diff --git a/core/lib/Drupal/Core/Entity/ContentEntityConfirmFormBase.php b/core/lib/Drupal/Core/Entity/ContentEntityConfirmFormBase.php
index a174e31..635e446 100644
--- a/core/lib/Drupal/Core/Entity/ContentEntityConfirmFormBase.php
+++ b/core/lib/Drupal/Core/Entity/ContentEntityConfirmFormBase.php
@@ -81,14 +81,33 @@ public function form(array $form, array &$form_state) {
    * {@inheritdoc}
    */
   protected function actions(array $form, array &$form_state) {
-    $actions = parent::actions($form, $form_state);
-    $actions['submit']['#value'] = $this->getConfirmText();
-    unset($actions['delete']);
-
-    // Prepare cancel link.
-    $actions['cancel'] = ConfirmFormHelper::buildCancelLink($this, $this->getRequest());
-
-    return $actions;
+    return array(
+      'submit' => array(
+        '#value' => $this->getConfirmText(),
+        '#validate' => array(
+          array($this, 'validate'),
+        ),
+        '#submit' => array(
+          array($this, 'submitForm'),
+        ),
+      ),
+      'cancel' => ConfirmFormHelper::buildCancelLink($this, $this->getRequest()),
+    );
   }
 
+  /**
+   * {@inheritdoc}
+   *
+   * The save method makes no sense on EntityConfirmFormBase. Form submissions
+   * should be processed by overriding the submitForm method.
+   */
+  public function save(array $form, array &$form_state) {}
+
+  /**
+   * {@inheritdoc}
+   *
+   * The delete method makes no sense on EntityConfirmFormBase. Form submissions
+   * should be processed by overriding the submitForm method.
+   */
+  public function delete(array $form, array &$form_state) {}
 }
diff --git a/core/lib/Drupal/Core/Entity/EntityConfirmFormBase.php b/core/lib/Drupal/Core/Entity/EntityConfirmFormBase.php
index 564fa88..1cb1083 100644
--- a/core/lib/Drupal/Core/Entity/EntityConfirmFormBase.php
+++ b/core/lib/Drupal/Core/Entity/EntityConfirmFormBase.php
@@ -74,13 +74,34 @@ public function buildForm(array $form, array &$form_state) {
    * {@inheritdoc}
    */
   protected function actions(array $form, array &$form_state) {
-    $actions = parent::actions($form, $form_state);
-    $actions['submit']['#value'] = $this->getConfirmText();
-    unset($actions['delete']);
-
-    // Prepare cancel link.
-    $actions['cancel'] = ConfirmFormHelper::buildCancelLink($this, $this->getRequest());
-    return $actions;
+    return array(
+      'submit' => array(
+        '#value' => $this->getConfirmText(),
+        '#validate' => array(
+          array($this, 'validate'),
+        ),
+        '#submit' => array(
+          array($this, 'submitForm'),
+        ),
+      ),
+      'cancel' => ConfirmFormHelper::buildCancelLink($this, $this->getRequest()),
+    );
   }
 
+  /**
+   * {@inheritdoc}
+   *
+   * The save method makes no sense on EntityConfirmFormBase. Form submissions
+   * should be processed by overriding the submitForm method.
+   */
+  public function save(array $form, array &$form_state) {}
+
+  /**
+   * {@inheritdoc}
+   *
+   * The delete method makes no sense on EntityConfirmFormBase. Form submissions
+   * should be processed by overriding the submitForm method.
+   */
+  public function delete(array $form, array &$form_state) {}
+
 }
diff --git a/core/lib/Drupal/Core/Entity/EntityForm.php b/core/lib/Drupal/Core/Entity/EntityForm.php
index c80daa4..80f4200 100644
--- a/core/lib/Drupal/Core/Entity/EntityForm.php
+++ b/core/lib/Drupal/Core/Entity/EntityForm.php
@@ -105,12 +105,6 @@ public function buildForm(array $form, array &$form_state) {
   }
 
   /**
-   * {@inheritdoc}
-   */
-  public function submitForm(array &$form, array &$form_state) {
-  }
-
-  /**
    * Initialize the form state and the entity before the first form build.
    */
   protected function init(array &$form_state) {
@@ -207,7 +201,9 @@ protected function actionsElement(array $form, array &$form_state) {
    *   many entity types.
    */
   protected function actions(array $form, array &$form_state) {
-    // @todo Rename the action key from submit to save.
+    // @todo Consider renaming the action key from submit to save. The impacts
+      //   are hard to predict. For example, see
+      //   language_configuration_element_process().
     $actions['submit'] = array(
       '#type' => 'submit',
       '#value' => $this->t('Save'),
@@ -215,7 +211,7 @@ protected function actions(array $form, array &$form_state) {
         array($this, 'validate'),
       ),
       '#submit' => array(
-        array($this, 'submit'),
+        array($this, 'submitForm'),
         array($this, 'save'),
       ),
     );
@@ -255,33 +251,38 @@ public function validate(array $form, array &$form_state) {
    * {@inheritdoc}
    *
    * This is the default entity object builder function. It is called before any
-   * other submit handler to build the new entity object to be passed to the
+   * other submit handler to build the new entity object to be used by the
    * following submit handlers. At this point of the form workflow the entity is
    * validated and the form state can be updated, this way the subsequently
-   * invoked handlers can retrieve a regular entity object to act on.
+   * invoked handlers can retrieve a regular entity object to act on. Generally
+   * this method should not be overridden unless the entity requires the same
+   * preparation for two actions, see \Drupal\comment\CommentFormController for
+   * an example with the save and preview actions.
    *
    * @param array $form
    *   An associative array containing the structure of the form.
    * @param array $form_state
    *   A reference to a keyed array containing the current state of the form.
    */
-  public function submit(array $form, array &$form_state) {
+  public function submitForm(array &$form, array &$form_state) {
     // Remove button and internal Form API values from submitted values.
     form_state_values_clean($form_state);
     $this->entity = $this->buildEntity($form, $form_state);
-    return $this->entity;
   }
 
