16 files declare their use of ModuleHandlerInterface

ActionListController.php in drupal/core/modules/action/lib/Drupal/action/ActionListController.php
Contains \Drupal\action\ActionListController.
AdminController.php in drupal/core/modules/system/lib/Drupal/system/Controller/AdminController.php
Contains \Drupal\system\Controller\AdminController.
AggregatorController.php in drupal/core/modules/aggregator/lib/Drupal/aggregator/Controller/AggregatorController.php
Contains \Drupal\aggregator\Controller\AggregatorController.
Analyzer.php in drupal/core/modules/views/lib/Drupal/views/Analyzer.php
Contains \Drupal\views\Analyzer.
CountryManager.php in drupal/core/lib/Drupal/Core/Locale/CountryManager.php
Definition of \Drupal\Core\Locale\CountryManager.
DbLogController.php in drupal/core/modules/dblog/lib/Drupal/dblog/Controller/DbLogController.php
Contains \Drupal\dblog\Controller\DbLogController.
EntityListController.php in drupal/core/lib/Drupal/Core/Entity/EntityListController.php
Contains \Drupal\Core\Entity\EntityListController.
FieldInfo.php in drupal/core/modules/field/lib/Drupal/field/FieldInfo.php
Contains \Drupal\field\FieldInfo.
HelpController.php in drupal/core/modules/help/lib/Drupal/help/Controller/HelpController.php
Contains \Drupal\help\Controller\HelpController.
RequestCloseSubscriber.php in drupal/core/lib/Drupal/Core/EventSubscriber/RequestCloseSubscriber.php
Definition of Drupal\Core\EventSubscriber\RequestCloseSubscriber.
RouteBuilder.php in drupal/core/lib/Drupal/Core/Routing/RouteBuilder.php
Definition of Drupal\Core\Routing\RouteBuilder.
SetDelete.php in drupal/core/modules/shortcut/lib/Drupal/shortcut/Form/SetDelete.php
Contains \Drupal\shortcut\Form\SetDelete.
SystemManager.php in drupal/core/modules/system/lib/Drupal/system/SystemManager.php
Contains \Drupal\system\SystemManager.
Token.php in drupal/core/lib/Drupal/Core/Utility/Token.php
Definition of Drupal\Core\Utility\Token.
UpdateController.php in drupal/core/modules/update/lib/Drupal/update/Controller/UpdateController.php
Contains \Drupal\update\Controller\UpdateController.
ViewsData.php in drupal/core/modules/views/lib/Drupal/views/ViewsData.php
Contains \Drupal\views\ViewsData.