28 files declare their use of ThemeManagerInterface

AssetControllerBase.php in core/modules/system/src/Controller/AssetControllerBase.php
AssetResolver.php in core/lib/Drupal/Core/Asset/AssetResolver.php
BlockListBuilder.php in core/modules/block/src/BlockListBuilder.php
BlockRepository.php in core/modules/block/src/BlockRepository.php
ComponentNegotiator.php in core/modules/sdc/src/ComponentNegotiator.php
ComponentPluginManager.php in core/modules/sdc/src/ComponentPluginManager.php
CssCollectionOptimizerLazy.php in core/lib/Drupal/Core/Asset/CssCollectionOptimizerLazy.php
CssCollectionOptimizerLazyUnitTest.php in core/tests/Drupal/Tests/Core/Asset/CssCollectionOptimizerLazyUnitTest.php
CurrentThemeCondition.php in core/modules/system/src/Plugin/Condition/CurrentThemeCondition.php
ElementInfoManager.php in core/lib/Drupal/Core/Render/ElementInfoManager.php
FiberPlaceholderTest.php in core/modules/big_pipe/tests/src/Unit/Render/FiberPlaceholderTest.php
FilteredPluginManagerTrait.php in core/lib/Drupal/Core/Plugin/FilteredPluginManagerTrait.php
FilteredPluginManagerTraitTest.php in core/tests/Drupal/Tests/Core/Plugin/FilteredPluginManagerTraitTest.php
FormBuilder.php in core/lib/Drupal/Core/Form/FormBuilder.php
HtmlRenderer.php in core/lib/Drupal/Core/Render/MainContent/HtmlRenderer.php
JsCollectionOptimizerLazy.php in core/lib/Drupal/Core/Asset/JsCollectionOptimizerLazy.php
LayoutPluginManagerTest.php in core/tests/Drupal/Tests/Core/Layout/LayoutPluginManagerTest.php
LibraryDiscoveryCollector.php in core/lib/Drupal/Core/Asset/LibraryDiscoveryCollector.php
LibraryDiscoveryParser.php in core/lib/Drupal/Core/Asset/LibraryDiscoveryParser.php
LibraryDiscoveryParserTest.php in core/tests/Drupal/Tests/Core/Asset/LibraryDiscoveryParserTest.php
MenuTestController.php in core/modules/system/tests/modules/menu_test/src/Controller/MenuTestController.php
Renderer.php in core/lib/Drupal/Core/Render/Renderer.php
SettingsForm.php in core/modules/navigation/src/Form/SettingsForm.php
ThemeCacheContext.php in core/lib/Drupal/Core/Cache/Context/ThemeCacheContext.php
ThemeSettingsForm.php in core/modules/system/src/Form/ThemeSettingsForm.php
ToolbarClaroOverridesTest.php in core/modules/system/tests/src/Functional/Theme/ToolbarClaroOverridesTest.php
TwigExtension.php in core/lib/Drupal/Core/Template/TwigExtension.php
ViewEditForm.php in core/modules/views_ui/src/ViewEditForm.php

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