Implement support for file: includes in OWNERS files.

testing_support/filesystem_mock.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 errno
 import fnmatch
 import os
 import re
 import StringIO
 
@@ skipping 20 matching lines @@
     return self._sep
 
   def _split(self, path):
     return path.rsplit(self.sep, 1)
 
   def abspath(self, path):
     if path.endswith(self.sep):
       return path[:-1]
     return path
 
+  def basename(self, path):
+    if self.sep not in path:
+      return ''
+    return self._split(path)[-1] or self.sep
+
   def dirname(self, path):
     if self.sep not in path:
       return ''
     return self._split(path)[0] or self.sep
 
   def exists(self, path):
     return self.isfile(path) or self.isdir(path)
 
   def isabs(self, path):
     return path.startswith(self.sep)
@@ skipping 29 matching lines @@
     if self.files[path] is None:
       _RaiseNotFound(path)
     return self.files[path]
 
   @staticmethod
   def relpath(path, base):
     # This implementation is wrong in many ways; assert to check them for now.
     assert path.startswith(base)
     assert base.endswith('/')
     return path[len(base):]