[Sync] Remove unused mock_gaia_authenticator* files

chrome/chrome_tests.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' : {
     'pyautolib_sources': [
       'app/chrome_command_ids.h',
       'app/chrome_dll_resource.h',
       'common/automation_constants.h',
       'common/pref_names.cc',
@@ skipping 3638 matching lines @@
         'browser/sync/syncable/model_type_unittest.cc',
         'browser/sync/syncable/syncable_enum_conversions_unittest.cc',
         'browser/sync/syncable/syncable_id_unittest.cc',
         'browser/sync/syncable/syncable_unittest.cc',
         'browser/sync/test/engine/fake_model_safe_worker_registrar.cc',
         'browser/sync/test/engine/fake_model_safe_worker_registrar.h',
         'browser/sync/test/engine/fake_model_worker.cc',
         'browser/sync/test/engine/fake_model_worker.h',
         'browser/sync/test/engine/mock_connection_manager.cc',
         'browser/sync/test/engine/mock_connection_manager.h',
-        'browser/sync/test/engine/mock_gaia_authenticator.cc',
-        'browser/sync/test/engine/mock_gaia_authenticator.h',
-        'browser/sync/test/engine/mock_gaia_authenticator_unittest.cc',
         'browser/sync/test/engine/syncer_command_test.cc',
         'browser/sync/test/engine/syncer_command_test.h',
         'browser/sync/test/engine/test_id_factory.h',
         'browser/sync/test/engine/test_syncable_utils.cc',
         'browser/sync/test/engine/test_syncable_utils.h',
         'browser/sync/test/sessions/test_scoped_session_event_listener.h',
         'browser/sync/util/cryptographer_unittest.cc',
         'browser/sync/util/data_encryption_unittest.cc',
         'browser/sync/util/data_type_histogram_unittest.cc',
         'browser/sync/util/enum_set_unittest.cc',
@@ skipping 1038 matching lines @@
               # Use outputs of this action as inputs for the main target build.
               # Seems as a misnomer but makes this happy on Linux (scons).
               'process_outputs_as_sources': 1,
             },
           ],  # 'actions'
         },
       ]
     }],  # 'coverage!=0'
   ],  # 'conditions'
 }