   /**
    * Form submission handler for the 'save' action.
    *
+   * Normally this method should be overridden to provide specific messages to
+   * the user and redirect the form after the entity has been saved.
+   *
    * @param array $form
    *   An associative array containing the structure of the form.
    * @param array $form_state
    *   A reference to a keyed array containing the current state of the form.
    */
   public function save(array $form, array &$form_state) {
-    // @todo Perform common save operations.
+    $this->entity->save();
   }
 
   /**
diff --git a/core/lib/Drupal/Core/Entity/EntityFormInterface.php b/core/lib/Drupal/Core/Entity/EntityFormInterface.php
index aae4c5f..df1566d 100644
--- a/core/lib/Drupal/Core/Entity/EntityFormInterface.php
+++ b/core/lib/Drupal/Core/Entity/EntityFormInterface.php
@@ -115,20 +115,6 @@ public function buildEntity(array $form, array &$form_state);
   public function validate(array $form, array &$form_state);
 
   /**
-   * Updates the form's entity by processing this submission's values.
-   *
-   * Note: Before this can be safely invoked the entity form must have passed
-   * validation, i.e. only add this as form #submit handler if validation is
-   * added as well.
-   *
-   * @param array $form
-   *   A nested array form elements comprising the form.
-   * @param array $form_state
-   *   An associative array containing the current state of the form.
-   */
-  public function submit(array $form, array &$form_state);
-
-  /**
    * Sets the translation manager for this form.
    *
    * @param \Drupal\Core\StringTranslation\TranslationInterface $translation_manager
diff --git a/core/modules/action/lib/Drupal/action/ActionFormBase.php b/core/modules/action/lib/Drupal/action/ActionFormBase.php
index c2cbee3..64a52bd 100644
--- a/core/modules/action/lib/Drupal/action/ActionFormBase.php
+++ b/core/modules/action/lib/Drupal/action/ActionFormBase.php
@@ -133,13 +133,12 @@ public function validate(array $form, array &$form_state) {
   /**
    * {@inheritdoc}
    */
-  public function submit(array $form, array &$form_state) {
-    parent::submit($form, $form_state);
+  public function submitForm(array &$form, array &$form_state) {
+    parent::submitForm($form, $form_state);
 
     if ($this->plugin instanceof PluginFormInterface) {
       $this->plugin->submitConfigurationForm($form, $form_state);
     }
-    return $this->entity;
   }
 
   /**
diff --git a/core/modules/action/lib/Drupal/action/Form/ActionDeleteForm.php b/core/modules/action/lib/Drupal/action/Form/ActionDeleteForm.php
index 968b7f0..02cbfb2 100644
--- a/core/modules/action/lib/Drupal/action/Form/ActionDeleteForm.php
+++ b/core/modules/action/lib/Drupal/action/Form/ActionDeleteForm.php
@@ -40,7 +40,7 @@ public function getCancelRoute() {
   /**
    * {@inheritdoc}
    */
-  public function submit(array $form, array &$form_state) {
+  public function submitForm(array &$form, array &$form_state) {
     $this->entity->delete();
 
     watchdog('user', 'Deleted action %aid (%action)', array('%aid' => $this->entity->id(), '%action' => $this->entity->label()));
diff --git a/core/modules/aggregator/lib/Drupal/aggregator/Form/FeedDeleteForm.php b/core/modules/aggregator/lib/Drupal/aggregator/Form/FeedDeleteForm.php
index 7cc3827..8c3a817 100644
--- a/core/modules/aggregator/lib/Drupal/aggregator/Form/FeedDeleteForm.php
+++ b/core/modules/aggregator/lib/Drupal/aggregator/Form/FeedDeleteForm.php
@@ -40,7 +40,7 @@ public function getConfirmText() {
   /**
    * {@inheritdoc}
    */
-  public function submit(array $form, array &$form_state) {
+  public function submitForm(array &$form, array &$form_state) {
     $this->entity->delete();
     watchdog('aggregator', 'Feed %feed deleted.', array('%feed' => $this->entity->label()));
     drupal_set_message($this->t('The feed %feed has been deleted.', array('%feed' => $this->entity->label())));
diff --git a/core/modules/aggregator/lib/Drupal/aggregator/Form/FeedItemsDeleteForm.php b/core/modules/aggregator/lib/Drupal/aggregator/Form/FeedItemsDeleteForm.php
index f053281..6fcf914 100644
--- a/core/modules/aggregator/lib/Drupal/aggregator/Form/FeedItemsDeleteForm.php
+++ b/core/modules/aggregator/lib/Drupal/aggregator/Form/FeedItemsDeleteForm.php
@@ -40,7 +40,7 @@ public function getConfirmText() {
   /**
    * {@inheritdoc}
    */
-  public function submit(array $form, array &$form_state) {
+  public function submitForm(array &$form, array &$form_state) {
     $this->entity->deleteItems();
 
     $form_state['redirect_route']['route_name'] = 'aggregator.admin_overview';
diff --git a/core/modules/block/custom_block/lib/Drupal/custom_block/CustomBlockForm.php b/core/modules/block/custom_block/lib/Drupal/custom_block/CustomBlockForm.php
index f495c4f..7aacbff 100644
--- a/core/modules/block/custom_block/lib/Drupal/custom_block/CustomBlockForm.php
+++ b/core/modules/block/custom_block/lib/Drupal/custom_block/CustomBlockForm.php
@@ -167,7 +167,7 @@ public function form(array $form, array &$form_state) {
   }
 
