diff --git a/core/modules/system/lib/Drupal/system/Tests/Lock/LockFunctionalTest.php b/core/modules/system/lib/Drupal/system/Tests/Lock/LockFunctionalTest.php
index bf868db..fefb9d1e 100644
--- a/core/modules/system/lib/Drupal/system/Tests/Lock/LockFunctionalTest.php
+++ b/core/modules/system/lib/Drupal/system/Tests/Lock/LockFunctionalTest.php
@@ -33,8 +33,8 @@ public static function getInfo() {
    * Confirms that we can acquire and release locks in two parallel requests.
    */
   public function testLockAcquire() {
-    $lock_acquired = 'TRUE: Lock successfully acquired in system_test_lock_acquire()';
-    $lock_not_acquired = 'FALSE: Lock not acquired in system_test_lock_acquire()';
+    $lock_acquired = 'TRUE: Lock successfully acquired in \Drupal\system_test\Controller\SystemTestController::lockAcquire()';
+    $lock_not_acquired = 'FALSE: Lock not acquired in \Drupal\system_test\Controller\SystemTestController::lockAcquire()';
     $this->assertTrue(lock()->acquire('system_test_lock_acquire'), 'Lock acquired by this request.', 'Lock');
     $this->assertTrue(lock()->acquire('system_test_lock_acquire'), 'Lock extended by this request.', 'Lock');
     lock()->release('system_test_lock_acquire');
@@ -59,8 +59,8 @@ public function testLockAcquire() {
     $this->assertFalse(lock()->acquire('system_test_lock_acquire'), 'Lock cannot be extended by this request.', 'Lock');
 
     // Check the shut-down function.
-    $lock_acquired_exit = 'TRUE: Lock successfully acquired in system_test_lock_exit()';
-    $lock_not_acquired_exit = 'FALSE: Lock not acquired in system_test_lock_exit()';
+    $lock_acquired_exit = 'TRUE: Lock successfully acquired in \Drupal\system_test\Controller\SystemTestController::lockExit()';
+    $lock_not_acquired_exit = 'FALSE: Lock not acquired in \Drupal\system_test\Controller\SystemTestController::lockExit()';
     $this->drupalGet('system-test/lock-exit');
     $this->assertText($lock_acquired_exit, 'Lock acquired by the other request before exit.', 'Lock');
     $this->assertTrue(lock()->acquire('system_test_lock_exit'), 'Lock acquired by this request after the other request exits.', 'Lock');
diff --git a/core/modules/system/tests/modules/system_test/lib/Drupal/system_test/Controller/SystemTestController.php b/core/modules/system/tests/modules/system_test/lib/Drupal/system_test/Controller/SystemTestController.php
index 058aabe..e613c5f 100644
--- a/core/modules/system/tests/modules/system_test/lib/Drupal/system_test/Controller/SystemTestController.php
+++ b/core/modules/system/tests/modules/system_test/lib/Drupal/system_test/Controller/SystemTestController.php
@@ -8,6 +8,7 @@
 namespace Drupal\system_test\Controller;
 
 use Drupal\Core\Controller\ControllerBase;
+use Symfony\Component\HttpFoundation\Response;
 
 /**
  * Controller routines for system_test routes.
@@ -25,17 +26,31 @@ public function mainContentFallback() {
   }
 
   /**
-   * @todo Remove system_test_lock_acquire().
+   * Try to acquire a named lock and report the outcome.
    */
   public function lockAcquire() {
-    return system_test_lock_acquire();
+    if (\Drupal::lock()->acquire('system_test_lock_exit', 900)) {
+      echo 'TRUE: Lock successfully acquired in \Drupal\system_test\Controller\SystemTestController::lockExit()';
+      // The shut-down function should release the lock.
+      exit();
+    }
+    else {
+      return 'FALSE: Lock not acquired in \Drupal\system_test\Controller\SystemTestController::lockExit()';
+    }
   }
 
