switch to autox.py and robustify login/logout code

client/common_lib/site_ui.py

 # Copyright (c) 2010 The Chromium OS 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 logging, shutil
+import logging, os, shutil
 from autotest_lib.client.common_lib import site_httpd, utils
 
 
 def xcommand(cmd):
     """
     Add the necessary X setup to a shell command that needs to connect to the X
     server.
 
     @param cmd: the command line string
     @return a modified command line string with necessary X setup
@@ skipping 21 matching lines @@
 def xsystem_as(cmd, user='chronos', timeout=None, ignore_status=False):
     """
     Run the command cmd as the given user, using utils.system, after adding
     the necessary setup to connect to the X server.
     """
 
     return utils.system(xcommand_as(cmd, user=user), timeout=timeout,
                         ignore_status=ignore_status)
 
 
+def get_autox():
+    """Return a new autox instance."""
+    # we're running as root, but need to connect to chronos' X session
+    os.environ.setdefault('XAUTHORITY', '/home/chronos/.Xauthority')
+    os.environ.setdefault('DISPLAY', ':0.0')
+
+    import autox
+    return autox.AutoX()
+
+
 class ChromeSession(object):
     """
     A class to start and close Chrome sessions.
     """
 
     def __init__(self, args='', clean_state=True, suid=True):
         self._clean_state = clean_state
         self.start(args, suid=suid)
 
 
@@ skipping 88 matching lines @@
             http_server.stop()
 
         # Return None if timeout.
         if not latch.is_set():
             http_server.stop()
             return None
 
         result = http_server.get_form_entries()['result']
         http_server.stop()
         return result