   /**
-   * Overrides \Drupal\Core\Entity\EntityForm::submit().
+   * {@inheritdoc}
    *
    * Updates the custom block object by processing the submitted values.
    *
@@ -175,23 +175,15 @@ public function form(array $form, array &$form_state) {
    * form state's entity with the current step's values before proceeding to the
    * next step.
    */
-  public function submit(array $form, array &$form_state) {
-    // Build the block object from the submitted values.
-    $block = parent::submit($form, $form_state);
+  public function save(array $form, array &$form_state) {
+    /** @var \Drupal\custom_block\CustomBlockInterface $block */
+    $block = $this->entity;
 
     // Save as a new revision if requested to do so.
     if (!empty($form_state['values']['revision'])) {
       $block->setNewRevision();
     }
 
-    return $block;
-  }
-
-  /**
-   * {@inheritdoc}
-   */
-  public function save(array $form, array &$form_state) {
-    $block = $this->entity;
     $insert = $block->isNew();
     $block->save();
     $watchdog_args = array('@type' => $block->bundle(), '%info' => $block->label());
diff --git a/core/modules/block/custom_block/lib/Drupal/custom_block/CustomBlockTypeForm.php b/core/modules/block/custom_block/lib/Drupal/custom_block/CustomBlockTypeForm.php
index c790efa..75b133f 100644
--- a/core/modules/block/custom_block/lib/Drupal/custom_block/CustomBlockTypeForm.php
+++ b/core/modules/block/custom_block/lib/Drupal/custom_block/CustomBlockTypeForm.php
@@ -85,7 +85,7 @@ public function form(array $form, array &$form_state) {
   }
 
   /**
-   * Overrides \Drupal\Core\Entity\EntityForm::save().
+   * {@inheritdoc}
    */
   public function save(array $form, array &$form_state) {
     $block_type = $this->entity;
diff --git a/core/modules/block/custom_block/lib/Drupal/custom_block/Form/CustomBlockDeleteForm.php b/core/modules/block/custom_block/lib/Drupal/custom_block/Form/CustomBlockDeleteForm.php
index 36df166..4d17f11 100644
--- a/core/modules/block/custom_block/lib/Drupal/custom_block/Form/CustomBlockDeleteForm.php
+++ b/core/modules/block/custom_block/lib/Drupal/custom_block/Form/CustomBlockDeleteForm.php
@@ -54,7 +54,7 @@ public function buildForm(array $form, array &$form_state) {
   /**
    * {@inheritdoc}
    */
-  public function submit(array $form, array &$form_state) {
+  public function submitForm(array &$form, array &$form_state) {
     $this->entity->delete();
     drupal_set_message($this->t('Custom block %label has been deleted.', array('%label' => $this->entity->label())));
     watchdog('custom_block', 'Custom block %label has been deleted.', array('%label' => $this->entity->label()), WATCHDOG_NOTICE);
diff --git a/core/modules/block/custom_block/lib/Drupal/custom_block/Form/CustomBlockTypeDeleteForm.php b/core/modules/block/custom_block/lib/Drupal/custom_block/Form/CustomBlockTypeDeleteForm.php
index 8b7a681..25e5268 100644
--- a/core/modules/block/custom_block/lib/Drupal/custom_block/Form/CustomBlockTypeDeleteForm.php
+++ b/core/modules/block/custom_block/lib/Drupal/custom_block/Form/CustomBlockTypeDeleteForm.php
@@ -83,7 +83,7 @@ public function buildForm(array $form, array &$form_state) {
   /**
    * {@inheritdoc}
    */
-  public function submit(array $form, array &$form_state) {
+  public function submitForm(array &$form, array &$form_state) {
     $this->entity->delete();
     $form_state['redirect_route']['route_name'] = 'custom_block.type_list';
     drupal_set_message(t('Custom block type %label has been deleted.', array('%label' => $this->entity->label())));
diff --git a/core/modules/block/lib/Drupal/block/BlockForm.php b/core/modules/block/lib/Drupal/block/BlockForm.php
index 350fde6..005a63e 100644
--- a/core/modules/block/lib/Drupal/block/BlockForm.php
+++ b/core/modules/block/lib/Drupal/block/BlockForm.php
@@ -302,8 +302,8 @@ public function validate(array $form, array &$form_state) {
   /**
    * {@inheritdoc}
    */
-  public function submit(array $form, array &$form_state) {
-    parent::submit($form, $form_state);
+  public function submitForm(array &$form, array &$form_state) {
+    parent::submitForm($form, $form_state);
 
     $entity = $this->entity;
     // The Block Entity form puts all block plugin form elements in the
diff --git a/core/modules/block/lib/Drupal/block/Form/BlockDeleteForm.php b/core/modules/block/lib/Drupal/block/Form/BlockDeleteForm.php
index 20c1e7e..90bb8ac 100644
--- a/core/modules/block/lib/Drupal/block/Form/BlockDeleteForm.php
+++ b/core/modules/block/lib/Drupal/block/Form/BlockDeleteForm.php
@@ -40,7 +40,7 @@ public function getConfirmText() {
   /**
    * {@inheritdoc}
    */
-  public function submit(array $form, array &$form_state) {
+  public function submitForm(array &$form, array &$form_state) {
     $this->entity->delete();
     drupal_set_message($this->t('The block %name has been removed.', array('%name' => $this->entity->label())));
     $form_state['redirect_route']['route_name'] = 'block.admin_display';
diff --git a/core/modules/book/lib/Drupal/book/Form/BookOutlineForm.php b/core/modules/book/lib/Drupal/book/Form/BookOutlineForm.php
index f4a97a1..3d146c2 100644
--- a/core/modules/book/lib/Drupal/book/Form/BookOutlineForm.php
+++ b/core/modules/book/lib/Drupal/book/Form/BookOutlineForm.php
@@ -97,10 +97,8 @@ protected function actions(array $form, array &$form_state) {
 
