diff --git a/core/lib/Drupal/Core/Entity/EntityManager.php b/core/lib/Drupal/Core/Entity/EntityManager.php
index 1bdebcb..0a524b0 100644
--- a/core/lib/Drupal/Core/Entity/EntityManager.php
+++ b/core/lib/Drupal/Core/Entity/EntityManager.php
@@ -328,29 +328,26 @@ protected function buildBaseFieldDefinitions($entity_type_id) {
     $entity_type = $this->getDefinition($entity_type_id);
     $class = $entity_type->getClass();
 
-    $provider = $entity_type->getProvider();
+    // Retrieve base field definitions and assign them the entity type provider.
     $base_field_definitions = $class::baseFieldDefinitions($entity_type);
+    $provider = $entity_type->getProvider();
     foreach ($base_field_definitions as $definition) {
       $definition->setProvider($provider);
     }
 
     // Retrieve base field definitions from modules.
-    $base_field_module_definitions = array();
-    $hook = 'entity_base_field_info';
-    foreach ($this->moduleHandler->getImplementations($hook) as $module) {
-      $module_definitions = call_user_func($module . '_' . $hook, $entity_type);
-      if (isset($module_definitions) && is_array($module_definitions)) {
-        // Ensure the module key actually matches the name of the module defining
-        // the field.
+    foreach ($this->moduleHandler->getImplementations('entity_base_field_info') as $module) {
+      $module_definitions = $this->moduleHandler->invoke($module, 'entity_base_field_info', $entity_type);
+      if (!empty($module_definitions)) {
+        // Ensure the provider key actually matches the name of the provider
+        // defining the field.
         foreach ($module_definitions as $definition) {
           $definition->setProvider($provider);
         }
-        $return = NestedArray::mergeDeep($base_field_module_definitions, $module_definitions);
+        $base_field_definitions = NestedArray::mergeDeep($base_field_definitions, $module_definitions);
       }
     }
 
-    $base_field_definitions = NestedArray::mergeDeep($base_field_definitions, $base_field_module_definitions);
-
     // Automatically set the field name for non-configurable fields.
     foreach ($base_field_definitions as $field_name => $base_field_definition) {
       if ($base_field_definition instanceof FieldDefinition) {
@@ -360,7 +357,7 @@ protected function buildBaseFieldDefinitions($entity_type_id) {
     }
 
     // Invoke alter hook.
-    $this->moduleHandler->alter($hook, $base_field_definitions, $entity_type);
+    $this->moduleHandler->alter('entity_base_field_info', $base_field_definitions, $entity_type);
 
     // Ensure all basic fields are not defined as translatable.
     $keys = array_intersect_key(array_filter($entity_type->getKeys()), array_flip(array('id', 'revision', 'uuid', 'bundle')));
@@ -426,23 +423,18 @@ protected function buildBundleFieldDefinitions($entity_type_id, $bundle, array $
     }
 
     // Retrieve base field definitions from modules.
-    $bundle_field_module_definitions = array();
-    $hook = 'entity_bundle_field_info';
-    foreach ($this->moduleHandler->getImplementations($hook) as $module) {
-      $module_definitions = call_user_func($module . '_' . $hook, $entity_type, $bundle, $bundle_field_module_definitions);
-      if (isset($module_definitions) && is_array($module_definitions)) {
-        // Ensure the module key actually matches the name of the module defining
-        // the field.
+    foreach ($this->moduleHandler->getImplementations('entity_bundle_field_info') as $module) {
+      $module_definitions = $this->moduleHandler->invoke($module, 'entity_bundle_field_info', $entity_type, $bundle, $bundle_field_module_definitions);
+      if (!empty($module_definitions)) {
+        // Ensure the provider key actually matches the name of the provider
+        // defining the field.
         foreach ($module_definitions as $definition) {
           $definition->setProvider($provider);
         }
-        $return = NestedArray::mergeDeep($bundle_field_module_definitions, $module_definitions);
+        $bundle_field_definitions = NestedArray::mergeDeep($bundle_field_definitions, $module_definitions);
       }
     }
 
