diff --git a/core/includes/menu.inc b/core/includes/menu.inc
index b2e115d..826ca09 100644
--- a/core/includes/menu.inc
+++ b/core/includes/menu.inc
@@ -93,7 +93,7 @@ function menu_list_system_menus() {
 }
 
 /**
- * Collects the local tasks (tabs), action links, and the root path.
+ * Collects the local tasks (tabs) for the current route.
  *
  * @param int $level
  *   The level of tasks you ask for. Primary tasks are 0, secondary are 1.
@@ -101,64 +101,26 @@ function menu_list_system_menus() {
  * @return array
  *   An array containing
  *   - tabs: Local tasks for the requested level.
- *   - actions: Action links for the requested level.
- *   - root_path: The router path for the current page. If the current page is
- *     a default local task, then this corresponds to the parent tab.
+ *   - route_name: The route name for the current page used to collect the local
+ *     tasks.
  *
- * @see hook_menu_local_tasks()
  * @see hook_menu_local_tasks_alter()
+ *
+ * @deprecated in Drupal 8.0.0, will be removed before Drupal 9.0.0.
  */
 function menu_local_tasks($level = 0) {
-  $data = &drupal_static(__FUNCTION__);
-  $root_path = &drupal_static(__FUNCTION__ . ':root_path', '');
-  $empty = array(
-    'tabs' => array(),
-    'actions' => array(),
-    'root_path' => &$root_path,
-  );
-
-  if (!isset($data)) {
-    // Look for route-based tabs.
-    $data['tabs'] = array();
-    $data['actions'] = array();
-
-    $route_name = \Drupal::routeMatch()->getRouteName();
-    if (!\Drupal::request()->attributes->has('exception') && !empty($route_name)) {
-      $manager = \Drupal::service('plugin.manager.menu.local_task');
-      $local_tasks = $manager->getTasksBuild($route_name);
-      foreach ($local_tasks as $tab_level => $items) {
-        $data['tabs'][$tab_level] = empty($data['tabs'][$tab_level]) ? $items : array_merge($data['tabs'][$tab_level], $items);
-      }
-    }
-
-    // Allow modules to dynamically add further tasks.
-    $module_handler = \Drupal::moduleHandler();
-    foreach ($module_handler->getImplementations('menu_local_tasks') as $module) {
-      $function = $module . '_menu_local_tasks';
-      $function($data, $route_name);
-    }
-    // Allow modules to alter local tasks.
-    $module_handler->alter('menu_local_tasks', $data, $route_name);
-  }
-
-  if (isset($data['tabs'][$level])) {
-    return array(
-      'tabs' => $data['tabs'][$level],
-      'actions' => $data['actions'],
-      'root_path' => $root_path,
-    );
-  }
-  elseif (!empty($data['actions'])) {
-    return array('actions' => $data['actions']) + $empty;
-  }
-  return $empty;
+  /** @var \Drupal\Core\Menu\LocalTaskManagerInterface $manager */
+  $manager = \Drupal::service('plugin.manager.menu.local_task');
+  return $manager->getLocalTasks($level);
 }
 
 /**
  * Returns the rendered local tasks at the top level.
  */
 function menu_primary_local_tasks() {
-  $links = menu_local_tasks(0);
+  /** @var \Drupal\Core\Menu\LocalTaskManagerInterface $manager */
+  $manager = \Drupal::service('plugin.manager.menu.local_task');
+  $links = $manager->getLocalTasks(0);
   // Do not display single tabs.
   return count(Element::getVisibleChildren($links['tabs'])) > 1 ? $links['tabs'] : '';
 }
@@ -167,20 +129,14 @@ function menu_primary_local_tasks() {
  * Returns the rendered local tasks at the second level.
  */
 function menu_secondary_local_tasks() {
-  $links = menu_local_tasks(1);
+  /** @var \Drupal\Core\Menu\LocalTaskManagerInterface $manager */
+  $manager = \Drupal::service('plugin.manager.menu.local_task');
+  $links = $manager->getLocalTasks(1);
   // Do not display single tabs.
   return count(Element::getVisibleChildren($links['tabs'])) > 1 ? $links['tabs'] : '';
 }
 
