26 files declare their use of LockBackendInterface in Drupal 8

AliasWhitelist.php in core/lib/Drupal/Core/Path/AliasWhitelist.php

BlockContentUuidLookup.php in core/modules/block_content/src/BlockContentUuidLookup.php

CacheCollector.php in core/lib/Drupal/Core/Cache/CacheCollector.php

ConfigImporter.php in core/lib/Drupal/Core/Config/ConfigImporter.php

ConfigSingleImportForm.php in core/modules/config/src/Form/ConfigSingleImportForm.php

ConfigSync.php in core/modules/config/src/Form/ConfigSync.php

Cron.php in core/lib/Drupal/Core/Cron.php

DeprecatedClassesTest.php in core/modules/path_alias/tests/src/Unit/DeprecatedClassesTest.php

ExportStorageManager.php in core/lib/Drupal/Core/Config/ExportStorageManager.php

FileUploadResource.php in core/modules/file/src/Plugin/rest/resource/FileUploadResource.php

ImageStyleDownloadController.php in core/modules/image/src/Controller/ImageStyleDownloadController.php

ImportStorageTransformer.php in core/lib/Drupal/Core/Config/ImportStorageTransformer.php

LibraryDiscoveryCollector.php in core/lib/Drupal/Core/Asset/LibraryDiscoveryCollector.php

LocaleLookup.php in core/modules/locale/src/LocaleLookup.php

LocaleTranslation.php in core/modules/locale/src/LocaleTranslation.php

MenuActiveTrail.php in core/lib/Drupal/Core/Menu/MenuActiveTrail.php

MenuRouterRebuildSubscriber.php in core/lib/Drupal/Core/EventSubscriber/MenuRouterRebuildSubscriber.php

PrivateTempStore.php in core/lib/Drupal/Core/TempStore/PrivateTempStore.php

PrivateTempStoreFactory.php in core/lib/Drupal/Core/TempStore/PrivateTempStoreFactory.php

Registry.php in core/lib/Drupal/Core/Theme/Registry.php

RouteBuilder.php in core/lib/Drupal/Core/Routing/RouteBuilder.php

SharedTempStore.php in core/lib/Drupal/Core/TempStore/SharedTempStore.php

SharedTempStoreFactory.php in core/lib/Drupal/Core/TempStore/SharedTempStoreFactory.php

SystemTestController.php in core/modules/system/tests/modules/system_test/src/Controller/SystemTestController.php

TemporaryJsonapiFileFieldUploader.php in core/modules/jsonapi/src/Controller/TemporaryJsonapiFileFieldUploader.php

ThemeRegistry.php in core/lib/Drupal/Core/Utility/ThemeRegistry.php