Introduce lock screen app context to extension features

tools/json_schema_compiler/feature_compiler.py

 # Copyright 2016 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 argparse
 import copy
 from datetime import datetime
 from functools import partial
 import os
 import re
@@ skipping 118 matching lines @@
     'component_extensions_auto_granted': {
       bool: {}
     },
     'contexts': {
       list: {
         'enum_map': {
           'blessed_extension': 'Feature::BLESSED_EXTENSION_CONTEXT',
           'blessed_web_page': 'Feature::BLESSED_WEB_PAGE_CONTEXT',
           'content_script': 'Feature::CONTENT_SCRIPT_CONTEXT',
           'extension_service_worker': 'Feature::SERVICE_WORKER_CONTEXT',
+          'lock_screen_extension': 'Feature::LOCK_SCREEN_EXTENSION_CONTEXT',
           'web_page': 'Feature::WEB_PAGE_CONTEXT',
           'webui': 'Feature::WEBUI_CONTEXT',
           'unblessed_extension': 'Feature::UNBLESSED_EXTENSION_CONTEXT',
         },
         'allow_all': True
       },
     },
     'default_parent': {
       bool: {'values': [True]}
     },
@@ skipping 627 matching lines @@
                       help='The source features.json files')
   args = parser.parse_args()
   if args.feature_type not in FEATURE_TYPES:
     raise NameError('Unknown feature type: %s' % args.feature_type)
   c = FeatureCompiler(args.chrome_root, args.source_files, args.feature_type,
                       args.provider_class, args.out_root,
                       args.out_base_filename)
   c.Load()
   c.Compile()
   c.Write()