Fix depot_tools presubmit check for ubuntu 12.04.

testing_support/super_mox.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.
 
 """Simplify unit tests based on pymox."""
 
 import os
 import random
 import shutil
 import string
@@ skipping 80 matching lines @@
     # Override the mock with a StringIO, it's much less painful to test.
     self._old_stdout = sys.stdout
     stdout = StringIO.StringIO()
     stdout.flush = lambda: None
     sys.stdout = stdout
 
   def tearDown(self):
     try:
       # If sys.stdout was used, self.checkstdout() must be called.
       # pylint: disable=E1101
-      self.assertEquals('', sys.stdout.getvalue())
+      if not sys.stdout.closed:
+        self.assertEquals('', sys.stdout.getvalue())
     except AttributeError:
       pass
     sys.stdout = self._old_stdout
 
   def checkstdout(self, expected):
     value = sys.stdout.getvalue()
     sys.stdout.close()
     # pylint: disable=E1101
     self.assertEquals(expected, value)
 
@@ skipping 33 matching lines @@
         except TypeError, e:
           raise TypeError(
               'Couldn\'t mock %s in %s: %s' % (item, parent.__name__, e))
 
   def UnMock(self, obj, name):
     """Restore an object inside a test."""
     for (parent, old_child, child_name) in self.mox.stubs.cache:
       if parent == obj and child_name == name:
         setattr(parent, child_name, old_child)
         break