14 files declare their use of RequestPolicyInterface

AllowToolbarPath.php in core/modules/toolbar/src/PageCache/AllowToolbarPath.php
AllowToolbarPathTest.php in core/modules/toolbar/tests/src/Unit/PageCache/AllowToolbarPathTest.php
ChainRequestPolicyTest.php in core/tests/Drupal/Tests/Core/PageCache/ChainRequestPolicyTest.php
CommandLineOrUnsafeMethod.php in core/lib/Drupal/Core/PageCache/RequestPolicy/CommandLineOrUnsafeMethod.php
CommandLineOrUnsafeMethodTest.php in core/tests/Drupal/Tests/Core/PageCache/CommandLineOrUnsafeMethodTest.php
DenyTestAuthRequests.php in core/modules/rest/tests/modules/rest_test/src/PageCache/RequestPolicy/DenyTestAuthRequests.php
DisallowBasicAuthRequests.php in core/modules/basic_auth/src/PageCache/DisallowBasicAuthRequests.php
DynamicPageCacheSubscriber.php in core/modules/dynamic_page_cache/src/EventSubscriber/DynamicPageCacheSubscriber.php
FinishResponseSubscriber.php in core/lib/Drupal/Core/EventSubscriber/FinishResponseSubscriber.php
FormCache.php in core/lib/Drupal/Core/Form/FormCache.php
NoSessionOpen.php in core/lib/Drupal/Core/PageCache/RequestPolicy/NoSessionOpen.php
NoSessionOpenTest.php in core/tests/Drupal/Tests/Core/PageCache/NoSessionOpenTest.php
PageCache.php in core/modules/page_cache/src/StackMiddleware/PageCache.php
system.module in core/modules/system/system.module
Configuration system that lets administrators modify the workings of the site.

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