diff -u b/core/lib/Drupal/Core/Entity/EntityManager.php b/core/lib/Drupal/Core/Entity/EntityManager.php
--- b/core/lib/Drupal/Core/Entity/EntityManager.php
+++ b/core/lib/Drupal/Core/Entity/EntityManager.php
@@ -484,38 +484,37 @@
   /**
    * {@inheritdoc}
    */
-  public function getExtraFields($entity_type, $bundle) {
+  public function getExtraFields($entity_type_id, $bundle) {
     // Read from the "static" cache.
-    if (isset($this->bundleExtraFields[$entity_type][$bundle])) {
-      return $this->bundleExtraFields[$entity_type][$bundle];
+    if (isset($this->bundleExtraFields[$entity_type_id][$bundle])) {
+      return $this->bundleExtraFields[$entity_type_id][$bundle];
     }
 
     // Read from the persistent cache. Since hook_entity_extra_field_info() and
     // hook_entity_extra_field_info_alter() might contain t() calls, we cache
     // per language.
-    $langcode = $this->languageManager->getCurrentLanguage()->id;
-    $cache_id = "entity_bundle_extra_fields:$langcode:$entity_type:$bundle";
+    $cache_id = 'entity_bundle_extra_fields:' . $entity_type_id . ':' . $bundle . ':' . $this->languageManager->getCurrentLanguage()->id;
     $cached = $this->cache->get($cache_id);
     if ($cached) {
-      $this->bundleExtraFields[$entity_type][$bundle] = $cached->data;
-      return $this->bundleExtraFields[$entity_type][$bundle];
+      $this->bundleExtraFields[$entity_type_id][$bundle] = $cached->data;
+      return $this->bundleExtraFields[$entity_type_id][$bundle];
     }
 
     $extra = $this->moduleHandler->invokeAll('entity_extra_field_info');
     $this->moduleHandler->alter('entity_extra_field_info', $extra);
-    $info = isset($extra[$entity_type][$bundle]) ? $extra[$entity_type][$bundle] : array();
+    $info = isset($extra[$entity_type_id][$bundle]) ? $extra[$entity_type_id][$bundle] : array();
     $info += array(
       'form' => array(),
       'display' => array(),
     );
 
     // Store in the 'static' and persistent caches.
-    $this->bundleExtraFields[$entity_type][$bundle] = $info;
+    $this->bundleExtraFields[$entity_type_id][$bundle] = $info;
     $this->cache->set($cache_id, $info, Cache::PERMANENT, array(
       'entity_field_info' => TRUE,
     ));
 
-    return $this->bundleExtraFields[$entity_type][$bundle];
+    return $this->bundleExtraFields[$entity_type_id][$bundle];
   }
 
   /**
diff -u b/core/lib/Drupal/Core/Entity/EntityManagerInterface.php b/core/lib/Drupal/Core/Entity/EntityManagerInterface.php
--- b/core/lib/Drupal/Core/Entity/EntityManagerInterface.php
+++ b/core/lib/Drupal/Core/Entity/EntityManagerInterface.php
@@ -189,15 +189,31 @@
   /**
    * Retrieves the "extra fields" for a bundle.
    *
-   * @param string $entity_type
-   *   The entity type.
+   * @param string $entity_type_id
+   *   The entity type ID.
    * @param string $bundle
    *   The bundle name.
    *
    * @return array
-   *   The array of extra fields.
+   *   A nested array of 'pseudo-field' elements. Each list is nested within the
+   *   following keys: entity type, bundle name, context (either 'form' or
+   *   'display'). The keys are the name of the elements as appearing in the
+   *   renderable array (either the entity form or the displayed entity). The
+   *   value is an associative array:
+   *   - label: The human readable name of the element. Make sure you sanitize
+   *     this appropriately.
+   *   - description: A short description of the element contents.
+   *   - weight: The default weight of the element.
+   *   - visible: (optional) The default visibility of the element. Defaults to
+   *     TRUE.
+   *   - edit: (optional) String containing markup (normally a link) used as the
+   *     element's 'edit' operation in the administration interface. Only for
+   *     'form' context.
+   *   - delete: (optional) String containing markup (normally a link) used as the
+   *     element's 'delete' operation in the administration interface. Only for
+   *     'form' context.
    */
-  public function getExtraFields($entity_type, $bundle);
+  public function getExtraFields($entity_type_id, $bundle);
 
