[SyncFS] Implement MetadataDatabase initialization

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.
 {
   'targets': [
     {
       # This target contains mocks and test utilities that don't belong in
       # production libraries but are used by more than one test executable.
       'target_name': 'test_support_common',
       'type': 'static_library',
@@ skipping 1258 matching lines @@
         'browser/sync_file_system/drive_backend/drive_file_sync_service_fake_unittest.cc',
         'browser/sync_file_system/drive_backend/drive_file_sync_service_sync_unittest.cc',
         'browser/sync_file_system/drive_backend/drive_file_sync_service_unittest.cc',
         'browser/sync_file_system/drive_backend/drive_metadata_store_unittest.cc',
         'browser/sync_file_system/drive_backend/fake_api_util.cc',
         'browser/sync_file_system/drive_backend/fake_api_util.h',
         'browser/sync_file_system/drive_backend/fake_api_util_unittest.cc',
         'browser/sync_file_system/drive_backend/fake_drive_service_helper.cc',
         'browser/sync_file_system/drive_backend/fake_drive_service_helper.h',
         'browser/sync_file_system/drive_backend/local_sync_operation_resolver_unittest.cc',
+        'browser/sync_file_system/drive_backend/metadata_database_unittest.cc',
         'browser/sync_file_system/drive_backend/metadata_db_migration_util_unittest.cc',
         'browser/sync_file_system/drive_backend/remote_sync_operation_resolver_unittest.cc',
         'browser/sync_file_system/fake_remote_change_processor.cc',
         'browser/sync_file_system/fake_remote_change_processor.h',
         'browser/sync_file_system/local_file_sync_service_unittest.cc',
         'browser/sync_file_system/logger_unittest.cc',
         'browser/sync_file_system/mock_local_change_processor.cc',
         'browser/sync_file_system/mock_local_change_processor.h',
         'browser/sync_file_system/mock_remote_change_processor.cc',
         'browser/sync_file_system/mock_remote_change_processor.h',
@@ skipping 1353 matching lines @@
               # more details.
               'DebugInformationFormat': '3',
               'ProgramDataBaseFileName': '<(PRODUCT_DIR)/unit_tests.exe.pdb',
             },
           },
         },
       ],
     }],
   ],  # 'conditions'
 }