diff --git a/core/includes/menu.inc b/core/includes/menu.inc
index 07792cd..0174882 100644
--- a/core/includes/menu.inc
+++ b/core/includes/menu.inc
@@ -273,7 +273,7 @@
  * what the menu blocks offer you. If that's the case, you'll want to:
  * - Instantiate \Drupal\Core\Menu\MenuTreeParameters, and set its values to
  *   match your needs. Alternatively, you can use
- *   MenuLinkTree::getDefaultRenderedMenuTreeLinkParameters() to get a typical
+ *   MenuLinkTree::getCurrentRouteMenuTreeParameters() to get a typical
  *   default set of parameters, and then customize them to suit your needs.
  * - Call \Drupal\Core\MenuLinkTree::load() with your menu link tree parameters,
  *   this will return a menu link tree.
@@ -500,7 +500,7 @@ function _menu_get_links_source($name, $default) {
 function menu_navigation_links($menu_name, $level = 0) {
   /** @var \Drupal\Core\Menu\MenuLinkTreeInterface $menu_tree */
   $menu_tree = \Drupal::service('menu.link_tree');
-  $parameters = $menu_tree->getDefaultRenderedMenuTreeLinkParameters($menu_name);
+  $parameters = $menu_tree->getCurrentRouteMenuTreeParameters($menu_name);
   $parameters->setMaxDepth($level + 1);
   $tree = $menu_tree->load($menu_name, $parameters);
   $manipulators = array(
diff --git a/core/lib/Drupal/Core/Menu/DefaultMenuLinkTreeManipulators.php b/core/lib/Drupal/Core/Menu/DefaultMenuLinkTreeManipulators.php
index 266ee8e..2238a75 100644
--- a/core/lib/Drupal/Core/Menu/DefaultMenuLinkTreeManipulators.php
+++ b/core/lib/Drupal/Core/Menu/DefaultMenuLinkTreeManipulators.php
@@ -1,5 +1,10 @@
 <?php
 
+/**
+ * @file
+ * Contains \Drupal\Core\Menu\DefaultMenuLinkTreeManipulators.
+ */
+
 namespace Drupal\Core\Menu;
 
 use Drupal\Core\Access\AccessManager;
@@ -110,7 +115,6 @@ public function generateIndexAndSort(array $tree) {
       if ($tree[$key]->subtree) {
         $tree[$key]->subtree = $this->generateIndexAndSort($tree[$key]->subtree);
       }
-      /** @var \Drupal\Core\Menu\MenuLinkInterface $instance */
       $instance = $tree[$key]->link;
       // The weights are made a uniform 5 digits by adding 50000 as an offset.
       // After $this->menuLinkCheckAccess(), $instance->getTitle() has the
diff --git a/core/lib/Drupal/Core/Menu/MenuLinkTree.php b/core/lib/Drupal/Core/Menu/MenuLinkTree.php
index 7f1bed4..baaac0c 100644
--- a/core/lib/Drupal/Core/Menu/MenuLinkTree.php
+++ b/core/lib/Drupal/Core/Menu/MenuLinkTree.php
@@ -76,7 +76,7 @@ public function __construct(MenuTreeStorageInterface $tree_storage, MenuLinkMana
   /**
    * {@inheritdoc}
    */
-  public function getDefaultRenderedMenuTreeLinkParameters($menu_name) {
+  public function getCurrentRouteMenuTreeParameters($menu_name) {
     $active_trail = $this->menuActiveTrail->getActiveTrailIds($menu_name);
 