 /**
- * Returns the router path, or the path for a default local task's parent.
- */
-function menu_tab_root_path() {
-  $links = menu_local_tasks();
-  return $links['root_path'];
-}
-
-/**
  * Returns a renderable element for the primary and secondary tabs.
  */
 function menu_local_tabs() {
diff --git a/core/lib/Drupal/Core/Menu/LocalTaskManager.php b/core/lib/Drupal/Core/Menu/LocalTaskManager.php
index 3f2ab8b..bc422fd 100644
--- a/core/lib/Drupal/Core/Menu/LocalTaskManager.php
+++ b/core/lib/Drupal/Core/Menu/LocalTaskManager.php
@@ -82,6 +82,13 @@ class LocalTaskManager extends DefaultPluginManager implements LocalTaskManagerI
   protected $instances = array();
 
   /**
+   * The local task render arrays for the current route.
+   *
+   * @var array
+   */
+  protected $taskData;
+
+  /**
    * The route provider to load routes by name.
    *
    * @var \Drupal\Core\Routing\RouteProviderInterface
@@ -296,6 +303,8 @@ public function getTasksBuild($current_route_name) {
     // of SQL queries that would otherwise be triggered by the access manager.
     $routes = $route_names ? $this->routeProvider->getRoutesByNames($route_names) : array();
 
+    // @todo add cacheability data in https://www.drupal.org/node/2511516 so
+    // that we are not re-building inaccessible links on every page request.
     foreach ($tree as $level => $instances) {
       /** @var $instances \Drupal\Core\Menu\LocalTaskInterface[] */
       foreach ($instances as $plugin_id => $child) {
@@ -328,6 +337,43 @@ public function getTasksBuild($current_route_name) {
   }
 
   /**
+   * {@inheritdoc}
+   */
+  public function getLocalTasks($level = 0) {
+
+    if (!isset($this->taskData)) {
+      $route_name = $this->routeMatch->getRouteName();
+      // Look for route-based tabs.
+      $this->taskData = array(
+        'tabs' => array(),
+        'route_name' => $route_name,
+      );
+
+      if (!empty($route_name) && !$this->requestStack->getCurrentRequest()->attributes->has('exception')) {
+        $data = array();
+        $local_tasks = $this->getTasksBuild($route_name);
+        foreach ($local_tasks as $tab_level => $items) {
+          $data[$tab_level] = empty($data[$tab_level]) ? $items : array_merge($data[$tab_level], $items);
+        }
+        $this->taskData['tabs'] = $data;
+      }
+      // Allow modules to alter local tasks.
+      $this->moduleHandler->alter('menu_local_tasks', $this->taskData, $route_name);
+    }
+
+    if (isset($this->taskData['tabs'][$level])) {
+      return array(
+        'tabs' => $this->taskData['tabs'][$level],
+        'route_name' => $this->taskData['route_name'],
+      );
+    }
+    return array(
+      'tabs' => array(),
+      'route_name' => $this->taskData['route_name'],
+    );
+  }
+
+  /**
    * Determines whether the route of a certain local task is currently active.
    *
    * @param string $current_route_name
diff --git a/core/lib/Drupal/Core/Menu/LocalTaskManagerInterface.php b/core/lib/Drupal/Core/Menu/LocalTaskManagerInterface.php
index e75307d..e7ec7b1 100644
--- a/core/lib/Drupal/Core/Menu/LocalTaskManagerInterface.php
+++ b/core/lib/Drupal/Core/Menu/LocalTaskManagerInterface.php
@@ -53,4 +53,20 @@ public function getLocalTasksForRoute($route_name);
    */
   public function getTasksBuild($current_route_name);
 
+  /**
+   * Collects the local tasks (tabs) for the current route.
+   *
+   * @param int $level
+   *   The level of tasks you ask for. Primary tasks are 0, secondary are 1.
+   *
+   * @return array
+   *   An array containing
+   *   - tabs: Local tasks render array for the requested level.
+   *   - route_name: The route name for the current page used to collect the
+   *     local tasks.
+   *
+   * @see hook_menu_local_tasks_alter()
+   */
+  public function getLocalTasks($level = 0);
+
 }
diff --git a/core/lib/Drupal/Core/Menu/menu.api.php b/core/lib/Drupal/Core/Menu/menu.api.php
index 8550fc5..87c2c71 100644
--- a/core/lib/Drupal/Core/Menu/menu.api.php
+++ b/core/lib/Drupal/Core/Menu/menu.api.php
@@ -377,48 +377,35 @@ function hook_menu_links_discovered_alter(&$links) {
 }
 
