core/modules/rest/rest.install                     | 36 -------------
 core/modules/rest/rest.module                      | 27 ----------
 .../rest/src/Plugin/views/display/RestExport.php   | 18 -------
 .../Update/RestExportAuthCorrectionUpdateTest.php  | 36 -------------
 .../rest-export-with-authentication-correction.php | 63 ----------------------
 5 files changed, 180 deletions(-)

diff --git a/core/modules/rest/rest.install b/core/modules/rest/rest.install
index a20956f..c2d9412 100644
--- a/core/modules/rest/rest.install
+++ b/core/modules/rest/rest.install
@@ -24,39 +24,3 @@ function rest_requirements($phase) {
   }
   return $requirements;
 }
-
-/**
- * Ensure the right REST authentication method is used.
- *
- * This fixes the bug in https://www.drupal.org/node/2825204.
- */
-function rest_update_8401() {
-  $config_factory = \Drupal::configFactory();
-  $auth_providers = \Drupal::service('authentication_collector')->getSortedProviders();
-  $process_auth = function ($auth_option) use ($auth_providers) {
-    foreach ($auth_providers as $provider_id => $provider_data) {
-      // The provider belongs to the module that declares it as a service.
-      if (strtok($provider_data->_serviceId, '.') === $auth_option) {
-        return $provider_id;
-      }
-    }
-
-    return $auth_option;
-  };
-
-  foreach ($config_factory->listAll('views.view.') as $view_config_name) {
-    $save = FALSE;
-    $view = $config_factory->getEditable($view_config_name);
-    $displays = $view->get('display');
-    foreach ($displays as $display_name => $display) {
-      if ('rest_export' === $display['display_plugin'] && !empty($display['display_options']['auth'])) {
-        $displays[$display_name]['display_options']['auth'] = array_map($process_auth, $display['display_options']['auth']);
-        $save = TRUE;
-      }
-    }
-    if ($save) {
-      $view->set('display', $displays);
-      $view->save(TRUE);
-    }
-  }
-}
diff --git a/core/modules/rest/rest.module b/core/modules/rest/rest.module
index ba61a17..3c061af 100644
--- a/core/modules/rest/rest.module
+++ b/core/modules/rest/rest.module
@@ -28,30 +28,3 @@ function rest_help($route_name, RouteMatchInterface $route_match) {
       return $output;
   }
 }
-
-/**
- * Implements hook_view_presave().
- *
- * @see rest_update_8401()
- */
-function rest_view_presave(ViewEntityInterface $view) {
-  // Fix the auth options on import, much like what rest_update_8401() does.
-  $auth_providers = \Drupal::service('authentication_collector')->getSortedProviders();
-  $process_auth = function ($auth_option) use ($auth_providers) {
-    foreach ($auth_providers as $provider_id => $provider_data) {
-      // The provider belongs to the module that declares it as a service.
-      if (strtok($provider_data->_serviceId, '.') === $auth_option) {
-        return $provider_id;
-      }
-    }
-
-    return $auth_option;
-  };
-
-  foreach (array_keys($view->get('display')) as $display_id) {
-    $display = &$view->getDisplay($display_id);
-    if ($display['display_plugin'] === 'rest_export' && !empty($display['display_options']['auth'])) {
-      $display['display_options']['auth'] = array_map($process_auth, $display['display_options']['auth']);
-    }
-  }
-}
diff --git a/core/modules/rest/src/Plugin/views/display/RestExport.php b/core/modules/rest/src/Plugin/views/display/RestExport.php
index 52daee0..2b33cff 100644
--- a/core/modules/rest/src/Plugin/views/display/RestExport.php
+++ b/core/modules/rest/src/Plugin/views/display/RestExport.php
@@ -94,22 +94,6 @@ class RestExport extends PathPluginBase implements ResponseDisplayPluginInterfac
   protected $authenticationProviderIds;
 
