Check for stray threads from tests and fail if found

testing_support/auto_stub.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.
 
 import collections
 import inspect
-import unittest
+
+from testing_support import thread_watcher
 
 
 class AutoStubMixIn(object):
   """Automatically restores stubbed functions on unit test teardDown.
 
   It's an extremely lightweight mocking class that doesn't require bookeeping.
   """
   _saved = None
 
   def mock(self, obj, member, mock):
@@ skipping 38 matching lines @@
 
   def _register_call(self, *args, **kwargs):
     """Registers the name of the caller function."""
     caller_name = kwargs.pop('caller_name', None) or inspect.stack()[1][3]
     str_args = ', '.join(repr(arg) for arg in args)
     str_kwargs = ', '.join('%s=%r' % (k, v) for k, v in kwargs.iteritems())
     self.calls.append('%s(%s)' % (
         caller_name, ', '.join(filter(None, [str_args, str_kwargs]))))
 
 
-class TestCase(unittest.TestCase, AutoStubMixIn):
+class TestCase(thread_watcher.TestCase, AutoStubMixIn):
   """Adds self.mock() and self.has_failed() to a TestCase."""
   def tearDown(self):
     AutoStubMixIn.tearDown(self)
-    unittest.TestCase.tearDown(self)
+    super(TestCase, self).tearDown()