[cros] Fix tests: Reach the "Add user" screen before attempting to login

chrome/test/pyautolib/pyauto.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.
 
 """PyAuto: Python Interface to Chromium's Automation Proxy.
 
 PyAuto uses swig to expose Automation Proxy interfaces to Python.
 For complete documentation on the functionality available,
 run pydoc on this file.
@@ skipping 4585 matching lines @@
     will not be noticed here, because the browser has no knowledge of it. In
     this case the GetNextEvent automation command will always time out.
 
     Returns:
       An error string if an error occured.
       None otherwise.
 
     Raises:
       pyauto_errors.JSONInterfaceError if the automation call returns an error.
     """
+    # Go to the 'Add user' screen for login to work.
+    self.ExecuteJavascriptInOOBEWebUI(
+              'Oobe.showSigninUI();'
+              'window.domAutomationController.send("ok");')
     self._GetResultFromJSONRequest({'command': 'AddLoginEventObserver'},
                                    windex=None)
     cmd_dict = {
         'command': 'SubmitLoginForm',
         'username': username,
         'password': password,
     }
     self._GetResultFromJSONRequest(cmd_dict, windex=None)
     try:
       # TODO(craigdh): Add login failure events once PyAuto switches to mocked
@@ skipping 1743 matching lines @@
     successful = result.wasSuccessful()
     if not successful:
       pyauto_tests_file = os.path.join(self.TestsDir(), self._tests_filename)
       print >>sys.stderr, 'Tests can be disabled by editing %s. ' \
                           'Ref: %s' % (pyauto_tests_file, _PYAUTO_DOC_URL)
     sys.exit(not successful)
 
 
 if __name__ == '__main__':
   Main()