8 files declare their use of EntityManagerInterface in Drupal 8

BundleConfigImportValidate.php in core/lib/Drupal/Core/Entity/Event/BundleConfigImportValidate.php

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

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

EntityConverter.php in core/lib/Drupal/Core/ParamConverter/EntityConverter.php

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

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

Contains \Drupal\Tests\Core\Entity\EntityTypeManagerTest.

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

SelectionTrait.php in core/lib/Drupal/Core/Entity/EntityReferenceSelection/SelectionTrait.php