Add policy provider that would filter extensions/apps allowed on the

chrome/chrome_browser_chromeos.gypi

 # 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.
 
 {
   'variables': {
     # These files lists are shared with the GN build.
     'browser_chromeos_sources': [
         # All .cc, .h, .m, and .mm files under browser/chromeos, except for tests
@@ skipping 210 matching lines @@
         'browser/chromeos/extensions/input_method_event_router.cc',
         'browser/chromeos/extensions/input_method_event_router.h',
         'browser/chromeos/extensions/install_limiter.cc',
         'browser/chromeos/extensions/install_limiter.h',
         'browser/chromeos/extensions/install_limiter_factory.cc',
         'browser/chromeos/extensions/install_limiter_factory.h',
         'browser/chromeos/extensions/launcher_search_provider.cc',
         'browser/chromeos/extensions/launcher_search_provider.h',
         'browser/chromeos/extensions/media_player_event_router.cc',
         'browser/chromeos/extensions/media_player_event_router.h',
+        'browser/chromeos/extensions/signin_screen_policy_provider.cc',
+        'browser/chromeos/extensions/signin_screen_policy_provider.h',
         'browser/chromeos/external_metrics.cc',
         'browser/chromeos/external_metrics.h',
         'browser/chromeos/external_protocol_dialog.cc',
         'browser/chromeos/external_protocol_dialog.h',
         'browser/chromeos/feedback_util.cc',
         'browser/chromeos/feedback_util.h',
         'browser/chromeos/file_manager/app_id.h',
         'browser/chromeos/file_manager/arc_file_tasks.cc',
         'browser/chromeos/file_manager/arc_file_tasks.h',
         'browser/chromeos/file_manager/file_browser_handlers.cc',
@@ skipping 1140 matching lines @@
         'browser/chromeos/attestation/attestation_signed_data.proto',
       ],
       'variables': {
         'proto_in_dir': 'browser/chromeos/attestation',
         'proto_out_dir': 'chrome/browser/chromeos/attestation',
       },
       'includes': [ '../build/protoc.gypi' ]
     },
   ],
 }