switch to autox.py and robustify login/logout code

client/site_tests/desktopui_WindowManagerHotkeys/desktopui_WindowManagerHotkeys.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 os, random, time
 from autotest_lib.client.bin import site_ui_test, site_utils, test
 from autotest_lib.client.common_lib import error
 
 class desktopui_WindowManagerHotkeys(site_ui_test.UITest):
     version = 1
 
     def run_once(self):
-        import autox
-
-        # TODO: Set these in a single, standard place for all tests.
-        os.environ['DISPLAY'] = ':0'
-        os.environ['XAUTHORITY'] = '/home/chronos/.Xauthority'
-        ax = autox.AutoX()
+        ax = self.get_autox()
 
         # Start a terminal and wait for it to get the focus.
         # TODO: This is a bit of a hack.  To watch for the terminal getting
         # the focus, we create a new window, wait for it to get the focus,
         # and then launch the terminal and wait for our window to lose the
         # focus (AutoX isn't notified about focus events on the terminal
         # window itself).  It's maybe cleaner to add a method to AutoX to
         # get the currently-focused window and then just poll that after
         # starting the terminal until it changes.
         win = ax.create_and_map_window()
@@ skipping 19 matching lines @@
         # Press the Print Screen key and check that a screenshot is written.
         screenshot_filename = '/home/chronos/user/screenshot.png'
         if os.access(screenshot_filename, os.F_OK):
             os.remove(screenshot_filename)
         ax.send_hotkey('Print')
         site_utils.poll_for_condition(
             lambda: os.access(screenshot_filename, os.F_OK),
             error.TestFail(
                 'Waiting for screenshot at %s' % screenshot_filename))
         os.remove(screenshot_filename)