-    // Invoke 'per bundle' hook.
-    $bundle_field_definitions = NestedArray::mergeDeep($bundle_field_definitions, $bundle_field_module_definitions);
-
     // Automatically set the field name for non-configurable fields.
     foreach ($bundle_field_definitions as $field_name => $field_definition) {
       if ($field_definition instanceof FieldDefinition) {
diff --git a/core/lib/Drupal/Core/Field/FieldDefinition.php b/core/lib/Drupal/Core/Field/FieldDefinition.php
index c0732ad..e9c7f60 100644
--- a/core/lib/Drupal/Core/Field/FieldDefinition.php
+++ b/core/lib/Drupal/Core/Field/FieldDefinition.php
@@ -161,7 +161,7 @@ public function getProvider() {
    * @param string $provider
    *   The provider name.
    *
-   * @return static
+   * @return $this
    *   The object itself for chaining.
    */
   public function setProvider($provider) {
@@ -477,7 +477,7 @@ public static function getReservedColumns() {
   /**
    * {@inheritdoc}
    */
-  public function isCustomStorage() {
+  public function hasCustomStorage() {
     return !empty($this->definition['custom_storage']);
   }
 
@@ -488,7 +488,7 @@ public function isCustomStorage() {
    *   Pass TRUE if the field module will take care of storing field values,
    *   FALSE otherwise.
    *
-   * @return static
+   * @return $this
    *   The object itself for chaining.
    */
   public function setCustomStorage($custom_storage) {
diff --git a/core/lib/Drupal/Core/Field/FieldDefinitionInterface.php b/core/lib/Drupal/Core/Field/FieldDefinitionInterface.php
index cfc497b..f18071f 100644
--- a/core/lib/Drupal/Core/Field/FieldDefinitionInterface.php
+++ b/core/lib/Drupal/Core/Field/FieldDefinitionInterface.php
@@ -347,13 +347,14 @@ public function getColumns();
   /**
    * Returns the storage behavior for this field.
    *
-   * This indicates whether the storage controller should take care of storing
-   * the field values or whether the field module will do it.
+   * Indicates whether the entity type's storage controller should take care of
+   * storing the field values or whether the module providing the field will do
+   * that.
    *
    * @return bool
    *   TRUE if the field module takes care of storing field values, FALSE
    *   otherwise.
    */
-  public function isCustomStorage();
+  public function hasCustomStorage();
 
 }
diff --git a/core/modules/field/lib/Drupal/field/Entity/FieldConfig.php b/core/modules/field/lib/Drupal/field/Entity/FieldConfig.php
index 1b8b5bc..fd6eda1 100644
--- a/core/modules/field/lib/Drupal/field/Entity/FieldConfig.php
+++ b/core/modules/field/lib/Drupal/field/Entity/FieldConfig.php
@@ -478,7 +478,7 @@ public function getSchema() {
   /**
    * {@inheritdoc}
    */
-  public function isCustomStorage() {
+  public function hasCustomStorage() {
     return FALSE;
   }
 
@@ -593,11 +593,12 @@ public function getProvider() {
    * @param string $provider
    *   The provider name.
    *
-   * @return static
+   * @return $this
    *   The object itself for chaining.
    */
   public function setProvider($provider) {
-    // Do nothing: provider is readonly property.
+    // Do nothing: provider is a readonly property here.
+    return $this;
   }
 
   /**
diff --git a/core/modules/field/lib/Drupal/field/Entity/FieldInstanceConfig.php b/core/modules/field/lib/Drupal/field/Entity/FieldInstanceConfig.php
index 65f6c76..f3b361d 100644
--- a/core/modules/field/lib/Drupal/field/Entity/FieldInstanceConfig.php
+++ b/core/modules/field/lib/Drupal/field/Entity/FieldInstanceConfig.php
@@ -511,7 +511,7 @@ public function getProvider() {
    * @param string $provider
    *   The provider name.
    *
-   * @return static
+   * @return $this
    *   The object itself for chaining.
    */
   public function setProvider($provider) {
@@ -788,8 +788,8 @@ public function getColumns() {
   /**
    * {@inheritdoc}
    */
-  public function isCustomStorage() {
-    return $this->field->isCustomStorage();
+  public function hasCustomStorage() {
+    return $this->field->hasCustomStorage();
   }
 
 }