Remove obsolete override "ios_extra_version_path".

ios/build/util/canary_version.py

-#!/usr/bin/env python
-# Copyright 2014 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.
-
-"""Writes canary version information to a specified file."""
-
-import datetime
-import sys
-import optparse
-import os
-
-
-def WriteIfChanged(file_name, content):
-  """
-  Write |content| to |file_name| iff the content is different from the
-  current content.
-  """
-  try:
-    old_content = open(file_name, 'rb').read()
-  except EnvironmentError:
-    pass
-  else:
-    if content == old_content:
-      return
-    os.unlink(file_name)
-  open(file_name, 'wb').write(content)
-
-
-def main(argv=None):
-  if argv is None:
-    argv = sys.argv
-
-  parser = optparse.OptionParser(usage="canary_version.py [options]")
-  parser.add_option("-o", "--output", metavar="FILE",
-                    help="write patch level to FILE")
-  opts, args = parser.parse_args(argv[1:])
-  out_file = opts.output
-
-  if args and out_file is None:
-    out_file = args.pop(0)
-
-  if args:
-    sys.stderr.write('Unexpected arguments: %r\n\n' % args)
-    parser.print_help()
-    sys.exit(2)
-
-  # Number of days since January 1st, 2012.
-  day_number = (datetime.date.today() - datetime.date(2012, 1, 1)).days
-  content = "PATCH={}\n".format(day_number)
-
-  if not out_file:
-    sys.stdout.write(content)
-  else:
-    WriteIfChanged(out_file, content)
-
-if __name__ == '__main__':
-  sys.exit(main())