   /**
    * Returns the entity translation to be used in the given context.
diff -u b/core/modules/field/lib/Drupal/field/Tests/FieldInfoTest.php b/core/modules/field/lib/Drupal/field/Tests/FieldInfoTest.php
--- b/core/modules/field/lib/Drupal/field/Tests/FieldInfoTest.php
+++ b/core/modules/field/lib/Drupal/field/Tests/FieldInfoTest.php
@@ -363,6 +363,41 @@
     );
   }
 
+  /**
+   * Tests that the extra fields can be translated.
+   */
+  function testFieldInfoExtraFieldsTranslation() {
+    $this->enableModules(array('language', 'locale'));
+    $this->installSchema('locale', array('locales_source', 'locales_target', 'locales_location'));
+    foreach (array('en', 'hu') as $id) {
+      $language = new Language(array(
+        'id' => $id,
+      ));
+      language_save($language);
+    }
+    $locale_storage = $this->container->get('locale.storage');
+
+    // Create test source string.
+    $en_string = $locale_storage->createString(array(
+      'source' => 'User name and password',
+      'context' => '',
+    ))->save();
+
+    // Create translation for new string and save it.
+    $translated_string = $this->randomString();
+    $locale_storage->createTranslation(array(
+      'lid' => $en_string->lid,
+      'language' => 'hu',
+      'translation' => $translated_string,
+    ))->save();
+
+    // Check that the label is translated.
+    \Drupal::translation()->setDefaultLangcode('hu');
+    $field_info = \Drupal::service('field.info');
+    $user_fields = $field_info->getBundleExtraFields('user', 'user');
+    $this->assertEqual($user_fields['form']['account']['label'], $translated_string);
+  }
+
 }
     $translated_string = $this->randomString();
     $locale_storage->createTranslation(array(
@@ -380,2 +415,37 @@
 
+  /**
+   * Tests that the extra fields can be translated.
+   */
+  function testFieldInfoExtraFieldsTranslation() {
+    $this->enableModules(array('language', 'locale'));
+    $this->installSchema('locale', array('locales_source', 'locales_target', 'locales_location'));
+    foreach (array('en', 'hu') as $id) {
+      $language = new Language(array(
+        'id' => $id,
+      ));
+      language_save($language);
+    }
+    $locale_storage = $this->container->get('locale.storage');
+
+    // Create test source string.
+    $en_string = $locale_storage->createString(array(
+      'source' => 'User name and password',
+      'context' => '',
+    ))->save();
+
+    // Create translation for new string and save it.
+    $translated_string = $this->randomString();
+    $locale_storage->createTranslation(array(
+      'lid' => $en_string->lid,
+      'language' => 'hu',
+      'translation' => $translated_string,
+    ))->save();
+
+    // Check that the label is translated.
+    \Drupal::translation()->setDefaultLangcode('hu');
+    $field_info = \Drupal::service('field.info');
+    $user_fields = $field_info->getBundleExtraFields('user', 'user');
+    $this->assertEqual($user_fields['form']['account']['label'], $translated_string);
+  }
+
 }
diff -u b/core/modules/system/entity.api.php b/core/modules/system/entity.api.php
--- b/core/modules/system/entity.api.php
+++ b/core/modules/system/entity.api.php
@@ -820,7 +820,6 @@
  *     (\Drupal\Core\Field\FieldItemListInterface).
  */
 function hook_entity_field_access_alter(array &$grants, array $context) {
-  /** @var \Drupal\Core\Field\FieldDefinitionInterface $field_definition */
   $field_definition = $context['field_definition'];
   if ($field_definition->getName() == 'field_of_interest' && $grants['node'] === FALSE) {
     // Override node module's restriction to no opinion. We don't want to
@@ -843,6 +842,7 @@
  *     (\Drupal\Core\Field\FieldItemListInterface).
  */
 function hook_entity_field_access_alter(array &$grants, array $context) {
+  /** @var \Drupal\Core\Field\FieldDefinitionInterface $field_definition */
   $field_definition = $context['field_definition'];
   if ($field_definition->getName() == 'field_of_interest' && $grants['node'] === FALSE) {
     // Override node module's restriction to no opinion. We don't want to
@@ -855,38 +855,22 @@
 }
 
