extensions: Introduce a fake ExtensionsClient implementation.

extensions/extensions.gyp

 # Copyright 2013 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': {
     'chromium_code': 1,
   },
   'targets': [
     {
       'target_name': 'extensions_common',
       'type': 'static_library',
       'dependencies': [
         'common/api/api.gyp:extensions_api',
         # TODO(benwells): figure out what to do with the api target and
         # api resources compiled into the chrome resource bundle.
         # http://crbug.com/162530
         '../chrome/chrome_resources.gyp:chrome_resources',
         # TODO(jamescook|derat): Pull strings into extensions module.
         '../chrome/chrome_resources.gyp:chrome_strings',
         # Need default icons in theme_resources.grd
         '../chrome/chrome_resources.gyp:theme_resources',
-        
+
         # TODO(tfarina): This dep here is for extensions/common/constants.*
         # We should find a way to compile this module within extensions_common.
         '../chrome/common_constants.gyp:common_constants',
         '../components/components.gyp:url_matcher',
         '../content/content.gyp:content_common',
         '../crypto/crypto.gyp:crypto',
         '../ipc/ipc.gyp:ipc',
         '../net/net.gyp:net',
         '../third_party/re2/re2.gyp:re2',
         '../ui/base/ui_base.gyp:ui_base',
@@ skipping 438 matching lines @@
         'common/file_util_unittest.cc',
         'common/id_util_unittest.cc',
         'common/manifest_handler_unittest.cc',
         'common/one_shot_event_unittest.cc',
         'common/permissions/api_permission_set_unittest.cc',
         'common/permissions/manifest_permission_set_unittest.cc',
         'common/url_pattern_set_unittest.cc',
         'common/url_pattern_unittest.cc',
         'common/user_script_unittest.cc',
         'test/extensions_unittests_main.cc',
+        'test/test_extensions_client.cc',
+        'test/test_extensions_client.h',
+        'test/test_permission_message_provider.cc',
+        'test/test_permission_message_provider.h',
+        'test/test_permissions_provider.cc',
+        'test/test_permissions_provider.h',
       ],
     },
   ]
 }