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

checkout.py

 # coding=utf8
 # 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.
 """Manages a project checkout.
 
 Includes support for svn, git-svn and git.
 """
 
 import ConfigParser
@@ skipping 325 matching lines @@
                 raise PatchApplicationFailed(
                     p,
                     'File has a source filename specified but is not new')
               # Copy the file first.
               if os.path.isfile(filepath):
                 raise PatchApplicationFailed(
                     p, 'File exist but was about to be overwriten')
               self._check_output_svn(
                   ['copy', p.source_filename, p.filename])
             if p.diff_hunks:
-              cmd = ['patch', '-p%s' % p.patchlevel, '--forward', '--force']
+              cmd = [
+                'patch',
+                '-p%s' % p.patchlevel,
+                '--forward',
+                '--force',
+                '--no-backup-if-mismatch',
+              ]
               stdout += subprocess2.check_output(
                   cmd, stdin=p.get(False), cwd=self.project_path)
             elif p.is_new and not os.path.exists(filepath):
               # There is only a header. Just create the file if it doesn't
               # exist.
               open(filepath, 'w').close()
           if p.is_new and not p.source_filename:
             # Do not run it if p.source_filename is defined, since svn copy was
             # using above.
             stdout += self._check_output_svn(
@@ skipping 292 matching lines @@
   def revisions(self, rev1, rev2):
     return self.checkout.revisions(rev1, rev2)
 
   @property
   def project_name(self):
     return self.checkout.project_name
 
   @property
   def project_path(self):
     return self.checkout.project_path