new_contents: #!/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.
  
  """Generate a CL to roll a DEPS entry to the specified revision number and post
  it for review so that the CL will land automatically if it passes the
  commit-queue's checks.
  """
  
  import logging
  import optparse
  import os
  import re
  import sys
  
  SCRIPT_DIR = os.path.dirname(os.path.realpath(__file__))
  SRC_DIR = os.path.abspath(os.path.join(SCRIPT_DIR, os.pardir, os.pardir, os.pardir))
  sys.path.insert(0, os.path.join(SRC_DIR, 'build'))
  import find_depot_tools
  import scm
  import subprocess
  
  IS_WINDOWS = sys.platform.startswith('win')
  
  def die_with_error(msg):
    print >> sys.stderr, msg
    sys.exit(1)
  
  
  def process_deps(path, project, new_rev, is_dry_run):
    """Update project_revision to |new_issue|.
  
    A bit hacky, could it be made better?
    """
    content = open(path).read()
    # Hack for Blink to get the AutoRollBot running again.
    if project == "blink":
      project = "webkit"
    old_line = r"(\s+)'%s_revision': '([0-9a-f]{2,40})'," % project
    new_line = r"\1'%s_revision': '%s'," % (project, new_rev)
    new_content = re.sub(old_line, new_line, content, 1)
    old_rev = re.search(old_line, content).group(2)
    if not old_rev:
      die_with_error('Failed to update the DEPS file')
  
    if not is_dry_run and new_content != content:
      open(path, 'w').write(new_content)
    return old_rev
  
  
  class PrintSubprocess(object):
    """Wrapper for subprocess2 which prints out every command."""
    def __getattr__(self, attr):
      def _run_subprocess2(cmd, *args, **kwargs):
        print cmd
        sys.stdout.flush()
        return getattr(subprocess2, attr)(cmd, *args, **kwargs)
      return _run_subprocess2
  
  prnt_subprocess = PrintSubprocess()
  
  
  def main():
    tool_dir = os.path.dirname(os.path.abspath(__file__))
    parser = optparse.OptionParser(usage='%prog [options] <project> <new rev>',
                                   description=sys.modules[__name__].__doc__)
    parser.add_option('-v', '--verbose', action='count', default=0)
    parser.add_option('--dry-run', action='store_true')
    parser.add_option('-f', '--force', action='store_true',
                      help='Make destructive changes to the local checkout if '
                           'necessary.')
    parser.add_option('--commit', action='store_true', default=True,
                      help='(default) Put change in commit queue on upload.')
    parser.add_option('--no-commit', action='store_false', dest='commit',
                      help='Don\'t put change in commit queue on upload.')
    parser.add_option('-r', '--reviewers', default='',
                      help='Add given users as either reviewers or TBR as'
                      ' appropriate.')
    parser.add_option('--upstream', default='origin/master',
                      help='(default "%default") Use given start point for change'
                      ' to upload. For instance, if you use the old git workflow,'
                      ' you might set it to "origin/trunk".')
    parser.add_option('--cc', help='CC email addresses for issue.')
    parser.add_option('-m', '--message', help='Custom commit message.')
  
    options, args = parser.parse_args()
    logging.basicConfig(
        level=
            [logging.WARNING, logging.INFO, logging.DEBUG][
              min(2, options.verbose)])
    #if len(args) != 2:
    #  parser.print_help()
    #  exit(0)
  
    root_dir = os.path.dirname(tool_dir)
    os.chdir(root_dir)
  
    projects = [('src', '.'), ('v8', 'v8'), ('node', 'third_party/node-nw')]
    for project, path in projects:
      os.chdir(os.path.join(SRC_DIR, path))
      new_rev = subprocess.check_output(['git', 'rev-parse', 'HEAD'], shell=IS_WINDOWS).rstrip()
  
      # Silence the editor.
      os.environ['EDITOR'] = 'true'
  
      old_rev = process_deps(os.path.join(root_dir, 'DEPS'), 'nw_' + project, new_rev,
                             options.dry_run)
      if old_rev == new_rev:
        continue
      print '%s roll %s:%s' % (project, old_rev, new_rev)
      commit_msg = subprocess.check_output(['git', 'log', '-1', '--format=%s'], shell=IS_WINDOWS).rstrip()
      commit_msg = project + ": " + commit_msg
      os.chdir(root_dir)
      subprocess.check_output(['git', 'add', 'DEPS'], shell=IS_WINDOWS)
      subprocess.check_output(['git', 'commit', '--quiet', '-m', commit_msg], shell=IS_WINDOWS)
      break
    return 0
  
  
  if __name__ == '__main__':
    sys.exit(main())
  
subject: add roll-deps.py