   /**
-   * @todo Remove system_test_lock_exit().
+   * Try to acquire a specific lock, and then exit.
    */
   public function lockExit() {
-    return system_test_lock_exit();
+    if (\Drupal::lock()->acquire('system_test_lock_exit', 900)) {
+      echo 'TRUE: Lock successfully acquired in \Drupal\system_test\Controller\SystemTestController::lockExit()';
+      // The shut-down function should release the lock.
+      exit();
+    }
+    else {
+      return 'FALSE: Lock not acquired in \Drupal\system_test\Controller\SystemTestController::lockExit()';
+    }
   }
 
   /**
@@ -50,10 +65,14 @@ function system_test_cache_tags_page() {
   }
 
   /**
-   * @todo Remove system_test_authorize_init_page().
+   * Initialize authorize.php during testing.
+   *
+   * @see system_authorized_init().
    */
   public function authorizeInit($page_title) {
-    return system_test_authorize_init_page($page_title);
+    $authorize_url = $GLOBALS['base_url'] . '/core/authorize.php';
+    system_authorized_init('system_test_authorize_run', drupal_get_path('module', 'system_test') . '/system_test.module', array(), $page_title);
+    return new RedirectResponse($authorize_url);
   }
 
   /**
@@ -64,17 +83,18 @@ public function variableGet() {
   }
 
   /**
-   * @todo Remove system_test_set_header().
+   * Sets a header.
    */
-  public function setHeader() {
-    return system_test_set_header();
+  public function setHeader(Response $response = NULL) {
+    $response->headers->set($_GET['name'], $_GET['value']);
+    return t('The following header was set: %name: %value', array('%name' => $_GET['name'], '%value' => $_GET['value']));
   }
 
   /**
-   * @todo Remove system_test_page_shutdown_functions().
+   * A simple page callback which adds a register shutdown function.
    */
   public function shutdownFunctions($arg1, $arg2) {
-    system_test_page_shutdown_functions($arg1, $arg2);
+    drupal_register_shutdown_function('_system_test_first_shutdown_function', $arg1, $arg2);
   }
 
 }
diff --git a/core/modules/system/tests/modules/system_test/system_test.module b/core/modules/system/tests/modules/system_test/system_test.module
index 56ae206..fd44872 100644
--- a/core/modules/system/tests/modules/system_test/system_test.module
+++ b/core/modules/system/tests/modules/system_test/system_test.module
@@ -71,37 +71,6 @@ function system_test_system_info_alter(&$info, $file, $type) {
 }
 
 /**
- * Try to acquire a named lock and report the outcome.
- *
- * @deprecated \Drupal\system_test\Controller\SystemTestController::lockAcquire()
- */
-function system_test_lock_acquire() {
-  if (lock()->acquire('system_test_lock_acquire')) {
-    lock()->release('system_test_lock_acquire');
-    return 'TRUE: Lock successfully acquired in system_test_lock_acquire()';
-  }
-  else {
-    return 'FALSE: Lock not acquired in system_test_lock_acquire()';
-  }
-}
-
-/**
- * Try to acquire a specific lock, and then exit.
- *
- * @deprecated \Drupal\system_test\Controller\SystemTestController::lockExit()
- */
-function system_test_lock_exit() {
-  if (lock()->acquire('system_test_lock_exit', 900)) {
-    echo 'TRUE: Lock successfully acquired in system_test_lock_exit()';
-    // The shut-down function should release the lock.
-    exit();
-  }
-  else {
-    return 'FALSE: Lock not acquired in system_test_lock_exit()';
-  }
-}
-
-/**
  * Implements hook_page_build().
  */
 function system_test_page_build(&$page) {
@@ -174,19 +143,6 @@ function system_test_filetransfer_info() {
 }
 
 /**
- * Page callback to initialize authorize.php during testing.
- *
- * @see system_authorized_init().
- *
- * @deprecated \Drupal\system_test\Controller\SystemTestController::authorizeInit()
- */
-function system_test_authorize_init_page($page_title) {
-  $authorize_url = $GLOBALS['base_url'] . '/core/authorize.php';
-  system_authorized_init('system_test_authorize_run', drupal_get_path('module', 'system_test') . '/system_test.module', array(), $page_title);
-  return new RedirectResponse($authorize_url);
-}
-
-/**
  * Implements hook_module_preinstall().
  */
 function system_test_module_preinstall($module) {