 /**
- * Alter tabs and actions displayed on the page before they are rendered.
+ * Alter local tasks displayed on the page before they are rendered.
  *
  * This hook is invoked by menu_local_tasks(). The system-determined tabs and
- * actions are passed in by reference. Additional tabs or actions may be added.
+ * actions are passed in by reference. Additional tabs may be added.
  *
- * Each tab or action is an associative array containing:
+ * The local tasks are under the 'tabs' element and keyed by plugin ID.
+ *
+ * Each local task is an associative array containing:
  * - #theme: The theme function to use to render.
  * - #link: An associative array containing:
  *   - title: The localized title of the link.
- *   - href: The system path to link to.
+ *   - url: a Url object.
  *   - localized_options: An array of options to pass to _l().
  * - #weight: The link's weight compared to other links.
  * - #active: Whether the link should be marked as 'active'.
  *
  * @param array $data
- *   An associative array containing:
- *   - actions: A list of of actions keyed by their href, each one being an
- *     associative array as described above.
- *   - tabs: A list of (up to 2) tab levels that contain a list of of tabs keyed
- *     by their href, each one being an associative array as described above.
+ *   An associative array containing list of (up to 2) tab levels that contain a
+ *   list of of tabs keyed by their href, each one being an associative array
+ *   as described above.
  * @param string $route_name
  *   The route name of the page.
  *
  * @ingroup menu
  */
-function hook_menu_local_tasks(&$data, $route_name) {
-  // Add an action linking to node/add to all pages.
-  $data['actions']['node/add'] = array(
-      '#theme' => 'menu_local_action',
-      '#link' => array(
-          'title' => t('Add content'),
-          'url' => Url::fromRoute('node.add_page'),
-          'localized_options' => array(
-              'attributes' => array(
-                  'title' => t('Add content'),
-              ),
-          ),
-      ),
-  );
+function hook_menu_local_tasks_alter(&$data, $route_name) {
 
   // Add a tab linking to node/add to all pages.
-  $data['tabs'][0]['node/add'] = array(
+  $data['tabs'][0]['node.add_page'] = array(
       '#theme' => 'menu_local_task',
       '#link' => array(
           'title' => t('Example tab'),
@@ -433,25 +420,6 @@ function hook_menu_local_tasks(&$data, $route_name) {
 }
 
 /**
- * Alter tabs and actions displayed on the page before they are rendered.
- *
- * This hook is invoked by menu_local_tasks(). The system-determined tabs and
- * actions are passed in by reference. Existing tabs or actions may be altered.
- *
- * @param array $data
- *   An associative array containing tabs and actions. See
- *   hook_menu_local_tasks() for details.
- * @param string $route_name
- *   The route name of the page.
- *
- * @see hook_menu_local_tasks()
- *
- * @ingroup menu
- */
-function hook_menu_local_tasks_alter(&$data, $route_name) {
-}
-
-/**
  * Alter local actions plugins.
  *
  * @param array $local_actions
diff --git a/core/modules/system/src/Plugin/Block/SystemLocalActionsBlock.php b/core/modules/system/src/Plugin/Block/SystemLocalActionsBlock.php
index 23a65c0..30e690b 100644
--- a/core/modules/system/src/Plugin/Block/SystemLocalActionsBlock.php
+++ b/core/modules/system/src/Plugin/Block/SystemLocalActionsBlock.php
@@ -83,9 +83,8 @@ public function defaultConfiguration() {
    */
   public function build() {
     $build = [];
-    $links = menu_local_tasks();
     $route_name = $this->routeMatch->getRouteName();
-    $local_actions = $this->localActionManager->getActionsForRoute($route_name) + $links['actions'];
+    $local_actions = $this->localActionManager->getActionsForRoute($route_name);
     if (empty($local_actions)) {
       return [];
     }
diff --git a/core/modules/system/src/Plugin/Block/SystemLocalTasksBlock.php b/core/modules/system/src/Plugin/Block/SystemLocalTasksBlock.php
index bbbbb9d..897900a 100644
--- a/core/modules/system/src/Plugin/Block/SystemLocalTasksBlock.php
+++ b/core/modules/system/src/Plugin/Block/SystemLocalTasksBlock.php
@@ -9,7 +9,9 @@
 
 use Drupal\Core\Block\BlockBase;
 use Drupal\Core\Form\FormStateInterface;
+use Drupal\Core\Menu\LocalTaskManagerInterface;
 use Drupal\Core\Plugin\ContainerFactoryPluginInterface;
+use Drupal\Core\Render\Element;
 use Symfony\Component\DependencyInjection\ContainerInterface;
 
