15 files declare their use of UrlGeneratorInterface in Drupal 8

BlockContentBlock.php in core/modules/block_content/src/Plugin/Block/BlockContentBlock.php

EntityController.php in core/lib/Drupal/Core/Entity/Controller/EntityController.php

EntityUrlTest.php in core/tests/Drupal/Tests/Core/Entity/EntityUrlTest.php

FormSubmitter.php in core/lib/Drupal/Core/Form/FormSubmitter.php

FormSubmitterTest.php in core/tests/Drupal/Tests/Core/Form/FormSubmitterTest.php

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

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

MetadataBubblingUrlGenerator.php in core/lib/Drupal/Core/Render/MetadataBubblingUrlGenerator.php

NodeTranslationExceptionSubscriber.php in core/modules/node/src/EventSubscriber/NodeTranslationExceptionSubscriber.php

PluginManager.php in core/modules/system/tests/modules/lazy_route_provider_install_test/src/PluginManager.php

RouterTest.php in core/tests/Drupal/Tests/Core/Routing/RouterTest.php

SupernovaGenerator.php in core/modules/help/tests/modules/help_test/src/SupernovaGenerator.php

TwigExtension.php in core/lib/Drupal/Core/Template/TwigExtension.php

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

ViewsForm.php in core/modules/views/src/Form/ViewsForm.php