     $parameters = new MenuTreeParameters();
diff --git a/core/lib/Drupal/Core/Menu/MenuLinkTreeElement.php b/core/lib/Drupal/Core/Menu/MenuLinkTreeElement.php
index beb6446..db5cbc9 100644
--- a/core/lib/Drupal/Core/Menu/MenuLinkTreeElement.php
+++ b/core/lib/Drupal/Core/Menu/MenuLinkTreeElement.php
@@ -89,8 +89,13 @@ class MenuLinkTreeElement {
    * @param \Drupal\Core\Menu\MenuLinkInterface $link
    *   The menu link for this element in the menu link tree.
    * @param bool $has_children
+   *   A flag as to whether this element has children even if they are not
+   *   included in the tree (i.e. this may be TRUE even if $subtree is empty).
    * @param int $depth
+   *   The depth of this element relative to the tree root.
    * @param bool $in_active_trail
+   *   A flag as to whether this link was included in the list of active trail
+   *  IDs used to build the tree.
    * @param \Drupal\Core\Menu\MenuLinkTreeElement[] $subtree
    *   The children of this element in the menu link tree.
    */
diff --git a/core/lib/Drupal/Core/Menu/MenuLinkTreeInterface.php b/core/lib/Drupal/Core/Menu/MenuLinkTreeInterface.php
index 7e99998..df983fe 100644
--- a/core/lib/Drupal/Core/Menu/MenuLinkTreeInterface.php
+++ b/core/lib/Drupal/Core/Menu/MenuLinkTreeInterface.php
@@ -20,7 +20,7 @@
  * language.
  * Which links are loaded can be specified in the menu link tree parameters that
  * passed to ::load(). You can build your own set of parameter, but you can also
- * start from a typical default (::getDefaultRenderedMenuTreeLinkParameters()).
+ * start from a typical default (::getCurrentRouteMenuTreeParameters()).
  *
  * @see \Drupal\Core\Menu\MenuLinkTreeParameters
  *
@@ -56,10 +56,10 @@
    *   The menu name, needed for retrieving the active trail and links with the
    *   'expanded' flag enabled.
    *
-   * @return \Drupal\Core\Menu\MenuTreeParameters $parameters
+   * @return \Drupal\Core\Menu\MenuTreeParameters
    *   The parameters to determine which menu links to be loaded into a tree.
    */
-  public function getDefaultRenderedMenuTreeLinkParameters($menu_name);
+  public function getCurrentRouteMenuTreeParameters($menu_name);
 
   /**
    * Loads a menu tree with a menu link plugin instance at each element.
diff --git a/core/lib/Drupal/Core/Menu/MenuParentFormSelector.php b/core/lib/Drupal/Core/Menu/MenuParentFormSelector.php
index 6732a1a..ae22631 100644
--- a/core/lib/Drupal/Core/Menu/MenuParentFormSelector.php
+++ b/core/lib/Drupal/Core/Menu/MenuParentFormSelector.php
@@ -27,6 +27,14 @@ class MenuParentFormSelector implements MenuParentFormSelectorInterface {
    */
   protected $entityManager;
 
+  /**
+   * Constructs a \Drupal\Core\Menu\MenuParentFormSelector
+   *
+   * @param MenuLinkTreeInterface $menu_link_tree
+   *   The menu link tree service.
+   * @param EntityManagerInterface $entity_manager
+   *   The entity manager.
+   */
   public function __construct(MenuLinkTreeInterface $menu_link_tree, EntityManagerInterface $entity_manager) {
     $this->menuLinkTree = $menu_link_tree;
     $this->entityManager = $entity_manager;
@@ -61,7 +69,7 @@ public function getParentSelectOptions($id = '', array $menus = NULL) {
   /**
    * {@inheritdoc}
    */
-  public function parentSelectElement($menu_parent, $id = '', array $menus =  NULL) {
+  public function parentSelectElement($menu_parent, $id = '', array $menus = NULL) {
     $options = $this->getParentSelectOptions($id, $menus);
     // If no options were found, there is nothing to select.
     if ($options) {
@@ -103,7 +111,7 @@ protected function getParentDepthLimit($id) {
   /**
    * Iterates over all items in the tree to prepare the parents select options.
    *
-   * @param array $tree
+   * @param \Drupal\Core\Menu\MenuLinkTreeElement[] $tree
    *   The menu tree.
    * @param string $menu_name
    *   The menu name.
@@ -122,7 +130,6 @@ protected function parentSelectOptionsTreeWalk(array $tree, $menu_name, $indent,
         // Don't iterate through any links on this level.
         break;
       }
-      /** @var \Drupal\Core\Menu\MenuLinkInterface $link */
       $link = $element->link;
       if ($link->getPluginId() != $exclude) {
         $title = $indent . ' ' . Unicode::truncate($link->getTitle(), 30, TRUE, FALSE);
diff --git a/core/lib/Drupal/Core/Menu/MenuParentFormSelectorInterface.php b/core/lib/Drupal/Core/Menu/MenuParentFormSelectorInterface.php
index d88bcba..fdcc4b6 100644
--- a/core/lib/Drupal/Core/Menu/MenuParentFormSelectorInterface.php
+++ b/core/lib/Drupal/Core/Menu/MenuParentFormSelectorInterface.php
@@ -53,4 +53,4 @@ public function getParentSelectOptions($id = '', array $menus = NULL);
    */
   public function parentSelectElement($menu_parent, $id = '', array $menus = NULL);
 
