20 files declare their use of FileCacheFactory in Drupal 8

AnnotatedClassDiscovery.php in core/lib/Drupal/Component/Annotation/Plugin/Discovery/AnnotatedClassDiscovery.php

AnnotatedClassDiscoveryCachedTest.php in core/tests/Drupal/Tests/Component/Annotation/AnnotatedClassDiscoveryCachedTest.php

AnnotatedClassDiscoveryTest.php in core/tests/Drupal/Tests/Component/Annotation/AnnotatedClassDiscoveryTest.php

AnnotatedClassDiscoveryTest.php in core/tests/Drupal/Tests/Component/Plugin/Discovery/AnnotatedClassDiscoveryTest.php

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

ExtensionDiscovery.php in core/lib/Drupal/Core/Extension/ExtensionDiscovery.php

FileCacheFactoryTest.php in core/tests/Drupal/Tests/Component/FileCache/FileCacheFactoryTest.php

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

FunctionalTestSetupTrait.php in core/lib/Drupal/Core/Test/FunctionalTestSetupTrait.php

HelpTopicDiscovery.php in core/modules/help_topics/src/HelpTopicDiscovery.php

KernelTestBase.php in core/tests/Drupal/KernelTests/KernelTestBase.php

KernelTestBaseTest.php in core/tests/Drupal/KernelTests/KernelTestBaseTest.php

UnitTestCase.php in core/tests/Drupal/Tests/UnitTestCase.php

YamlDirectoryDiscovery.php in core/lib/Drupal/Component/Discovery/YamlDirectoryDiscovery.php

YamlDirectoryDiscoveryTest.php in core/tests/Drupal/Tests/Component/Discovery/YamlDirectoryDiscoveryTest.php

YamlDiscovery.php in core/lib/Drupal/Component/Discovery/YamlDiscovery.php

YamlDiscoveryTest.php in core/tests/Drupal/Tests/Core/Discovery/YamlDiscoveryTest.php

YamlDiscoveryTest.php in core/tests/Drupal/Tests/Component/Discovery/YamlDiscoveryTest.php

YamlFileLoader.php in core/lib/Drupal/Core/DependencyInjection/YamlFileLoader.php

YamlFileLoaderTest.php in core/tests/Drupal/Tests/Core/DependencyInjection/YamlFileLoaderTest.php