25 files declare their use of ThemeHandlerInterface in Zircon Profile 8

BasicSettingsForm.php in core/modules/views_ui/src/Form/BasicSettingsForm.php

Contains \Drupal\views_ui\Form\BasicSettingsForm.

BlockContentController.php in core/modules/block_content/src/Controller/BlockContentController.php

Contains \Drupal\block_content\Controller\BlockContentController.

BlockController.php in core/modules/block/src/Controller/BlockController.php

Contains \Drupal\block\Controller\BlockController.

BlockForm.php in core/modules/block/src/BlockForm.php

Contains \Drupal\block\BlockForm.

BlockListController.php in core/modules/block/src/Controller/BlockListController.php

Contains \Drupal\block\Controller\BlockListController.

BreakpointManager.php in core/modules/breakpoint/src/BreakpointManager.php

Contains \Drupal\breakpoint\BreakpointManager.

ConfigCacheTag.php in core/modules/system/src/EventSubscriber/ConfigCacheTag.php

Contains \Drupal\system\EventSubscriber\ConfigCacheTag.

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

Contains \Drupal\Core\Config\ConfigImporter.

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

Contains \Drupal\Core\EventSubscriber\ConfigImportSubscriber.

ConfigMapperManager.php in core/modules/config_translation/src/ConfigMapperManager.php

Contains \Drupal\config_translation\ConfigMapperManager.

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

Contains \Drupal\config\Form\ConfigSingleImportForm.

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

Contains \Drupal\config\Form\ConfigSync.

ConfigTranslationBlockListBuilder.php in core/modules/config_translation/src/Controller/ConfigTranslationBlockListBuilder.php

Contains \Drupal\config_translation\Controller\ConfigTranslationBlockListBuilder.

CurrentThemeCondition.php in core/modules/system/src/Plugin/Condition/CurrentThemeCondition.php

Contains \Drupal\system\Plugin\Condition\CurrentThemeCondition.

FilesystemLoader.php in core/lib/Drupal/Core/Template/Loader/FilesystemLoader.php

Contains \Drupal\Core\Template\Loader\FilesystemLoader.

NegotiationConfigureForm.php in core/modules/language/src/Form/NegotiationConfigureForm.php

Contains \Drupal\language\Form\NegotiationConfigureForm.

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

Contains \Drupal\Core\Theme\Registry.

SystemController.php in core/modules/system/src/Controller/SystemController.php

Contains \Drupal\system\Controller\SystemController.

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

Contains \Drupal\Core\Theme\ThemeAccessCheck.

ThemeController.php in core/modules/system/src/Controller/ThemeController.php

Contains \Drupal\system\Controller\ThemeController.

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

Contains \Drupal\Core\Theme\ThemeInitialization.

ThemeLocalTask.php in core/modules/block/src/Plugin/Derivative/ThemeLocalTask.php

Contains \Drupal\block\Plugin\Derivative\ThemeLocalTask.

ThemeLocalTask.php in core/modules/system/src/Plugin/Derivative/ThemeLocalTask.php

Contains \Drupal\system\Plugin\Derivative\ThemeLocalTask.

ThemeSettingsForm.php in core/modules/system/src/Form/ThemeSettingsForm.php

Contains \Drupal\system\Form\ThemeSettingsForm.

UpdateManager.php in core/modules/update/src/UpdateManager.php

Contains \Drupal\update\UpdateManager.