-} 
\ No newline at end of file
+}
diff --git a/core/lib/Drupal/Core/Menu/MenuTreeStorage.php b/core/lib/Drupal/Core/Menu/MenuTreeStorage.php
index b2d5c5c..5367622 100644
--- a/core/lib/Drupal/Core/Menu/MenuTreeStorage.php
+++ b/core/lib/Drupal/Core/Menu/MenuTreeStorage.php
@@ -55,7 +55,7 @@ class MenuTreeStorage implements MenuTreeStorageInterface {
   protected $options = array();
 
   /**
-   * Stores the definitions that have already been loaded for better performance.
+   * Stores definitions that have already been loaded for better performance.
    */
   protected $definitions = array();
 
@@ -570,7 +570,17 @@ protected function updateParentalStatus(array $link) {
     }
   }
 
-  protected function prepareLink($link, $intersect = FALSE) {
+  /**
+   * Prepare a link by unserializing values and saving the definition.
+   *
+   * @param array $link
+   *   The data loaded in the query.
+   * @param bool $intersect
+   *   If TRUE, filter out values that are not part of the actual definition.
+   * @return array
+   *   The prepared link data.
+   */
+  protected function prepareLink(array $link, $intersect = FALSE) {
     foreach ($this->serializedFields() as $name) {
       $link[$name] = unserialize($link[$name]);
     }
@@ -789,6 +799,7 @@ public function loadTreeData($menu_name, MenuTreeParameters $parameters) {
    *   The parameters to determine which menu links to be loaded into a tree.
    *   ::loadLinks() will set the absolute minimum depth, which is used
    *   ::doBuildTreeData().
+   *
    * @return array
    *   A flat array of menu links that are part of the menu. Each array element
    *   is an associative array of information about the menu link, containing
@@ -1035,8 +1046,8 @@ protected function treeDataRecursive(array &$links, array $parents, $depth) {
       $tree[$tree_link_definition['id']] = array(
         'definition' => $this->prepareLink($tree_link_definition, TRUE),
         'has_children' => $tree_link_definition['has_children'],
-        // We need to determine if we're on the path to root so we can later build
-        // the correct active trail.
+        // We need to determine if we're on the path to root so we can later
+        // build the correct active trail.
         'in_active_trail' => in_array($tree_link_definition['id'], $parents),
         'subtree' => array(),
         'depth' => $tree_link_definition['depth'],
diff --git a/core/modules/menu_link_content/src/Tests/MenuLinkContentUITest.php b/core/modules/menu_link_content/src/Tests/MenuLinkContentUITest.php
index 6d2bed0..052495a 100644
--- a/core/modules/menu_link_content/src/Tests/MenuLinkContentUITest.php
+++ b/core/modules/menu_link_content/src/Tests/MenuLinkContentUITest.php
@@ -19,7 +19,12 @@ class MenuLinkContentUITest extends ContentTranslationUITest {
    *
    * @var array
    */
-  public static $modules = array('language', 'content_translation', 'menu_link_content', 'menu_ui');
+  public static $modules = array(
+    'language',
+    'content_translation',
+    'menu_link_content',
+    'menu_ui',
+  );
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/system/src/Plugin/Block/SystemMenuBlock.php b/core/modules/system/src/Plugin/Block/SystemMenuBlock.php
index d2f9e84..9a93288 100644
--- a/core/modules/system/src/Plugin/Block/SystemMenuBlock.php
+++ b/core/modules/system/src/Plugin/Block/SystemMenuBlock.php
@@ -79,7 +79,7 @@ public static function create(ContainerInterface $container, array $configuratio
    */
   public function build() {
     $menu_name = $this->getDerivativeId();
-    $parameters = $this->menuTree->getDefaultRenderedMenuTreeLinkParameters($menu_name);
+    $parameters = $this->menuTree->getCurrentRouteMenuTreeParameters($menu_name);
     $tree = $this->menuTree->load($menu_name, $parameters);
     $manipulators = array(
       array('callable' => 'menu.default_tree_manipulators:checkAccess'),
diff --git a/core/modules/system/src/Tests/Menu/MenuLinkTreeTest.php b/core/modules/system/src/Tests/Menu/MenuLinkTreeTest.php
index 4b2af79..86b72ec 100644
--- a/core/modules/system/src/Tests/Menu/MenuLinkTreeTest.php
+++ b/core/modules/system/src/Tests/Menu/MenuLinkTreeTest.php
@@ -38,7 +38,12 @@ class MenuLinkTreeTest extends KernelTestBase {
    *
    * @var array
    */
-  public static $modules = array('system', 'menu_test', 'menu_link_content', 'field');
+  public static $modules = array(
+    'system',
+    'menu_test',
+    'menu_link_content',
+    'field',
+  );
 
