diff --git a/core/lib/Drupal/Core/Entity/DatabaseStorageControllerNG.php b/core/lib/Drupal/Core/Entity/DatabaseStorageControllerNG.php
index 9b7020a..45ae1e6 100644
--- a/core/lib/Drupal/Core/Entity/DatabaseStorageControllerNG.php
+++ b/core/lib/Drupal/Core/Entity/DatabaseStorageControllerNG.php
@@ -275,6 +275,12 @@ public function save(EntityInterface $entity) {
       // Ensure we are dealing with the actual entity.
       $entity = $entity->getNGEntity();
 
+      // There are some cases that pre-set ->original for performance. Make sure
+      // original is not a BC decorator.
+      if ($entity->original instanceof \Drupal\Core\Entity\EntityBCDecorator) {
+        $entity->original = $entity->original->getNGEntity();
+      }
+
       // Sync the changes made in the fields array to the internal values array.
       $entity->updateOriginalValues();
 
diff --git a/core/lib/Drupal/Core/Entity/Entity.php b/core/lib/Drupal/Core/Entity/Entity.php
index 37311dc..e1abc47 100644
--- a/core/lib/Drupal/Core/Entity/Entity.php
+++ b/core/lib/Drupal/Core/Entity/Entity.php
@@ -10,6 +10,7 @@
 use Drupal\Component\Uuid\Uuid;
 use Drupal\Core\Language\Language;
 use Drupal\Core\TypedData\TypedDataInterface;
+use Drupal\user\UserInterface;
 use IteratorAggregate;
 
 /**
@@ -257,7 +258,7 @@ public function getIterator() {
   /**
    * Implements \Drupal\Core\TypedData\AccessibleInterface::access().
    */
-  public function access($operation = 'view', \Drupal\user\UserInterface $account = NULL) {
+  public function access($operation = 'view', UserInterface $account = NULL) {
     return \Drupal::entityManager()
       ->getAccessController($this->entityType)
       ->access($this, $operation, LANGUAGE_DEFAULT, $account);
diff --git a/core/lib/Drupal/Core/TypedData/AccessibleInterface.php b/core/lib/Drupal/Core/TypedData/AccessibleInterface.php
index 40b4645..a268573 100644
--- a/core/lib/Drupal/Core/TypedData/AccessibleInterface.php
+++ b/core/lib/Drupal/Core/TypedData/AccessibleInterface.php
@@ -7,6 +7,8 @@
 
 namespace Drupal\Core\TypedData;
 
+use Drupal\user\UserInterface;
+
 /**
  * Interface for checking access.
  */
@@ -32,6 +34,6 @@
    *
    * @todo Don't depend on module level code.
    */
-  public function access($operation = 'view', \Drupal\user\UserInterface $account = NULL);
+  public function access($operation = 'view', UserInterface $account = NULL);
 
 }
diff --git a/core/modules/system/lib/Drupal/system/Tests/Plugin/PluginTestBase.php b/core/modules/system/lib/Drupal/system/Tests/Plugin/PluginTestBase.php
index 7b8aa9a..57869c4 100644
--- a/core/modules/system/lib/Drupal/system/Tests/Plugin/PluginTestBase.php
+++ b/core/modules/system/lib/Drupal/system/Tests/Plugin/PluginTestBase.php
@@ -74,7 +74,7 @@ public function setUp() {
         'label' => 'User name',
         'class' => 'Drupal\plugin_test\Plugin\plugin_test\mock_block\MockUserNameBlock',
         'context' => array(
-          'user' => array('class' => 'Drupal\user\Plugin\Core\Entity\User')
+          'user' => array('class' => 'Drupal\user\\UserInterface')
         ),
       ),
       'string_context' => array(
@@ -88,7 +88,7 @@ public function setUp() {
         'label' => 'Complex context',
         'class' => 'Drupal\plugin_test\Plugin\plugin_test\mock_block\MockComplexContextBlock',
         'context' => array(
-          'user' => array('class' => 'Drupal\user\Plugin\Core\Entity\User'),
+          'user' => array('class' => 'Drupal\user\\UserInterface'),
           'node' => array('class' => 'Drupal\Core\Entity\EntityBCDecorator'),
         ),
       ),
diff --git a/core/modules/user/lib/Drupal/user/AccountFormController.php b/core/modules/user/lib/Drupal/user/AccountFormController.php
index db12835..c820f67 100644
--- a/core/modules/user/lib/Drupal/user/AccountFormController.php
+++ b/core/modules/user/lib/Drupal/user/AccountFormController.php
@@ -225,7 +225,7 @@ public function form(array $form, array &$form_state) {
   }
 
