diff --git a/core/includes/menu.inc b/core/includes/menu.inc
index 6f2f803..04f1f30 100644
--- a/core/includes/menu.inc
+++ b/core/includes/menu.inc
@@ -213,29 +213,6 @@
  */
 
 /**
- * @defgroup menu_context_types Menu context types
- * @{
- * Flags for use in the "context" attribute of menu router items.
- */
-
-/**
- * Internal menu flag: Invisible local task.
- *
- * This flag may be used for local tasks like "Delete", so custom modules and
- * themes can alter the default context and expose the task by altering menu.
- */
-const MENU_CONTEXT_NONE = 0x0000;
-
-/**
- * Internal menu flag: Local task should be displayed in page context.
- */
-const MENU_CONTEXT_PAGE = 0x0001;
-
-/**
- * @} End of "defgroup menu_context_types".
- */
-
-/**
  * @defgroup menu_status_codes Menu status codes
  * @{
  * Status codes for menu callbacks.
@@ -305,19 +282,16 @@
 const MENU_PREFERRED_LINK = '1cf698d64d1aa4b83907cf6ed55db3a7f8e92c91';
 
 /**
- * Localizes the router item title using t() or another callback.
+ * Localizes a menu link title using t() if possible.
  *
  * Translate the title and description to allow storage of English title
  * strings in the database, yet display of them in the language required
  * by the current user.
  *
  * @param $item
- *   A menu router item or a menu link item.
- * @param $link_translate
- *   TRUE if we are translating a menu link item; FALSE if we are
- *   translating a menu router item.
+ *   A menu link entity.
  */
-function _menu_item_localize(&$item, $link_translate = FALSE) {
+function _menu_item_localize(&$item) {
   // Allow default menu links to be translated.
   $item['localized_options'] = $item['options'];
   // All 'class' attributes are assumed to be an array during rendering, but
@@ -328,22 +302,13 @@ function _menu_item_localize(&$item, $link_translate = FALSE) {
   if (isset($item['options']['attributes']['class']) && is_string($item['options']['attributes']['class'])) {
     $item['localized_options']['attributes']['class'] = explode(' ', $item['options']['attributes']['class']);
   }
-  // If we are translating the title of a menu link, and its title is the same
-  // as the corresponding router item, then we can use the title information
-  // from the router. If it's customized, then we need to use the link title
-  // itself; can't localize.
-  // If we are translating a router item (tabs, page, breadcrumb), then we
-  // can always use the information from the router item.
-  if (!$link_translate || !isset($item['link_title']) || ($item['title'] == $item['link_title'])) {
-    // t() is a special case. Since it is used very close to all the time,
-    // we handle it directly instead of using indirect, slower methods.
-    // @todo Recheck this line once https://drupal.org/node/2084421 is in.
-    $item['title'] = isset($item['link_title']) ? $item['link_title'] : $item['title'];
+  // If the menu link is defined in code and not customized, we can use t().
+  if (!empty($item['machine_name']) && !$item['customized']) {
     // @todo Figure out a proper way to support translations of menu links, see
     //   https://drupal.org/node/2193777.
-    $item['title'] = t($item['title']);
+    $item['title'] = t($item['link_title']);
   }
-  elseif ($link_translate) {
+  else {
     $item['title'] = $item['link_title'];
   }
 }
@@ -390,7 +355,7 @@ function _menu_link_translate(&$item) {
     }
     // For performance, don't localize a link the user can't access.
     if ($item['access']) {
-      _menu_item_localize($item, TRUE);
+      _menu_item_localize($item);
     }
   }
 
@@ -632,7 +597,7 @@ function menu_tree_page_data($menu_name, $max_depth = NULL, $only_active_trail =
 
   // Check if the active trail has been overridden for this menu tree.
   $active_path = menu_tree_get_path($menu_name);
-  // Load the router item corresponding to the current page.
+  // Load the request corresponding to the current page.
   $request = \Drupal::request();
   $system_path = NULL;
   if ($route_name = $request->attributes->get(RouteObjectInterface::ROUTE_NAME)) {
diff --git a/core/lib/Drupal/Core/EventSubscriber/RouterRebuildSubscriber.php b/core/lib/Drupal/Core/EventSubscriber/RouterRebuildSubscriber.php
index 0d59329..98bf05c 100644
--- a/core/lib/Drupal/Core/EventSubscriber/RouterRebuildSubscriber.php
+++ b/core/lib/Drupal/Core/EventSubscriber/RouterRebuildSubscriber.php
@@ -17,7 +17,7 @@
 use Symfony\Component\HttpKernel\KernelEvents;
 
 /**
- * Rebuilds the router and runs menu-specific code if necessary.
+ * Rebuilds the default menu links and runs menu-specific code if necessary.
  */
 class RouterRebuildSubscriber implements EventSubscriberInterface {
 
@@ -55,20 +55,20 @@ public function onKernelTerminate(PostResponseEvent $event) {
   }
 
   /**
-   * Rebuilds the menu_router and deletes the local_task cache tag.
+   * Rebuilds the menu links and deletes the local_task cache tag.
    *
    * @param \Symfony\Component\EventDispatcher\Event $event
    *   The event object.
    */
   public function onRouterRebuild(Event $event) {
-    $this->menuRouterRebuild();
+    $this->menuLinksRebuild();
     Cache::deleteTags(array('local_task' => 1));
   }
 
   /**
    * Perform menu-specific rebuilding.
    */
-  protected function menuRouterRebuild() {
+  protected function menuLinksRebuild() {
     if ($this->lock->acquire(__FUNCTION__)) {
       $transaction = db_transaction();
       try {