implement per-file OWNERS support

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
 
 
 def _RaiseNotFound(path):
   raise IOError(errno.ENOENT, path, os.strerror(errno.ENOENT))
 
 
 class MockFileSystem(object):
@@ skipping 42 matching lines @@
     # to a different thread and potentially modifying the dict in
     # mid-iteration.
     files = self.files.keys()[:]
     return any(f.startswith(path) for f in files)
 
   def join(self, *comps):
     # TODO: Might want tests for this and/or a better comment about how
     # it works.
     return re.sub(re.escape(os.path.sep), self.sep, os.path.join(*comps))
 
+  def glob(self, path):
+    return fnmatch.filter(self.files.keys(), path)
+
   def open_for_reading(self, path):
     return StringIO.StringIO(self.read_binary_file(path))
 
   def read_binary_file(self, path):
     # Intentionally raises KeyError if we don't recognize the path.
     if self.files[path] is None:
       _RaiseNotFound(path)
     return self.files[path]
+
+  @staticmethod
+  def relpath(base, path):
+    if path.startswith(base):
+      return path[len(base):]
+    return path