 /**
@@ -23,13 +25,38 @@
 class SystemLocalTasksBlock extends BlockBase implements ContainerFactoryPluginInterface {
 
   /**
+   * The local task manager.
+   *
+   * @var \Drupal\Core\Menu\LocalTaskManagerInterface
+   */
+  protected $localTaskManager;
+
+  /**
+   * Creates a SystemLocalTasksBlock instance.
+   *
+   * @param array $configuration
+   *   A configuration array containing information about the plugin instance.
+   * @param string $plugin_id
+   *   The plugin_id for the plugin instance.
+   * @param mixed $plugin_definition
+   *   The plugin implementation definition.
+   * @param \Drupal\Core\Menu\LocalTaskManagerInterface $local_task_manager
+   *   The local task manager.
+   */
+  public function __construct(array $configuration, $plugin_id, $plugin_definition, LocalTaskManagerInterface $local_task_manager) {
+    parent::__construct($configuration, $plugin_id, $plugin_definition);
+    $this->localTaskManager = $local_task_manager;
+  }
+
+  /**
    * {@inheritdoc}
    */
   public static function create(ContainerInterface $container, array $configuration, $plugin_id, $plugin_definition) {
     return new static(
       $configuration,
       $plugin_id,
-      $plugin_definition
+      $plugin_definition,
+      $container->get('plugin.manager.menu.local_task')
     );
   }
 
@@ -56,13 +83,17 @@ public function build() {
 
     // Add only selected levels for the printed output.
     if ($config['primary']) {
+      $links = $this->localTaskManager->getLocalTasks(0);
+      // Do not display single tabs.
       $tabs += [
-        '#primary' => menu_primary_local_tasks(),
+        '#primary' => count(Element::getVisibleChildren($links['tabs'])) > 1 ? $links['tabs'] : [],
       ];
     }
     if ($config['secondary']) {
+      $links = $this->localTaskManager->getLocalTasks(1);
+      // Do not display single tabs.
       $tabs += [
-        '#secondary' => menu_secondary_local_tasks(),
+        '#secondary' => count(Element::getVisibleChildren($links['tabs'])) > 1 ? $links['tabs'] : [],
       ];
     }
 
diff --git a/core/modules/system/tests/modules/menu_test/menu_test.module b/core/modules/system/tests/modules/menu_test/menu_test.module
index 429b357..60c926f 100644
--- a/core/modules/system/tests/modules/menu_test/menu_test.module
+++ b/core/modules/system/tests/modules/menu_test/menu_test.module
@@ -27,9 +27,9 @@ function menu_test_menu_links_discovered_alter(&$links) {
 }
 
 /**
- * Implements hook_menu_local_tasks().
+ * Implements hook_menu_local_tasks_alter().
  */
-function menu_test_menu_local_tasks(&$data, $route_name) {
+function menu_test_menu_local_tasks_alter(&$data, $route_name) {
   if (in_array($route_name, array('menu_test.tasks_default'))) {
     $data['tabs'][0]['foo'] = array(
       '#theme' => 'menu_local_task',
@@ -51,32 +51,6 @@ function menu_test_menu_local_tasks(&$data, $route_name) {
 }
 
 /**
- * Implements hook_menu_local_tasks_alter().
- *
- * If the menu_test.settings configuration 'tasks.alter' has been set, adds
- * several local tasks to menu-test/tasks.
- */
-function menu_test_menu_local_tasks_alter(&$data, $route_name) {
-  if (!\Drupal::config('menu_test.settings')->get('tasks.alter')) {
-    return;
-  }
-  if (in_array($route_name, array('menu_test.tasks_default', 'menu_test.tasks_empty', 'menu_test.tasks_tasks'))) {
-    // Rename the default local task from 'View' to 'Show'.
-    // $data['tabs'] is expected to be keyed by link hrefs.
-    // The default local task always links to its parent path, which means that
-    // if the tab root path appears as key in $data['tabs'], then that key is
-    // the default local task.
-    $key = $route_name . '_tab';
-    if (isset($data['tabs'][0][$key])) {
-      $data['tabs'][0][$key]['#link']['title'] = 'Show it';
-    }
-    // Rename the 'foo' task to "Advanced settings" and put it last.
-    $data['tabs'][0]['foo']['#link']['title'] = 'Advanced settings';
-    $data['tabs'][0]['foo']['#weight'] = 110;
-  }
-}
-
-/**
  * Page callback: Tests the theme negotiation functionality.
  *
  * @param bool $inherited