Move extension_test_message_listener to extensions.

chrome/chrome_tests_unit.gypi

 # Copyright 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': {
     'chrome_unit_tests_sources': [
       '../apps/app_shim/app_shim_host_mac_unittest.cc',
       '../apps/app_shim/extension_app_shim_handler_mac_unittest.cc',
       '../apps/saved_files_service_unittest.cc',
       '../components/autofill/content/renderer/test_password_autofill_agent.cc',
@@ skipping 1780 matching lines @@
             'browser/drive/dummy_drive_service.cc',
             'browser/drive/dummy_drive_service.h',
             'browser/drive/fake_drive_service.cc',
             'browser/drive/fake_drive_service.h',
             'browser/drive/test_util.cc',
             'browser/drive/test_util.h',
             'browser/extensions/api/messaging/native_messaging_test_util.cc',
             'browser/extensions/api/messaging/native_messaging_test_util.h',
             'browser/extensions/extension_notification_observer.cc',
             'browser/extensions/extension_notification_observer.h',
-            'browser/extensions/extension_test_message_listener.cc',
-            'browser/extensions/extension_test_message_listener.h',
             'browser/extensions/mock_extension_special_storage_policy.cc',
             'browser/extensions/mock_extension_special_storage_policy.h',
             'browser/extensions/test_blacklist.cc',
             'browser/extensions/test_blacklist.h',
             'browser/extensions/test_blacklist_state_fetcher.cc',
             'browser/extensions/test_blacklist_state_fetcher.h',
             'browser/extensions/test_extension_environment.cc',
             'browser/extensions/test_extension_environment.h',
             'browser/extensions/test_extension_prefs.cc',
             'browser/extensions/test_extension_prefs.h',
@@ skipping 1064 matching lines @@
               'dependencies': [
                 '../tools/xdisplaycheck/xdisplaycheck.gyp:xdisplaycheck',
               ],
             }],
           ],
         },
       ],
     }],
   ],  # 'conditions'
 }