Actually call the NormlizeFilePath function for download platform detection.

download_from_google_storage.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.
 
 """Download files from Google Storage based on SHA1 sums."""
 
 
 import hashlib
 import optparse
@@ skipping 315 matching lines @@
                     help='A regular expression that is compared against '
                          'Python\'s sys.platform. If this option is specified, '
                          'the download will happen only if there is a match.')
   parser.add_option('-v', '--verbose', action='store_true',
                     help='Output extra diagnostic and progress information.')
 
   (options, args) = parser.parse_args()
 
   # Make sure we should run at all based on platform matching.
   if options.platform:
-    if not re.match(options.platform, sys.platform):
+    if not re.match(options.platform, GetNormalizedPlatform()):
       if options.verbose:
         print('The current platform doesn\'t match "%s", skipping.' %
               options.platform)
       return 0
 
   # Set the boto file to /dev/null if we don't need auth.
   if options.no_auth:
     options.boto = os.devnull
 
   # Make sure we can find a working instance of gsutil.
@@ skipping 55 matching lines @@
     return code
 
   return download_from_google_storage(
       input_filename, base_url, gsutil, options.num_threads, options.directory,
       options.recursive, options.force, options.output, options.ignore_errors,
       options.sha1_file, options.verbose)
 
 
 if __name__ == '__main__':
   sys.exit(main(sys.argv))