   /**
    * {@inheritdoc}
-   *
-   * @see book_remove_button_submit()
    */
-  public function submit(array $form, array &$form_state) {
+  public function save(array $form, array &$form_state) {
     $form_state['redirect_route'] = array(
       'route_name' => 'node.view',
       'route_parameters' => array(
diff --git a/core/modules/comment/lib/Drupal/comment/CommentForm.php b/core/modules/comment/lib/Drupal/comment/CommentForm.php
index ad0de74..f4c8df3 100644
--- a/core/modules/comment/lib/Drupal/comment/CommentForm.php
+++ b/core/modules/comment/lib/Drupal/comment/CommentForm.php
@@ -262,7 +262,7 @@ protected function actions(array $form, array &$form_state) {
         array($this, 'validate'),
       ),
       '#submit' => array(
-        array($this, 'submit'),
+        array($this, 'submitForm'),
         array($this, 'preview'),
       ),
     );
@@ -319,12 +319,12 @@ public function buildEntity(array $form, array &$form_state) {
   }
 
   /**
-   * Overrides Drupal\Core\Entity\EntityForm::submit().
+   * {@inheritdoc}
    */
-  public function submit(array $form, array &$form_state) {
+  public function submitForm(array &$form, array &$form_state) {
+    parent::submitForm($form, $form_state);
     /** @var \Drupal\comment\CommentInterface $comment */
-    $comment = parent::submit($form, $form_state);
-
+    $comment = $this->entity;
     // If the comment was posted by a registered user, assign the author's ID.
     // @todo Too fragile. Should be prepared and stored in comment_form()
     // already.
diff --git a/core/modules/comment/lib/Drupal/comment/Form/DeleteForm.php b/core/modules/comment/lib/Drupal/comment/Form/DeleteForm.php
index b2687f1..86d52e2 100644
--- a/core/modules/comment/lib/Drupal/comment/Form/DeleteForm.php
+++ b/core/modules/comment/lib/Drupal/comment/Form/DeleteForm.php
@@ -90,7 +90,7 @@ public function getConfirmText() {
   /**
    * {@inheritdoc}
    */
-  public function submit(array $form, array &$form_state) {
+  public function submitForm(array &$form, array &$form_state) {
     // Delete the comment and its replies.
     $this->entity->delete();
     drupal_set_message($this->t('The comment and all its replies have been deleted.'));
diff --git a/core/modules/config/tests/config_test/lib/Drupal/config_test/ConfigTestForm.php b/core/modules/config/tests/config_test/lib/Drupal/config_test/ConfigTestForm.php
index 6fcc00c..7cee08c 100644
--- a/core/modules/config/tests/config_test/lib/Drupal/config_test/ConfigTestForm.php
+++ b/core/modules/config/tests/config_test/lib/Drupal/config_test/ConfigTestForm.php
@@ -66,7 +66,7 @@ public function form(array $form, array &$form_state) {
   }
 
   /**
-   * Overrides Drupal\Core\Entity\EntityForm::save().
+   * {@inheritdoc}
    */
   public function save(array $form, array &$form_state) {
     $entity = $this->entity;
diff --git a/core/modules/config/tests/config_test/lib/Drupal/config_test/Form/ConfigTestDeleteForm.php b/core/modules/config/tests/config_test/lib/Drupal/config_test/Form/ConfigTestDeleteForm.php
index 4d0a184..fe8fa67 100644
--- a/core/modules/config/tests/config_test/lib/Drupal/config_test/Form/ConfigTestDeleteForm.php
+++ b/core/modules/config/tests/config_test/lib/Drupal/config_test/Form/ConfigTestDeleteForm.php
@@ -40,7 +40,7 @@ public function getCancelRoute() {
   /**
    * {@inheritdoc}
    */
-  public function submit(array $form, array &$form_state) {
+  public function submitForm(array &$form, array &$form_state) {
     $this->entity->delete();
     drupal_set_message(String::format('%label configuration has been deleted.', array('%label' => $this->entity->label())));
     $form_state['redirect_route']['route_name'] = 'config_test.list_page';
diff --git a/core/modules/contact/lib/Drupal/contact/CategoryForm.php b/core/modules/contact/lib/Drupal/contact/CategoryForm.php
index a810b1e..33d9bbc 100644
--- a/core/modules/contact/lib/Drupal/contact/CategoryForm.php
+++ b/core/modules/contact/lib/Drupal/contact/CategoryForm.php
@@ -93,7 +93,7 @@ public function validate(array $form, array &$form_state) {
   }
 
   /**
-   * Overrides Drupal\Core\Entity\EntityForm::save().
+   * {@inheritdoc}
    */
   public function save(array $form, array &$form_state) {
     $category = $this->entity;
diff --git a/core/modules/contact/lib/Drupal/contact/Form/CategoryDeleteForm.php b/core/modules/contact/lib/Drupal/contact/Form/CategoryDeleteForm.php
index dac498e..4e5b089 100644
--- a/core/modules/contact/lib/Drupal/contact/Form/CategoryDeleteForm.php
+++ b/core/modules/contact/lib/Drupal/contact/Form/CategoryDeleteForm.php
@@ -40,7 +40,7 @@ public function getConfirmText() {
   /**
    * {@inheritdoc}
    */
-  public function submit(array $form, array &$form_state) {
+  public function submitForm(array &$form, array &$form_state) {
     $this->entity->delete();
     drupal_set_message(t('Category %label has been deleted.', array('%label' => $this->entity->label())));
     watchdog('contact', 'Category %label has been deleted.', array('%label' => $this->entity->label()), WATCHDOG_NOTICE);
diff --git a/core/modules/contact/lib/Drupal/contact/MessageForm.php b/core/modules/contact/lib/Drupal/contact/MessageForm.php
index d28a8cb..4dc8e16 100644
--- a/core/modules/contact/lib/Drupal/contact/MessageForm.php
+++ b/core/modules/contact/lib/Drupal/contact/MessageForm.php
@@ -165,7 +165,7 @@ public function actions(array $form, array &$form_state) {
         array($this, 'validate'),
       ),
       '#submit' => array(
-        array($this, 'submit'),
+        array($this, 'submitForm'),
         array($this, 'preview'),
       ),
     );
@@ -182,7 +182,7 @@ public function preview(array $form, array &$form_state) {
   }
 
