Some test code in components/drive is built as part of unit_tests, not as part of components_unittests because of dependencies to //chrome needed by the tests.
These //chrome dependencies should be removed from the test .cc files, and the .cc files should be listed in components/drive/BUILD.gn and built as part of components_unittests.

List of test .cc files in components/drive which are currently built as part of unit_tests.

  In chrome/test/BUILD.gn:
    "../../components/drive/drive_api_util_unittest.cc",
    "../../components/drive/drive_app_registry_unittest.cc",
    "../../components/drive/drive_uploader_unittest.cc",
    "../../components/drive/event_logger_unittest.cc",
    "../../components/drive/service/drive_api_service_unittest.cc",
    "../../components/drive/service/fake_drive_service_unittest.cc",

  In chrome/browser/chromeos/BUILD.gn
    "//components/drive/change_list_loader_unittest.cc",
    "//components/drive/change_list_processor_unittest.cc",
    "//components/drive/chromeos/file_cache_unittest.cc",
    "//components/drive/directory_loader_unittest.cc",
    "//components/drive/fake_file_system_unittest.cc",
    "//components/drive/file_change_unittest.cc",
    "//components/drive/file_system/copy_operation_unittest.cc",
    "//components/drive/file_system/create_directory_operation_unittest.cc",
    "//components/drive/file_system/create_file_operation_unittest.cc",
    "//components/drive/file_system/download_operation_unittest.cc",
    "//components/drive/file_system/get_file_for_saving_operation_unittest.cc",
    "//components/drive/file_system/move_operation_unittest.cc",
    "//components/drive/file_system/open_file_operation_unittest.cc",
    "//components/drive/file_system/operation_test_base.cc",
    "//components/drive/file_system/operation_test_base.h",
    "//components/drive/file_system/remove_operation_unittest.cc",
    "//components/drive/file_system/search_operation_unittest.cc",
    "//components/drive/file_system/set_property_operation_unittest.cc",
    "//components/drive/file_system/touch_operation_unittest.cc",
    "//components/drive/file_system/truncate_operation_unittest.cc",
    "//components/drive/file_system_core_util_unittest.cc",
    "//components/drive/file_system_unittest.cc",
    "//components/drive/file_write_watcher_unittest.cc",
    "//components/drive/job_queue_unittest.cc",
    "//components/drive/job_scheduler_unittest.cc",
    "//components/drive/local_file_reader_unittest.cc",
    "//components/drive/remove_stale_cache_files_unittest.cc",
    "//components/drive/resource_entry_conversion_unittest.cc",
    "//components/drive/resource_metadata_storage_unittest.cc",
    "//components/drive/resource_metadata_unittest.cc",
    "//components/drive/search_metadata_unittest.cc",
    "//components/drive/sync/entry_revert_performer_unittest.cc",
    "//components/drive/sync/entry_update_performer_unittest.cc",
    "//components/drive/sync/remove_performer_unittest.cc",
    "//components/drive/sync_client_unittest.cc",