   /**
-   * The authentication providers' modules, keyed by provider ID.
-   *
-   * Authentication providers like 'cookie' and 'basic_auth' are the array
-   * keys. The array values are the module names, e.g.:
-   * @code
-   *   ['cookie' => 'user', 'basic_auth' => 'basic_auth']
-   * @endcode
-   *
-   * @deprecated as of 8.4.x, will be removed in before Drupal 9.0.0, see
-   *   https://www.drupal.org/node/2825204.
-   *
-   * @var string[]
-   */
-  protected $authenticationProviders;
-
-  /**
    * The serialization format providers, keyed by format.
    *
    * @var string[]
@@ -146,8 +130,6 @@ public function __construct(array $configuration, $plugin_id, $plugin_definition
     // basic_auth) as keys and modules providing those as values (user,
     // basic_auth).
     $this->authenticationProviderIds = array_keys($authentication_providers);
-    // For BC reasons we keep around authenticationProviders as before.
-    $this->authenticationProviders = $authentication_providers;
     $this->formatProviders = $serializer_format_providers;
   }
 
diff --git a/core/modules/rest/src/Tests/Update/RestExportAuthCorrectionUpdateTest.php b/core/modules/rest/src/Tests/Update/RestExportAuthCorrectionUpdateTest.php
deleted file mode 100644
index aeca71f..0000000
--- a/core/modules/rest/src/Tests/Update/RestExportAuthCorrectionUpdateTest.php
+++ /dev/null
@@ -1,36 +0,0 @@
-<?php
-
-namespace Drupal\rest\Tests\Update;
-
-use Drupal\system\Tests\Update\UpdatePathTestBase;
-
-/**
- * Ensures that update hook is run properly for REST Export config.
- *
- * @group Update
- */
-class RestExportAuthCorrectionUpdateTest extends UpdatePathTestBase {
-
-  /**
-   * {@inheritdoc}
-   */
-  protected function setDatabaseDumpFiles() {
-    $this->databaseDumpFiles = [
-      __DIR__ . '/../../../../system/tests/fixtures/update/drupal-8.bare.standard.php.gz',
-      __DIR__ . '/../../../tests/fixtures/update/rest-export-with-authentication-correction.php',
-    ];
-  }
-
-  /**
-   * Ensures that update hook is run for "rest" module.
-   */
-  public function testUpdate() {
-    $this->runUpdates();
-
-    // Get particular view.
-    $view = \Drupal::entityTypeManager()->getStorage('view')->load('rest_export_with_authorization_correction');
-    $displays = $view->get('display');
-    $this->assertIdentical($displays['rest_export_1']['display_options']['auth'], ['cookie'], 'Cookie is used for authentication');
-  }
-
-}
diff --git a/core/modules/rest/tests/fixtures/update/rest-export-with-authentication-correction.php b/core/modules/rest/tests/fixtures/update/rest-export-with-authentication-correction.php
deleted file mode 100644
index 6cbd04e..0000000
--- a/core/modules/rest/tests/fixtures/update/rest-export-with-authentication-correction.php
+++ /dev/null
@@ -1,63 +0,0 @@
-<?php
-
-/**
- * @file
- * Test fixture for \Drupal\rest\Tests\Update\RestExportAuthCorrectionUpdateTest.
- */
-
-use Drupal\Core\Database\Database;
-use Drupal\Core\Serialization\Yaml;
-
-$connection = Database::getConnection();
-
-// Set the schema version.
-$connection->insert('key_value')
-  ->fields([
-    'collection' => 'system.schema',
-    'name' => 'rest',
-    'value' => 'i:8000;',
-  ])
-  ->execute();
-
-// Update core.extension.
-$extensions = $connection->select('config')
-  ->fields('config', ['data'])
-  ->condition('collection', '')
-  ->condition('name', 'core.extension')
-  ->execute()
-  ->fetchField();
-$extensions = unserialize($extensions);
-$extensions['module']['rest'] = 0;
-$extensions['module']['serialization'] = 0;
-$extensions['module']['basic_auth'] = 0;
-$connection->update('config')
-  ->fields([
-    'data' => serialize($extensions),
-  ])
-  ->condition('collection', '')
-  ->condition('name', 'core.extension')
-  ->execute();
-
-$connection->insert('config')
-  ->fields([
-    'name' => 'rest.settings',
-    'data' => serialize([
-      'link_domain' => '~',
-    ]),
-    'collection' => '',
-  ])
-  ->execute();
-
-$connection->insert('config')
-  ->fields([
-    'name' => 'views.view.rest_export_with_authorization_correction',
-  ])
-  ->execute();
-
-$connection->merge('config')
-  ->condition('name', 'views.view.rest_export_with_authorization_correction')
-  ->condition('collection', '')
-  ->fields([
-    'data' => serialize(Yaml::decode(file_get_contents('core/modules/views/tests/modules/views_test_config/test_views/views.view.rest_export_with_authorization_correction.yml'))),
-  ])
-  ->execute();