data_dir, 'backup.ab')
      print 'Application data saved to %s' % backup_file
  
    if from_apk:
      logging.info('Installing %s...', from_apk)
      output = adb.Install(from_apk, reinstall=True)
      if 'Success' not in output:
        raise Exception('Unable to install %s. output: %s' % (from_apk, output))
  
    raw_input('Set the application state. Once ready, press enter and '
              'select "Backup my data" on the device.')
    _BackupAppData(data_dir)
  
  
  def _VerifyAppUpdate(adb, to_apk, app_data, from_apk=None):
    def _RestoreAppData():
      assert os.path.exists(app_data), 'Backup file does not exist!'
      adb.Adb().SendCommand('restore %s' % app_data)
      # It seems restore command is not synchronous.
      time.sleep(15)
  
    if from_apk:
      logging.info('Installing %s...', from_apk)
      output = adb.Install(from_apk, reinstall=True)
      if 'Success' not in output:
        raise Exception('Unable to install %s. output: %s' % (from_apk, output))
  
    logging.info('Restoring the application data...')
    raw_input('Press enter and select "Restore my data" on the device.')
    _RestoreAppData()
  
    logging.info('Verifying that %s cannot be installed side-by-side...',
                 to_apk)
    output = adb.Install(to_apk)
    if 'INSTALL_FAILED_ALREADY_EXISTS' not in output:
      if 'Success' in output:
        raise Exception('Package name has changed! output: %s' % output)
      else:
        raise Exception(output)
  
    logging.info('Verifying that %s can be overinstalled...', to_apk)
    output = adb.Install(to_apk, reinstall=True)
    if 'Success' not in output:
      raise Exception('Unable to install %s.\n output: %s' % (to_apk, output))
    logging.info('Successfully updated to the new apk. Please verify that the '
                 'the application data is preserved.')
  
  
  def main():
    logger = logging.getLogger()
    logger.setLevel(logging.DEBUG)
    desc = (
        'Performs semi-automated application update verification testing. '
        'When given --save, it takes a snapshot of the application data '
        'on the device. (A dialog on the device will prompt the user to grant '
        'permission to backup the data.) Otherwise, it performs the update '
        'testing as follows: '
        '1. Installs the |from-apk| (optional). '
        '2. Restores the previously stored snapshot of application data '
        'given by |app-data| '
        '(A dialog on the device will prompt the user to grant permission to '
        'restore the data.) '
        '3. Verifies that |to-apk| cannot be installed side-by-side. '
        '4. Verifies that |to-apk| can replace |from-apk|.')
    parser = optparse.OptionParser(description=desc)
    parser.add_option('--package-name', help='Package name for the application.')
    parser.add_option('--save', action='store_true',
                      help=('Save a snapshot of application data. '
                            'This will be saved as backup.db in the '
                            'current directory if |app-data| directory '
                            'is not specifid.'))
    parser.add_option('--from-apk',
                      help=('APK to update from. This is optional if you already '
                            'have the app installed.'))
    parser.add_option('--to-apk', help='APK to update to.')
    parser.add_option('--app-data',
                      help=('Path to the application data to be restored or the '
                            'directory where the data should be saved.'))
    (options, args) = parser.parse_args()
  
    if args:
      parser.print_help(sys.stderr)
      parser.error('Unknown arguments: %s.' % args)
  
    if len(android_commands.GetAttachedDevices()) != 1:
      parser.error('Exactly 1 device must be attached.')
    adb = android_commands.AndroidCommands()
  
    if options.from_apk:
      assert os.path.isfile(options.from_apk)
  
    if options.save:
      if not options.package_name:
        parser.print_help(sys.stderr)
        parser.error('Missing --package-name.')
      _SaveAppData(adb, options.package_name, from_apk=options.from_apk,
                   data_dir=options.app_data)
    else:
      if not options.to_apk or not options.app_data:
        parser.print_help(sys.stderr)
        parser.error('Missing --to-apk or --app-data.')
      assert os.path.isfile(options.to_apk)
      assert os.path.isfile(options.app_data)
      _VerifyAppUpdate(adb, options.to_apk, options.app_data,
                       from_apk=options.from_apk)
  
  
  if __name__ == '__main__':
    main()
  
subject: Add a tool for application update verification.