31 files declare their use of RedirectResponse in Zircon Profile 8

batch.inc in core/includes/batch.inc

Batch processing API for processes to run in multiple HTTP requests.

batch_test.callbacks.inc in core/modules/system/tests/modules/batch_test/batch_test.callbacks.inc

Batch callbacks for the Batch API tests.

CacheableRedirectResponse.php in core/lib/Drupal/Core/Cache/CacheableRedirectResponse.php

Contains \Drupal\Core\Cache\CacheableRedirectResponse.

CacheableSecuredRedirectResponse.php in core/lib/Drupal/Core/Routing/CacheableSecuredRedirectResponse.php

Contains \Drupal\Core\Routing\CacheableSecuredRedirectResponse.

CommentController.php in core/modules/comment/src/Controller/CommentController.php

Contains \Drupal\comment\Controller\CommentController.

ConfigTestController.php in core/modules/config/tests/config_test/src/ConfigTestController.php

Contains \Drupal\config_test\ConfigTestController.

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

Contains \Drupal\system\Form\CronForm.

DeleteMultiple.php in core/modules/node/src/Form/DeleteMultiple.php

Contains \Drupal\node\Form\DeleteMultiple.

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

Contains \Drupal\Core\DrupalKernel.

form.inc in core/includes/form.inc

Functions for form and batch generation and processing.

FormStateTest.php in core/tests/Drupal/Tests/Core/Form/FormStateTest.php

Contains \Drupal\Tests\Core\Form\FormStateTest.

FormSubmitter.php in core/lib/Drupal/Core/Form/FormSubmitter.php

Contains \Drupal\Core\Form\FormSubmitter.

FormSubmitterTest.php in core/tests/Drupal/Tests/Core/Form/FormSubmitterTest.php

Contains \Drupal\Tests\Core\Form\FormSubmitterTest.

GotoAction.php in core/modules/action/src/Plugin/Action/GotoAction.php

Contains \Drupal\action\Plugin\Action\GotoAction.

HttpKernelTest.php in vendor/symfony/http-kernel/Tests/HttpKernelTest.php

install.inc in core/includes/install.inc

API functions for installing modules and themes.

locale.pages.inc in core/modules/locale/locale.pages.inc

Interface translation summary, editing and deletion user interfaces.

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

Contains \Drupal\Core\EventSubscriber\RedirectResponseSubscriber.

RedirectResponseSubscriberTest.php in core/tests/Drupal/Tests/Core/EventSubscriber/RedirectResponseSubscriberTest.php

Contains \Drupal\Tests\Core\EventSubscriber\RedirectResponseSubscriberTest.

RedirectResponseTest.php in vendor/symfony/http-foundation/Tests/RedirectResponseTest.php

RouterDataCollector.php in vendor/symfony/http-kernel/DataCollector/RouterDataCollector.php

SecuredRedirectResponse.php in core/lib/Drupal/Component/HttpFoundation/SecuredRedirectResponse.php

Contains \Drupal\Component\HttpFoundation\SecuredRedirectResponse.

SecuredRedirectResponseTest.php in core/tests/Drupal/Tests/Component/HttpFoundation/SecuredRedirectResponseTest.php

Contains \Drupal\Tests\Component\HttpFoundation\SecuredRedirectResponseTest.

SimpletestResultsForm.php in core/modules/simpletest/src/Form/SimpletestResultsForm.php

Contains \Drupal\simpletest\Form\SimpletestResultsForm.

system.module in core/modules/system/system.module

Configuration system that lets administrators modify the workings of the site.

SystemTestController.php in core/modules/system/tests/modules/system_test/src/Controller/SystemTestController.php

Contains \Drupal\system_test\Controller\SystemTestController.

ToolbarController.php in modules/admin_toolbar/admin_toolbar_tools/src/Controller/ToolbarController.php

Contains \Drupal\admin_toolbar_tools\Controller\ToolbarController.

TrustedRedirectResponseTest.php in core/tests/Drupal/Tests/Core/Routing/TrustedRedirectResponseTest.php

Contains \Drupal\Tests\Core\Routing\TrustedRedirectResponseTest.

update.manager.inc in core/modules/update/update.manager.inc

Administrative screens and processing functions of the Update Manager module.

UrlGeneratorTrait.php in core/lib/Drupal/Core/Routing/UrlGeneratorTrait.php

Contains \Drupal\Core\Routing\UrlGeneratorTrait.

ViewsFormBase.php in core/modules/views_ui/src/Form/Ajax/ViewsFormBase.php

Contains \Drupal\views_ui\Form\Ajax\ViewsFormBase.