   /**
-   * Overrides Drupal\Core\Entity\EntityForm::save().
+   * {@inheritdoc}
    */
   public function save(array $form, array &$form_state) {
     $user = \Drupal::currentUser();
diff --git a/core/modules/entity/lib/Drupal/entity/Form/EntityDisplayModeDeleteForm.php b/core/modules/entity/lib/Drupal/entity/Form/EntityDisplayModeDeleteForm.php
index d2f22d0..4ea5ff3 100644
--- a/core/modules/entity/lib/Drupal/entity/Form/EntityDisplayModeDeleteForm.php
+++ b/core/modules/entity/lib/Drupal/entity/Form/EntityDisplayModeDeleteForm.php
@@ -49,11 +49,9 @@ public function getConfirmText() {
   /**
    * {@inheritdoc}
    */
-  public function submit(array $form, array &$form_state) {
-    parent::submit($form, $form_state);
-
+  public function submitForm(array &$form, array &$form_state) {
     $entity_type = $this->entity->getEntityType();
-    drupal_set_message(t('Deleted the %label @entity-type.', array('%label' => $this->entity->label(), '@entity-type' => $entity_type->getLowercaseLabel())));
+    drupal_set_message(t('Deleted the %label @entity-type.', array('%label' => $this->entity->label(), '@entity-type' => strtolower($entity_type->getLabel()))));
     $this->entity->delete();
     entity_info_cache_clear();
     $form_state['redirect_route']['route_name'] = 'entity.' . $this->entity->getEntityTypeId() . '_list';
diff --git a/core/modules/field_ui/lib/Drupal/field_ui/Form/FieldInstanceConfigDeleteForm.php b/core/modules/field_ui/lib/Drupal/field_ui/Form/FieldInstanceConfigDeleteForm.php
index 87dfafc..f1357ff 100644
--- a/core/modules/field_ui/lib/Drupal/field_ui/Form/FieldInstanceConfigDeleteForm.php
+++ b/core/modules/field_ui/lib/Drupal/field_ui/Form/FieldInstanceConfigDeleteForm.php
@@ -67,7 +67,7 @@ public function getCancelRoute() {
   /**
    * {@inheritdoc}
    */
-  public function submit(array $form, array &$form_state) {
+  public function submitForm(array &$form, array &$form_state) {
     $field = $this->entity->getField();
     $bundles = entity_get_bundles();
     $bundle_label = $bundles[$this->entity->entity_type][$this->entity->bundle]['label'];
diff --git a/core/modules/filter/lib/Drupal/filter/FilterFormatAddForm.php b/core/modules/filter/lib/Drupal/filter/FilterFormatAddForm.php
index b8814f4..05a80be 100644
--- a/core/modules/filter/lib/Drupal/filter/FilterFormatAddForm.php
+++ b/core/modules/filter/lib/Drupal/filter/FilterFormatAddForm.php
@@ -22,10 +22,9 @@ public function form(array $form, array &$form_state) {
   /**
    * {@inheritdoc}
    */
-  public function submit(array $form, array &$form_state) {
-    parent::submit($form, $form_state);
+  public function submitForm(array &$form, array &$form_state) {
+    parent::submitForm($form, $form_state);
     drupal_set_message(t('Added text format %format.', array('%format' => $this->entity->label())));
-    return $this->entity;
   }
 
 }
diff --git a/core/modules/filter/lib/Drupal/filter/FilterFormatEditForm.php b/core/modules/filter/lib/Drupal/filter/FilterFormatEditForm.php
index 42cdc64..8090dea 100644
--- a/core/modules/filter/lib/Drupal/filter/FilterFormatEditForm.php
+++ b/core/modules/filter/lib/Drupal/filter/FilterFormatEditForm.php
@@ -31,10 +31,9 @@ public function form(array $form, array &$form_state) {
   /**
    * {@inheritdoc}
    */
-  public function submit(array $form, array &$form_state) {
-    parent::submit($form, $form_state);
+  public function submitForm(array &$form, array &$form_state) {
+    parent::submitForm($form, $form_state);
     drupal_set_message(t('The text format %format has been updated.', array('%format' => $this->entity->label())));
-    return $this->entity;
   }
 
 }
diff --git a/core/modules/filter/lib/Drupal/filter/FilterFormatFormBase.php b/core/modules/filter/lib/Drupal/filter/FilterFormatFormBase.php
index 2f986ff..608b94f 100644
--- a/core/modules/filter/lib/Drupal/filter/FilterFormatFormBase.php
+++ b/core/modules/filter/lib/Drupal/filter/FilterFormatFormBase.php
@@ -244,8 +244,8 @@ public function validate(array $form, array &$form_state) {
   /**
    * {@inheritdoc}
    */
-  public function submit(array $form, array &$form_state) {
-    parent::submit($form, $form_state);
+  public function submitForm(array &$form, array &$form_state) {
+    parent::submitForm($form, $form_state);
 
