Enforce the 'requirements' field in manifests.

chrome/chrome_browser_extensions.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.
 
 {
   'targets': [
     {
       'target_name': 'browser_extensions',
       'type': 'static_library',
       'variables': { 'enable_wexit_time_destructors': 1, },
@@ skipping 430 matching lines @@
         'browser/extensions/platform_app_launcher.cc',
         'browser/extensions/platform_app_launcher.h',
         'browser/extensions/pending_extension_info.cc',
         'browser/extensions/pending_extension_info.h',
         'browser/extensions/pending_extension_manager.cc',
         'browser/extensions/pending_extension_manager.h',
         'browser/extensions/permissions_updater.cc',
         'browser/extensions/permissions_updater.h',
         'browser/extensions/process_map.cc',
         'browser/extensions/process_map.h',
+        'browser/extensions/requirements_provider.cc',
+        'browser/extensions/requirements_provider.h',
         'browser/extensions/sandboxed_unpacker.cc',
         'browser/extensions/sandboxed_unpacker.h',
         'browser/extensions/script_badge_controller.cc',
         'browser/extensions/script_badge_controller.h',
         'browser/extensions/script_executor.cc',
         'browser/extensions/script_executor.h',
         'browser/extensions/settings/leveldb_settings_storage_factory.cc',
         'browser/extensions/settings/leveldb_settings_storage_factory.h',
         'browser/extensions/settings/setting_sync_data.cc',
         'browser/extensions/settings/setting_sync_data.h',
@@ skipping 253 matching lines @@
             'browser/extensions/extension_tab_util.cc',
             'browser/extensions/platform_app_launcher.cc',
             'browser/extensions/platform_app_launcher.h',
           ],
         }],
       ],
     },
   ],
 }