Start the documentation preview server on localhost only by default.

chrome/common/extensions/docs/server2/preview.py

 #!/usr/bin/env python
 # Copyright (c) 2012 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.
 
 # This helps you preview the apps and extensions docs.
 #
 #    ./preview.py --help
 #
 # There are two modes: server- and render- mode. The default is server, in which
@@ skipping 47 matching lines @@
     self.send_response(response.status)
     for k, v in response.headers.iteritems():
       self.send_header(k, v)
     self.end_headers()
     self.wfile.write(response.content.ToString())
 
 if __name__ == '__main__':
   parser = optparse.OptionParser(
       description='Runs a server to preview the extension documentation.',
       usage='usage: %prog [option]...')
+  parser.add_option('-a', '--address', default='127.0.0.1',
+      help='the local interface address to bind the server to')
   parser.add_option('-p', '--port', default='8000',
       help='port to run the server on')
   parser.add_option('-r', '--render', default='',
       help='statically render a page and print to stdout rather than starting '
            'the server, e.g. apps/storage.html. The path may optionally end '
            'with #n where n is the number of times to render the page before '
            'printing it, e.g. apps/storage.html#50, to use for profiling.')
   parser.add_option('-s', '--stat',
       help='Print profile stats at the end of the run using the given '
            'profiling option (like "tottime"). -t is ignored if this is set.')
@@ skipping 41 matching lines @@
   print('The extension documentation can be found at:')
   print('')
   print('  http://localhost:%s/extensions/' % opts.port)
   print('')
   print('The apps documentation can be found at:')
   print('')
   print('  http://localhost:%s/apps/' % opts.port)
   print('')
 
   logging.getLogger().setLevel(logging.INFO)
-  server = HTTPServer(('', int(opts.port)), _RequestHandler)
+  server = HTTPServer((opts.address, int(opts.port)), _RequestHandler)
   try:
     server.serve_forever()
   finally:
     server.socket.close()