   /**
-   * Overrides Drupal\Core\Entity\EntityFormController::buildEntity().
+   * {@inheritdoc}
    */
   public function buildEntity(array $form, array &$form_state) {
     // Change the roles array to a list of enabled roles.
diff --git a/core/modules/user/lib/Drupal/user/Plugin/Core/Entity/User.php b/core/modules/user/lib/Drupal/user/Plugin/Core/Entity/User.php
index b338eef..5a92181 100644
--- a/core/modules/user/lib/Drupal/user/Plugin/Core/Entity/User.php
+++ b/core/modules/user/lib/Drupal/user/Plugin/Core/Entity/User.php
@@ -193,12 +193,15 @@ class User extends EntityNG implements UserInterface {
   );
 
   /**
-   * Implements Drupal\Core\Entity\EntityInterface::id().
+   * {@inheritdoc}
    */
   public function id() {
     return $this->get('uid')->value;
   }
 
+  /**
+   * {@inheritdoc}
+   */
   protected function init() {
     parent::init();
     unset($this->access);
@@ -220,6 +223,9 @@ protected function init() {
     unset($this->uuid);
   }
 
+  /**
+   * {@inheritdoc}
+   */
   public function getBCEntity() {
     if (!isset($this->bcEntity)) {
       // Initialize field definitions so that we can pass them by reference.
@@ -229,5 +235,4 @@ public function getBCEntity() {
     return $this->bcEntity;
   }
 
-
 }
diff --git a/core/modules/user/lib/Drupal/user/UserStorageController.php b/core/modules/user/lib/Drupal/user/UserStorageController.php
index 816511b..85acfa3 100644
--- a/core/modules/user/lib/Drupal/user/UserStorageController.php
+++ b/core/modules/user/lib/Drupal/user/UserStorageController.php
@@ -65,12 +65,6 @@ public function save(EntityInterface $entity) {
       $entity->uid->value = db_next_id(db_query('SELECT MAX(uid) FROM {users}')->fetchField());
       $entity->enforceIsNew();
     }
-
-    // There are some cases that pre-set ->original for performance. Make sure
-    // original is not a BC decorator.
-    if ($entity->original instanceof \Drupal\Core\Entity\EntityBCDecorator) {
-      $entity->original = $entity->original->getNGEntity();
-    }
     parent::save($entity);
   }
 
@@ -114,15 +108,12 @@ protected function postSave(EntityInterface $entity, $update) {
       // user and recreate the current one.
       if ($entity->pass->value != $entity->original->pass->value) {
         drupal_session_destroy_uid($entity->id());
-        if ($entity->uid->value == $GLOBALS['user']->uid) {
+        if ($entity->id() == $GLOBALS['user']->uid) {
           drupal_session_regenerate();
         }
       }
 
-      // Remove roles that are no longer enabled for the user.
-      //$entity->roles = array_filter($entity->roles);
-
-      // Reload user roles if provided.
+      // Update user roles if changed.
       if ($entity->roles->getValue() != $entity->original->roles->getValue()) {
         db_delete('users_roles')
           ->condition('uid', $entity->id())
@@ -180,7 +171,7 @@ protected function postDelete($entities) {
   }
 
   /**
-   * Overrides \Drupal\Core\Entity\DataBaseStorageControllerNG::invokeHook().
+   * {@inheritdoc}
    */
   protected function invokeHook($hook, EntityInterface $entity) {
     $function = 'field_attach_' . $hook;
@@ -194,13 +185,13 @@ protected function invokeHook($hook, EntityInterface $entity) {
     }
 
     // Invoke the hook.
-    module_invoke_all($this->entityType . '_' . $hook, $entity->getBCEntity());
+    \Drupal::moduleHandler()->invokeAll($this->entityType . '_' . $hook, $entity->getBCEntity());
     // Invoke the respective entity-level hook.
-    module_invoke_all('entity_' . $hook, $entity->getBCEntity(), $this->entityType);
+    \Drupal::moduleHandler()->invokeAll('entity_' . $hook, $entity->getBCEntity(), $this->entityType);
   }
 
   /**
-   * Overrides \Drupal\Core\Entity\DataBaseStorageControllerNG::baseFieldDefinitions().
+   * {@inheritdoc}
    */
   public function baseFieldDefinitions() {
     $properties['uid'] = array(