 /**
- * Exposes "pseudo-field" components on fieldable entities.
+ * Exposes "pseudo-field" components on content entities.
  *
  * Field UI's "Manage fields" and "Manage display" pages let users re-order
  * fields, but also non-field components. For nodes, these include the title
  * and other elements exposed by modules through hook_form_alter().
  *
- * Fieldable entities or modules that want to have their components supported
+ * Content entities or modules that want to have their components supported
  * should expose them using this hook. The user-defined settings (weight,
- * visible) are automatically applied on rendered forms and displayed entities
- * in a #pre_render callback added by field_attach_form() and
- * EntityViewBuilder::viewMultiple().
+ * visible) are automatically applied when entities or entity forms are
+ * rendered.
  *
  * @see hook_entity_extra_field_info_alter()
  *
  * @return array
- *   A nested array of 'pseudo-field' elements. Each list is nested within the
- *   following keys: entity type, bundle name, context (either 'form' or
- *   'display'). The keys are the name of the elements as appearing in the
- *   renderable array (either the entity form or the displayed entity). The
- *   value is an associative array:
- *   - label: The human readable name of the element. Make sure you sanitize
- *     this appropriately.
- *   - description: A short description of the element contents.
- *   - weight: The default weight of the element.
- *   - visible: (optional) The default visibility of the element. Defaults to
- *     TRUE.
- *   - edit: (optional) String containing markup (normally a link) used as the
- *     element's 'edit' operation in the administration interface. Only for
- *     'form' context.
- *   - delete: (optional) String containing markup (normally a link) used as the
- *     element's 'delete' operation in the administration interface. Only for
- *     'form' context.
+ *  The array structure is identical to that of the return value of
+ *  \Drupal\Core\Entity\EntityManagerInterface::getExtraFields().
  */
 function hook_entity_extra_field_info() {
   $extra = array();
@@ -930,8 +914,9 @@
 /**
  * Alter "pseudo-field" components on fieldable entities.
  *
- * @param $info
- *   The associative array of 'pseudo-field' components.
+ * @param array $info
+ *  The array structure is identical to that of the return value of
+ *  \Drupal\Core\Entity\EntityManagerInterface::getExtraFields().
  *
  * @see hook_entity_extra_field_info()
  */
diff -u b/core/tests/Drupal/Tests/Core/Entity/EntityManagerTest.php b/core/tests/Drupal/Tests/Core/Entity/EntityManagerTest.php
--- b/core/tests/Drupal/Tests/Core/Entity/EntityManagerTest.php
+++ b/core/tests/Drupal/Tests/Core/Entity/EntityManagerTest.php
@@ -786,11 +786,11 @@
   function testgetExtraFields() {
     $this->setUpEntityManager();
 
-    $entity_type = $this->randomName();
+    $entity_type_id = $this->randomName();
     $bundle = $this->randomName();
     $language_code = 'en';
     $hook_bundle_extra_fields = array(
-      $entity_type => array(
+      $entity_type_id => array(
         $bundle => array(
           'form' => array(
             'foo_extra_field' => array(
@@ -801,10 +801,10 @@
       ),
     );
     $processed_hook_bundle_extra_fields = $hook_bundle_extra_fields;
-    $processed_hook_bundle_extra_fields[$entity_type][$bundle] += array(
+    $processed_hook_bundle_extra_fields[$entity_type_id][$bundle] += array(
       'display' => array(),
     );
-    $cache_id = "entity_bundle_extra_fields:$language_code:$entity_type:$bundle";
+    $cache_id = 'entity_bundle_extra_fields:' . $entity_type_id . ':' . $bundle . ':' . $language_code;
 
     $language = new Language();
     $language->id = $language_code;
@@ -827,9 +827,9 @@
 
     $this->cache->expects($this->once())
       ->method('set')
-      ->with($cache_id, $processed_hook_bundle_extra_fields[$entity_type][$bundle]);
+      ->with($cache_id, $processed_hook_bundle_extra_fields[$entity_type_id][$bundle]);
 
-    $this->assertSame($processed_hook_bundle_extra_fields[$entity_type][$bundle], $this->entityManager->getExtraFields($entity_type, $bundle));
+    $this->assertSame($processed_hook_bundle_extra_fields[$entity_type_id][$bundle], $this->entityManager->getExtraFields($entity_type_id, $bundle));
   }
 
   /**