   /**
    * {@inheritdoc}
@@ -90,6 +95,9 @@ public function testDeleteLinksInMenu() {
     $this->assertEqual(count($output), 1);
   }
 
+  /**
+   * Tests creating links with an expected tree structure.
+   */
   public function testCreateLinksInMenu() {
     /**
      * This creates a tree with the following structure:
diff --git a/core/modules/system/src/Tests/Menu/MenuTreeStorageTest.php b/core/modules/system/src/Tests/Menu/MenuTreeStorageTest.php
index 0df4c1e..8064984 100644
--- a/core/modules/system/src/Tests/Menu/MenuTreeStorageTest.php
+++ b/core/modules/system/src/Tests/Menu/MenuTreeStorageTest.php
@@ -133,7 +133,7 @@ public function testMenuLinkMoving() {
 
     $this->assertMenuLink('test1', array('has_children' => 1, 'depth' => 1), array(), array('test2', 'test3'));
     $this->assertMenuLink('test2', array('has_children' => 1, 'depth' => 2), array('test1'), array('test3'));
-    $this->assertMenuLink('test4', array('has_children' => 1, 'depth' => 1), array(),  array('test5', 'test6'));
+    $this->assertMenuLink('test4', array('has_children' => 1, 'depth' => 1), array(), array('test5', 'test6'));
     $this->assertMenuLink('test5', array('has_children' => 1, 'depth' => 2), array('test4'), array('test6'));
     $this->assertMenuLink('test6', array('has_children' => 0, 'depth' => 3), array('test5', 'test4'));
 
@@ -391,8 +391,8 @@ protected function assertMenuLink($id, array $expected_properties, array $parent
     $found_children = array_keys($this->treeStorage->loadAllChildren($id));
     // We need both these checks since the 2nd will pass if there are extra
     // IDs loaded in $found_children.
-    $this->assertEqual(count($children), count($found_children)); //, "Found expected number of children for $id");
-    $this->assertEqual(array_intersect($children, $found_children), $children); //, 'Child IDs match');
+    $this->assertEqual(count($children), count($found_children), "Found expected number of children for $id");
+    $this->assertEqual(array_intersect($children, $found_children), $children, 'Child IDs match');
   }
 
 }
diff --git a/core/tests/Drupal/Tests/Core/Menu/DefaultMenuLinkTreeManipulatorsTest.php b/core/tests/Drupal/Tests/Core/Menu/DefaultMenuLinkTreeManipulatorsTest.php
index 8962271..e536f2c 100644
--- a/core/tests/Drupal/Tests/Core/Menu/DefaultMenuLinkTreeManipulatorsTest.php
+++ b/core/tests/Drupal/Tests/Core/Menu/DefaultMenuLinkTreeManipulatorsTest.php
@@ -79,6 +79,8 @@ protected function setUp() {
   }
 
   /**
+   * Helper function to create a mock tree.
+   *
    * This mocks a tree with the following structure:
    * - 1
    * - 2
@@ -133,9 +135,9 @@ public function testGenerateIndexAndSort() {
     $this->assertEquals($this->links[6]->getPluginId(), $tree['50000 barbar test.example6']->link->getPluginId());
     $this->assertEquals($this->links[8]->getPluginId(), $tree['50000 quxqux test.example8']->link->getPluginId());
 
-    // Validate that child element #4 exists at the correct location in the hierarchy.
+    // Verify that child element #4 is at the correct location in the hierarchy.
     $this->assertEquals($this->links[4]->getPluginId(), $tree['50000 bar test.example2']->subtree['50000 baz test.example3']->subtree['50000 qux test.example4']->link->getPluginId());
-    // Validate that child element #7 exists at the correct location in the hierarchy.
+    // Verify that child element #7 is at the correct location in the hierarchy.
     $this->assertEquals($this->links[7]->getPluginId(), $tree['50000 foofoo test.example5']->subtree['50000 bazbaz test.example7']->link->getPluginId());
   }