6 files declare their use of StorageComparer

config.admin.inc in drupal/core/modules/config/config.admin.inc
Admin page callbacks for the config module.
config.inc in drupal/core/includes/config.inc
This is the API for configuration storage.
ConfigImporterTest.php in drupal/core/modules/config/lib/Drupal/config/Tests/ConfigImporterTest.php
Contains \Drupal\config\Tests\ConfigImporterTest.
ConfigSnapshotTest.php in drupal/core/modules/config/lib/Drupal/config/Tests/ConfigSnapshotTest.php
Contains \Drupal\config\Tests\ConfigSnapshotTest.
TestBase.php in drupal/core/modules/simpletest/lib/Drupal/simpletest/TestBase.php
Definition of Drupal\simpletest\TestBase.
ViewTestData.php in drupal/core/modules/views/lib/Drupal/views/Tests/ViewTestData.php
Contains \Drupal\views\Tests\ViewTestData.