Add --no-backup-if-mismatch so no .orig file is created when fuzzing occurs.

tests/checkout_test.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.
 
 """Unit tests for checkout.py."""
 
 import logging
 import os
 import shutil
@@ skipping 289 matching lines @@
     expected = {
         'author': self.FAKE_REPOS.USERS[0][0],
         'revprops': [('realauthor', self.FAKE_REPOS.USERS[1][0])]
     }
     root = os.path.join(self.root_dir, self.name)
     self._check_base(self._get_co(None), root, False, expected)
 
   def testException(self):
     self._check_exception(
         self._get_co(None),
-        'While running patch -p1 --forward --force;\n'
+        'While running patch -p1 --forward --force --no-backup-if-mismatch;\n'
         'patching file chrome/file.cc\n'
         'Hunk #1 FAILED at 3.\n'
         '1 out of 1 hunk FAILED -- saving rejects to file '
         'chrome/file.cc.rej\n')
 
   def testSvnProps(self):
     co = self._get_co(None)
     co.prepare(None)
     try:
       # svn:ignore can only be applied to directories.
@@ skipping 185 matching lines @@
             self.root_dir, self.name, None, None, self.svn_url, None),
         post_processors)
 
   def testAll(self):
     root = os.path.join(self.root_dir, self.name)
     self._check_base(self._get_co(None), root, False, None)
 
   def testException(self):
     self._check_exception(
         self._get_co(None),
-        'While running patch -p1 --forward --force;\n'
+        'While running patch -p1 --forward --force --no-backup-if-mismatch;\n'
         'patching file chrome/file.cc\n'
         'Hunk #1 FAILED at 3.\n'
         '1 out of 1 hunk FAILED -- saving rejects to file '
         'chrome/file.cc.rej\n')
 
   def testProcess(self):
     self._test_process(self._get_co)
 
   def testPrepare(self):
     self._test_prepare(self._get_co(None))
 
   def testMove(self):
     self._check_move(self._get_co(None))
 
 
 if __name__ == '__main__':
   if '-v' in sys.argv:
     DEBUGGING = True
     logging.basicConfig(
         level=logging.DEBUG,
         format='%(levelname)5s %(filename)15s(%(lineno)3d): %(message)s')
   else:
     logging.basicConfig(
         level=logging.ERROR,
         format='%(levelname)5s %(filename)15s(%(lineno)3d): %(message)s')
   unittest.main()