First pass at refactoring pyautolib in preparation for removing proxy dependencies.

chrome/test/functional/test_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.
 
 import unittest
 
 import pyauto_functional  # Must be imported before pyauto
 import pyauto
 import pyauto_errors
@@ skipping 24 matching lines @@
       self.assertEqual(self.FindInPage(flag)['match_count'], 1,
                        msg='Missing expected Chrome flag "%s"' % flag)
 
   def testCallOnInvalidWindow(self):
     """Verify that exception is raised when a browser is missing/invalid."""
     self.assertEqual(1, self.GetBrowserWindowCount())
     self.assertRaises(
         pyauto_errors.JSONInterfaceError,
         lambda: self.FindInPage('some text', windex=1))  # invalid window
 
+  def testJSONInterfaceTimeout(self):
+    """Verify that an exception is raised when the JSON interface times out."""
+    self.ClearEventQueue()
+    self.AddDomEventObserver('foo')
+    self.assertRaises(
+        pyauto_errors.JSONInterfaceError,
+        lambda: self.GetNextEvent(timeout=2000))  # event queue is empty
+
+
 
 if __name__ == '__main__':
   pyauto_functional.Main()