     // Add the submitted form values to the text format, and save it.
     $format = $this->entity;
diff --git a/core/modules/filter/lib/Drupal/filter/Form/FilterDisableForm.php b/core/modules/filter/lib/Drupal/filter/Form/FilterDisableForm.php
index 125015e..ddd6d7e 100644
--- a/core/modules/filter/lib/Drupal/filter/Form/FilterDisableForm.php
+++ b/core/modules/filter/lib/Drupal/filter/Form/FilterDisableForm.php
@@ -47,7 +47,7 @@ public function getDescription() {
   /**
    * {@inheritdoc}
    */
-  public function submit(array $form, array &$form_state) {
+  public function submitForm(array &$form, array &$form_state) {
     $this->entity->disable()->save();
     drupal_set_message(t('Disabled text format %format.', array('%format' => $this->entity->label())));
 
diff --git a/core/modules/image/lib/Drupal/image/Form/ImageStyleAddForm.php b/core/modules/image/lib/Drupal/image/Form/ImageStyleAddForm.php
index 64c2a37..6054e78 100644
--- a/core/modules/image/lib/Drupal/image/Form/ImageStyleAddForm.php
+++ b/core/modules/image/lib/Drupal/image/Form/ImageStyleAddForm.php
@@ -15,8 +15,8 @@ class ImageStyleAddForm extends ImageStyleFormBase {
   /**
    * {@inheritdoc}
    */
-  public function save(array $form, array &$form_state) {
-    parent::save($form, $form_state);
+  public function submitForm(array &$form, array &$form_state) {
+    parent::submitForm($form, $form_state);
     drupal_set_message($this->t('Style %name was created.', array('%name' => $this->entity->label())));
   }
 
diff --git a/core/modules/image/lib/Drupal/image/Form/ImageStyleDeleteForm.php b/core/modules/image/lib/Drupal/image/Form/ImageStyleDeleteForm.php
index 470f31d..a3e6db3 100644
--- a/core/modules/image/lib/Drupal/image/Form/ImageStyleDeleteForm.php
+++ b/core/modules/image/lib/Drupal/image/Form/ImageStyleDeleteForm.php
@@ -62,7 +62,7 @@ public function form(array $form, array &$form_state) {
   /**
    * {@inheritdoc}
    */
-  public function submit(array $form, array &$form_state) {
+  public function submitForm(array &$form, array &$form_state) {
     $this->entity->set('replacementID', $form_state['values']['replacement']);
     $this->entity->delete();
     drupal_set_message($this->t('Style %name was deleted.', array('%name' => $this->entity->label())));
diff --git a/core/modules/image/lib/Drupal/image/Form/ImageStyleEditForm.php b/core/modules/image/lib/Drupal/image/Form/ImageStyleEditForm.php
index 1e7d782..930b56c 100644
--- a/core/modules/image/lib/Drupal/image/Form/ImageStyleEditForm.php
+++ b/core/modules/image/lib/Drupal/image/Form/ImageStyleEditForm.php
@@ -213,14 +213,14 @@ public function effectSave($form, &$form_state) {
   /**
    * {@inheritdoc}
    */
-  public function save(array $form, array &$form_state) {
+  public function submitForm(array &$form, array &$form_state) {
 
     // Update image effect weights.
     if (!empty($form_state['values']['effects'])) {
       $this->updateEffectWeights($form_state['values']['effects']);
     }
 
-    parent::save($form, $form_state);
+    parent::submitForm($form, $form_state);
     drupal_set_message($this->t('Changes to the style have been saved.'));
   }
 
diff --git a/core/modules/image/lib/Drupal/image/Form/ImageStyleFlushForm.php b/core/modules/image/lib/Drupal/image/Form/ImageStyleFlushForm.php
index 2c87bb2..7f848fd 100644
--- a/core/modules/image/lib/Drupal/image/Form/ImageStyleFlushForm.php
+++ b/core/modules/image/lib/Drupal/image/Form/ImageStyleFlushForm.php
@@ -47,7 +47,7 @@ public function getCancelRoute() {
   /**
    * {@inheritdoc}
    */
-  public function submit(array $form, array &$form_state) {
+  public function submitForm(array &$form, array &$form_state) {
     $this->entity->flush();
     drupal_set_message($this->t('The image style %name has been flushed.', array('%name' => $this->entity->label())));
     $form_state['redirect_route']['route_name'] = 'image.style_list';
diff --git a/core/modules/language/lib/Drupal/language/Form/LanguageDeleteForm.php b/core/modules/language/lib/Drupal/language/Form/LanguageDeleteForm.php
index 241bbe7..b0dba10 100644
--- a/core/modules/language/lib/Drupal/language/Form/LanguageDeleteForm.php
+++ b/core/modules/language/lib/Drupal/language/Form/LanguageDeleteForm.php
@@ -106,7 +106,7 @@ public function buildForm(array $form, array &$form_state) {
   /**
    * {@inheritdoc}
    */
-  public function submit(array $form, array &$form_state) {
+  public function submitForm(array &$form, array &$form_state) {
     // @todo This should be replaced with $this->entity->delete() when the
     //   additional logic in language_delete() is ported.
     $success = language_delete($this->entity->id());
diff --git a/core/modules/menu_link/lib/Drupal/menu_link/MenuLinkForm.php b/core/modules/menu_link/lib/Drupal/menu_link/MenuLinkForm.php
index 422906f..4a20cd4 100644
--- a/core/modules/menu_link/lib/Drupal/menu_link/MenuLinkForm.php
+++ b/core/modules/menu_link/lib/Drupal/menu_link/MenuLinkForm.php
@@ -270,11 +270,12 @@ public function buildEntity(array $form, array &$form_state) {
   }
 
   /**
-   * Overrides EntityForm::submit().
+   * {@inheritdoc}
    */
-  public function submit(array $form, array &$form_state) {
+  public function submitForm(array &$form, array &$form_state) {
     // Build the menu link object from the submitted values.
-    $menu_link = parent::submit($form, $form_state);
+    parent::submitForm($form, $form_state);
+    $menu_link = $this->entity;
 
     // The value of "hidden" is the opposite of the value supplied by the
     // "enabled" checkbox.
@@ -283,8 +284,6 @@ public function submit(array $form, array &$form_state) {
 
     $menu_link->options['attributes']['title'] = $menu_link->description;
     list($menu_link->menu_name, $menu_link->plid) = explode(':', $menu_link->parent);
-
-    return $menu_link;
   }
 
