Add ChromeVox panel and implement caption display functionality.

chrome/browser/resources/chromeos/chromevox/tools/generate_manifest.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.
 
 import json
 import io
 import optparse
 import os
@@ skipping 39 matching lines @@
   parser.add_option(
       '-o', '--output_manifest', action='store', metavar='OUTPUT_MANIFEST',
       help='File to place generated manifest')
   parser.add_option(
       '--is_guest_manifest', default='0', action='store', metavar='NUM',
       help='Whether to generate a guest mode capable manifest')
   parser.add_option(
       '--is_chromevox_classic', default='0', action='store', metavar='NUM',
       help='Whether to generate a ChromeVox Classic manifest')
   parser.add_option(
+      '--is_chromeos', default='0', action='store', metavar='NUM',
+      help='Whether to add permissions specific to Chrome OS')
+  parser.add_option(
       '--is_js_compressed', default='1', action='store', metavar='NUM',
       help='Whether compressed JavaScript files are used')
   parser.add_option(
       '--set_version', action='store', metavar='SET_VERSION',
       help='Set the extension version')
   parser.add_option(
       '--key', action='store', metavar='KEY',
       help='Set the extension key')
   parser.add_option(
       '--version_file', action='store', metavar='NAME',
@@ skipping 13 matching lines @@
     print >>sys.stderr, ('one of --set_version or --version_file option ' +
         'must be specified')
     sys.exit(1)
   context = {k: v for k, v in parser.values.__dict__.items() if v is not None}
   if options.version_file is not None:
     context['set_version'] = getChromeVersion(options.version_file)
   processJinjaTemplate(args[0], options.output_manifest, context)
 
 if __name__ == '__main__':
   main()