The password manager python tests now logout from websites by cleaning the cookies.

components/test/data/password_manager/environment.py

 # 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.
 
 """The testing Environment class."""
 
 import logging
 import shutil
 import sys
 import time
@@ skipping 154 matching lines @@
     else:
       self.working_tests.append(websitetest.name)
 
   def RemoveAllPasswords(self):
     """Removes all the stored passwords."""
     logging.info("\nRemoveAllPasswords\n")
     self.driver.get("chrome://settings/passwords")
     self.driver.switch_to_frame("settings")
     while True:
       try:
-        self.driver.execute_script("document.querySelector('"
-          "#saved-passwords-list .row-delete-button').click()")
+        self.driver.execute_script(
+            "document.querySelector('#saved-passwords-list .row-delete-button')"
+            ".click()")
         time.sleep(1)
       except NoSuchElementException:
         break
       except WebDriverException:
         break
 
+  def ClearAllCookies(self):
+    """Removes all the cookies."""
+    logging.info("\nClearAllCookies\n")
+    self.driver.get("chrome://settings/clearBrowserData")
+    self.driver.switch_to_frame("settings")
+    self.driver.execute_script(
+        "var checkboxes = document.querySelectorAll("
+        "    '#clear-data-checkboxes [type=\\\'checkbox\\\']');"
+        "for (var i in checkboxes)"
+        "    checkboxes[i].checked = false;"
+        "document.querySelector('#delete-cookies-checkbox').checked = true;"
+        "document.querySelector('#clear-browser-data-commit').click();")
+    time.sleep(2)
+
   def OpenTabAndGoToInternals(self, url):
     """If there is no |self.website_window|, opens a new tab and navigates to
     |url| in the new tab. Navigates to the passwords internals page in the
     first tab. Raises an exception otherwise.
 
     Args:
       url: Url to go to in the new tab.
 
     Raises:
       Exception: An exception is raised if |self.website_window| already
@@ skipping 194 matching lines @@
       except Exception:
         successful = False
         error = traceback.format_exc()
       self.tests_results.append(TestResult(websitetest.name, "prompt",
           successful, escape(error)))
 
   def Quit(self):
     """Closes the tests."""
     # Close the webdriver.
     self.driver.quit()