   /**
diff --git a/core/modules/menu_ui/lib/Drupal/menu_ui/Form/MenuDeleteForm.php b/core/modules/menu_ui/lib/Drupal/menu_ui/Form/MenuDeleteForm.php
index 98a45db..980a821 100644
--- a/core/modules/menu_ui/lib/Drupal/menu_ui/Form/MenuDeleteForm.php
+++ b/core/modules/menu_ui/lib/Drupal/menu_ui/Form/MenuDeleteForm.php
@@ -96,7 +96,7 @@ public function getConfirmText() {
   /**
    * {@inheritdoc}
    */
-  public function submit(array $form, array &$form_state) {
+  public function submitForm(array &$form, array &$form_state) {
     $form_state['redirect_route']['route_name'] = 'menu_ui.overview_page';
 
     // Locked menus may not be deleted.
diff --git a/core/modules/menu_ui/lib/Drupal/menu_ui/Form/MenuLinkDeleteForm.php b/core/modules/menu_ui/lib/Drupal/menu_ui/Form/MenuLinkDeleteForm.php
index eeb40a6..8f5e9f6 100644
--- a/core/modules/menu_ui/lib/Drupal/menu_ui/Form/MenuLinkDeleteForm.php
+++ b/core/modules/menu_ui/lib/Drupal/menu_ui/Form/MenuLinkDeleteForm.php
@@ -36,7 +36,7 @@ public function getCancelRoute() {
   /**
    * {@inheritdoc}
    */
-  public function submit(array $form, array &$form_state) {
+  public function submitForm(array &$form, array &$form_state) {
     menu_link_delete($this->entity->id());
     $t_args = array('%title' => $this->entity->link_title);
     drupal_set_message(t('The menu link %title has been deleted.', $t_args));
diff --git a/core/modules/menu_ui/lib/Drupal/menu_ui/Form/MenuLinkResetForm.php b/core/modules/menu_ui/lib/Drupal/menu_ui/Form/MenuLinkResetForm.php
index 31b23ab..f44ffb3 100644
--- a/core/modules/menu_ui/lib/Drupal/menu_ui/Form/MenuLinkResetForm.php
+++ b/core/modules/menu_ui/lib/Drupal/menu_ui/Form/MenuLinkResetForm.php
@@ -50,7 +50,7 @@ public function getConfirmText() {
   /**
    * {@inheritdoc}
    */
-  public function submit(array $form, array &$form_state) {
+  public function submitForm(array &$form, array &$form_state) {
     $new_menu_link = $this->entity->reset();
     drupal_set_message(t('The menu link was reset to its default settings.'));
     $form_state['redirect_route'] = array(
diff --git a/core/modules/menu_ui/lib/Drupal/menu_ui/MenuForm.php b/core/modules/menu_ui/lib/Drupal/menu_ui/MenuForm.php
index aa8a51a..108c297 100644
--- a/core/modules/menu_ui/lib/Drupal/menu_ui/MenuForm.php
+++ b/core/modules/menu_ui/lib/Drupal/menu_ui/MenuForm.php
@@ -181,14 +181,14 @@ protected function actions(array $form, array &$form_state) {
     $actions['delete']['#access'] = !$this->entity->isNew() && $this->entity->access('delete');
 
     // Add the language configuration submit handler. This is needed because the
-    // submit button has custom submit handlers.
+    // save button has custom submit handlers.
     if ($this->moduleHandler->moduleExists('language')) {
       array_unshift($actions['submit']['#submit'],'language_configuration_element_submit');
       array_unshift($actions['submit']['#submit'], array($this, 'languageConfigurationSubmit'));
     }
     // We cannot leverage the regular submit handler definition because we have
     // button-specific ones here. Hence we need to explicitly set it for the
-    // submit action, otherwise it would be ignored.
+    // save action, otherwise it would be ignored.
     if ($this->moduleHandler->moduleExists('content_translation')) {
       array_unshift($actions['submit']['#submit'], 'content_translation_language_configuration_element_submit');
     }
diff --git a/core/modules/node/lib/Drupal/node/Form/NodeDeleteForm.php b/core/modules/node/lib/Drupal/node/Form/NodeDeleteForm.php
index 164ac5f..5f28721 100644
--- a/core/modules/node/lib/Drupal/node/Form/NodeDeleteForm.php
+++ b/core/modules/node/lib/Drupal/node/Form/NodeDeleteForm.php
@@ -83,7 +83,7 @@ public function getConfirmText() {
   /**
    * {@inheritdoc}
    */
-  public function submit(array $form, array &$form_state) {
+  public function submitForm(array &$form, array &$form_state) {
     $this->entity->delete();
     watchdog('content', '@type: deleted %title.', array('@type' => $this->entity->bundle(), '%title' => $this->entity->label()));
     $node_type_storage = $this->entityManager->getStorage('node_type');
diff --git a/core/modules/node/lib/Drupal/node/Form/NodeTypeDeleteConfirm.php b/core/modules/node/lib/Drupal/node/Form/NodeTypeDeleteConfirm.php
index 8adc575..1ef65aa 100644
--- a/core/modules/node/lib/Drupal/node/Form/NodeTypeDeleteConfirm.php
+++ b/core/modules/node/lib/Drupal/node/Form/NodeTypeDeleteConfirm.php
@@ -83,7 +83,7 @@ public function buildForm(array $form, array &$form_state) {
   /**
    * {@inheritdoc}
    */
-  public function submit(array $form, array &$form_state) {
+  public function submitForm(array &$form, array &$form_state) {
     $this->entity->delete();
     $t_args = array('%name' => $this->entity->label());
     drupal_set_message(t('The content type %name has been deleted.', $t_args));
diff --git a/core/modules/node/lib/Drupal/node/NodeForm.php b/core/modules/node/lib/Drupal/node/NodeForm.php
index 37bb7da..8193695 100644
--- a/core/modules/node/lib/Drupal/node/NodeForm.php
+++ b/core/modules/node/lib/Drupal/node/NodeForm.php
@@ -287,7 +287,7 @@ protected function actions(array $form, array &$form_state) {
         array($this, 'validate'),
       ),
       '#submit' => array(
-        array($this, 'submit'),
+        array($this, 'submitForm'),
         array($this, 'preview'),
       ),
     );
@@ -335,17 +335,18 @@ public function validate(array $form, array &$form_state) {
   }
 
