Introduce lock screen app context to extension features

tools/json_schema_compiler/feature_compiler_test.py

 #!/usr/bin/env python
 # Copyright 2015 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 copy
 import feature_compiler
 import unittest
 
 class FeatureCompilerTest(unittest.TestCase):
@@ skipping 24 matching lines @@
     feature_compiler.ENABLE_ASSERTIONS = False
     feature_compiler.STRINGS_TO_UNICODE = True
 
   def testFeature(self):
     # Test some basic feature parsing for a sanity check.
     f = self._parseFeature({
       'blacklist': ['aaa', 'bbb'],
       'channel': 'stable',
       'command_line_switch': 'switch',
       'component_extensions_auto_granted': False,
-      'contexts': ['blessed_extension', 'blessed_web_page'],
+      'contexts': [
+        'blessed_extension',
+        'blessed_web_page',
+        'lock_screen_extension'
+      ],
       'default_parent': True,
       'dependencies': ['dependency1', 'dependency2'],
       'extension_types': ['extension'],
       'location': 'component',
       'internal': True,
       'matches': ['*://*/*'],
       'max_manifest_version': 1,
       'noparent': True,
       'platforms': ['mac', 'win'],
       'session_types': ['kiosk', 'regular'],
@@ skipping 282 matching lines @@
           'channel': 'stable',
           'contexts': ['webui'],
         }])
 
     with self.assertRaisesRegexp(AssertionError,
                                  'No default parent found for bookmarks'):
       c._CompileFeature('bookmarks.export', { "whitelist": ["asdf"] })
 
 if __name__ == '__main__':
   unittest.main()