Allow chromedriver to set local state preferences.

chrome/test/pyautolib/chrome_driver_factory.py

 # Copyright (c) 2011 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.
 
 """Factory that creates ChromeDriver instances for pyauto."""
 
 import os
 import random
 import tempfile
 
@@ skipping 23 matching lines @@
 
     Returns:
       selenium.webdriver.remote.webdriver.WebDriver instance.
     """
     self._StartServerIfNecessary()
     channel_id = 'testing' + hex(random.getrandbits(20 * 4))[2:-1]
     if not pyauto.IsWin():
       channel_id = os.path.join(tempfile.gettempdir(), channel_id)
     pyauto.CreateNewAutomationProvider(channel_id)
     return webdriver.Remote(self._chromedriver_server.service_url,
-                            {'chrome.channel': channel_id})
+                            {'chrome.channel': channel_id,
+                             'chrome.noWebsiteTestingDefaults': True})
 
   def _StartServerIfNecessary(self):
     """Starts the ChromeDriver server, if not already started."""
     if self._chromedriver_server is None:
       exe = pyauto_paths.GetChromeDriverExe()
       assert exe, 'Cannot find chromedriver exe. Did you build it?'
       self._chromedriver_server = service.Service(exe)
       self._chromedriver_server.start()
 
   def Stop(self):
     """Stops the ChromeDriver server, if running."""
     if self._chromedriver_server is not None:
       self._chromedriver_server.stop()
       self._chromedriver_server = None
 
   def __del__(self):
     self.Stop()