diff --git a/core/modules/field/field.attach.inc b/core/modules/field/field.attach.inc
index 1ca43e0..5b7f2db 100644
--- a/core/modules/field/field.attach.inc
+++ b/core/modules/field/field.attach.inc
@@ -114,8 +114,8 @@ const FIELD_STORAGE_INSERT = 'insert';
  *
  * @param string $method
  *   The name of the method to invoke.
- * @param Closure $target
- *   A closure that receives an $instance object and returns the object on
+ * @param callable $target_function
+ *   A function that receives an $instance object and returns the object on
  *   which the method should be invoked.
  * @param Drupal\Core\Entity\EntityInterface $entity
  *   The fully formed $entity_type entity.
@@ -143,7 +143,7 @@ const FIELD_STORAGE_INSERT = 'insert';
  * @return array
  *   An array of returned values.
  */
-function field_invoke_method($method, \Closure $target_closure, EntityInterface $entity, &$a = NULL, &$b = NULL, array $options = array()) {
+function field_invoke_method($method, $target_function, EntityInterface $entity, &$a = NULL, &$b = NULL, array $options = array()) {
   // Merge default options.
   $default_options = array(
     'deleted' => FALSE,
@@ -161,7 +161,7 @@ function field_invoke_method($method, \Closure $target_closure, EntityInterface
 
     // Let the closure determine the target object on which the method should be
     // called.
-    $target = $target_closure($instance);
+    $target = $target_function($instance);
 
     if (method_exists($target, $method)) {
       $field = field_info_field_by_id($instance['field_id']);
@@ -204,8 +204,8 @@ function field_invoke_method($method, \Closure $target_closure, EntityInterface
  *
  * @param string $method
  *   The name of the method to invoke.
- * @param Closure $target
- *   A closure that receives an $instance object and returns the object on
+ * @param callable $target_function
+ *   A function that receives an $instance object and returns the object on
  *   which the method should be invoked.
  * @param array $entities
  *   An array of entities, keyed by entity ID.
@@ -235,7 +235,7 @@ function field_invoke_method($method, \Closure $target_closure, EntityInterface
  *
  * @see field_invoke_method()
  */
-function field_invoke_method_multiple($method, \Closure $target, array $entities, &$a = NULL, &$b = NULL, array $options = array()) {
+function field_invoke_method_multiple($method, $target_function, array $entities, &$a = NULL, &$b = NULL, array $options = array()) {
   // Merge default options.
   $default_options = array(
     'deleted' => FALSE,
@@ -246,7 +246,7 @@ function field_invoke_method_multiple($method, \Closure $target, array $entities
   $instances = array();
   $grouped_entities = array();
   $grouped_items = array();
-  $grouped_objects = array();
+  $grouped_targets = array();
   $return = array();
 
   // Go through the entities and collect the instances on which the method
@@ -264,11 +264,11 @@ function field_invoke_method_multiple($method, \Closure $target, array $entities
 
       // Let the closure determine the target object on which the method should
       // be called.
-      if (empty($grouped_objects[$instance_id])) {
-        $grouped_objects[$instance_id] = $target($instance);
+      if (empty($grouped_targets[$instance_id])) {
+        $grouped_targets[$instance_id] = $target_function($instance);
       }
 
-      if (method_exists($grouped_objects[$instance_id], $method)) {
+      if (method_exists($grouped_targets[$instance_id], $method)) {
         // Add the instance to the list of instances to invoke the hook on.
         if (!isset($instances[$instance_id])) {
           $instances[$instance_id] = $instance;
@@ -298,7 +298,7 @@ function field_invoke_method_multiple($method, \Closure $target, array $entities
     // Iterate over all the field translations.
     foreach ($grouped_items[$instance_id] as $langcode => &$items) {
       $entities = $grouped_entities[$instance_id][$langcode];
-      $results = $grouped_objects[$instance_id]->$method($entities, $langcode, $items, $a, $b);
+      $results = $grouped_targets[$instance_id]->$method($entities, $langcode, $items, $a, $b);
 
       if (isset($results)) {
         // Collect results by entity.
diff --git a/core/modules/field/field.module b/core/modules/field/field.module
index 9d74dc9..68afafa 100644
--- a/core/modules/field/field.module
+++ b/core/modules/field/field.module
@@ -755,39 +755,6 @@ function field_view_mode_settings($entity_type, $bundle) {
 }
 
 /**
- * Returns the display settings to use for an instance in a given view mode.
- *
- * @param $instance
- *   The field instance being displayed.
- * @param $view_mode
- *   The view mode.
- * @param $entity
- *   The entity being displayed.
- *
- * @return
- *   The display settings to be used when displaying the field values.
- */
-function field_get_display($instance, $view_mode, $entity) {
-  // Check whether the view mode uses custom display settings or the 'default'
-  // mode.
-  $view_mode_settings = field_view_mode_settings($instance['entity_type'], $instance['bundle']);
-  $actual_mode = (!empty($view_mode_settings[$view_mode]['custom_settings']) ? $view_mode : 'default');
-  $display = $instance['display'][$actual_mode];
-
-  // Let modules alter the display settings.
-  $context = array(
-    'entity_type' => $instance['entity_type'],
-    'field' => field_info_field($instance['field_name']),
-    'instance' => $instance,
-    'entity' => $entity,
-    'view_mode' => $view_mode,
-  );
-  drupal_alter(array('field_display', 'field_display_' . $instance['entity_type']), $display, $context);
-
-  return $display;
-}
-
-/**
  * Returns the display settings to use for pseudo-fields in a given view mode.
  *
  * @param $entity_type
diff --git a/core/modules/field/lib/Drupal/field/Plugin/Type/Formatter/FormatterBase.php b/core/modules/field/lib/Drupal/field/Plugin/Type/Formatter/FormatterBase.php
index aceca43..5a23fa4 100644
--- a/core/modules/field/lib/Drupal/field/Plugin/Type/Formatter/FormatterBase.php
+++ b/core/modules/field/lib/Drupal/field/Plugin/Type/Formatter/FormatterBase.php
@@ -62,7 +62,7 @@ abstract class FormatterBase extends PluginSettingsBase implements FormatterInte
   /**
    * Constructs a FormatterBase object.
    *
-   * @param array $plugin_id
+   * @param string $plugin_id
    *   The plugin_id for the formatter.
    * @param Drupal\Component\Plugin\Discovery\DiscoveryInterface $discovery
    *   The Discovery class that holds access to the formatter implementation
diff --git a/core/modules/field/lib/Drupal/field/Plugin/Type/Formatter/FormatterInterface.php b/core/modules/field/lib/Drupal/field/Plugin/Type/Formatter/FormatterInterface.php
index 215e595..cf52530 100644
--- a/core/modules/field/lib/Drupal/field/Plugin/Type/Formatter/FormatterInterface.php
+++ b/core/modules/field/lib/Drupal/field/Plugin/Type/Formatter/FormatterInterface.php
@@ -34,7 +34,7 @@ interface FormatterInterface extends PluginSettingsInterface {
   public function settingsForm(array $form, array &$form_state);
 
   /**
-   * Return a short summary for the current formatter settings.
+   * Returns a short summary for the current formatter settings.
    *
    * If an empty result is returned, the formatter is assumed to have no
    * configurable settings, and no UI will be provided to display a settings
@@ -46,7 +46,7 @@ interface FormatterInterface extends PluginSettingsInterface {
   public function settingsSummary();
 
   /**
-   * Allow formatters to load information for field values being displayed.
+   * Allows formatters to load information for field values being displayed.
    *
    * This should be used when a formatter needs to load additional information
    * from the database in order to render a field, for example a reference