   /**
+   * {@inheritdoc}
+   *
    * Updates the node object by processing the submitted values.
    *
    * This function can be called by a "Next" button of a wizard to update the
    * form state's entity with the current step's values before proceeding to the
    * next step.
-   *
-   * Overrides Drupal\Core\Entity\EntityForm::submit().
    */
-  public function submit(array $form, array &$form_state) {
+  public function submitForm(array &$form, array &$form_state) {
     // Build the node object from the submitted values.
-    $node = parent::submit($form, $form_state);
+    parent::submitForm($form, $form_state);
+    $node = $this->entity;
 
     // Save as a new revision if requested to do so.
     if (!empty($form_state['values']['revision']) && $form_state['values']['revision'] != FALSE) {
@@ -363,8 +364,6 @@ public function submit(array $form, array &$form_state) {
       $function = $module . '_node_submit';
       $function($node, $form, $form_state);
     }
-
-    return $node;
   }
 
   /**
@@ -435,7 +434,6 @@ public function buildEntity(array $form, array &$form_state) {
     return $entity;
   }
 
-
   /**
    * Overrides Drupal\Core\Entity\EntityForm::save().
    */
diff --git a/core/modules/responsive_image/lib/Drupal/responsive_image/Form/ResponsiveImageMappingDeleteForm.php b/core/modules/responsive_image/lib/Drupal/responsive_image/Form/ResponsiveImageMappingDeleteForm.php
index 2f79f57..e6eb5e4 100644
--- a/core/modules/responsive_image/lib/Drupal/responsive_image/Form/ResponsiveImageMappingDeleteForm.php
+++ b/core/modules/responsive_image/lib/Drupal/responsive_image/Form/ResponsiveImageMappingDeleteForm.php
@@ -37,7 +37,7 @@ public function getConfirmText() {
   /**
    * {@inheritdoc}
    */
-  public function submit(array $form, array &$form_state) {
+  public function submitForm(array &$form, array &$form_state) {
     $this->entity->delete();
     drupal_set_message($this->t('Responsive image mapping %label has been deleted.', array('%label' => $this->entity->label())));
     watchdog('responsive_image', 'Responsive image mapping %label has been deleted.', array('%label' => $this->entity->label()), WATCHDOG_NOTICE);
diff --git a/core/modules/responsive_image/lib/Drupal/responsive_image/ResponsiveImageMappingForm.php b/core/modules/responsive_image/lib/Drupal/responsive_image/ResponsiveImageMappingForm.php
index 1b4bb4a..17f8863 100644
--- a/core/modules/responsive_image/lib/Drupal/responsive_image/ResponsiveImageMappingForm.php
+++ b/core/modules/responsive_image/lib/Drupal/responsive_image/ResponsiveImageMappingForm.php
@@ -115,7 +115,7 @@ public function validate(array $form, array &$form_state) {
   }
 
   /**
-   * Overrides Drupal\Core\Entity\EntityForm::save().
+   * {@inheritdoc}
    */
   public function save(array $form, array &$form_state) {
     /** @var \Drupal\responsive_image\ResponsiveImageMappingInterface $responsive_image_mapping */
diff --git a/core/modules/search/lib/Drupal/search/Form/SearchPageDeleteForm.php b/core/modules/search/lib/Drupal/search/Form/SearchPageDeleteForm.php
index c9a5752..7037a38 100644
--- a/core/modules/search/lib/Drupal/search/Form/SearchPageDeleteForm.php
+++ b/core/modules/search/lib/Drupal/search/Form/SearchPageDeleteForm.php
@@ -40,7 +40,7 @@ public function getConfirmText() {
   /**
    * {@inheritdoc}
    */
-  public function submit(array $form, array &$form_state) {
+  public function submitForm(array &$form, array &$form_state) {
     $this->entity->delete();
     $form_state['redirect_route']['route_name'] = 'search.settings';
     drupal_set_message($this->t('The %label search page has been deleted.', array('%label' => $this->entity->label())));
diff --git a/core/modules/search/lib/Drupal/search/Form/SearchPageFormBase.php b/core/modules/search/lib/Drupal/search/Form/SearchPageFormBase.php
index 43fed9c..72a4120 100644
--- a/core/modules/search/lib/Drupal/search/Form/SearchPageFormBase.php
+++ b/core/modules/search/lib/Drupal/search/Form/SearchPageFormBase.php
@@ -163,8 +163,8 @@ public function validate(array $form, array &$form_state) {
   /**
    * {@inheritdoc}
    */
-  public function submit(array $form, array &$form_state) {
-    parent::submit($form, $form_state);
+  public function submitForm(array &$form, array &$form_state) {
+    parent::submitForm($form, $form_state);
 
     if ($this->plugin instanceof PluginFormInterface) {
       $this->plugin->submitConfigurationForm($form, $form_state);
diff --git a/core/modules/shortcut/src/Form/SetCustomize.php b/core/modules/shortcut/src/Form/SetCustomize.php
index 716f7ea..2208857 100644
--- a/core/modules/shortcut/src/Form/SetCustomize.php
+++ b/core/modules/shortcut/src/Form/SetCustomize.php
@@ -89,7 +89,7 @@ protected function actions(array $form, array &$form_state) {
         '#value' => t('Save changes'),
         '#access' => (bool) Element::getVisibleChildren($form['shortcuts']['links']),
         '#submit' => array(
-          array($this, 'submit'),
+          array($this, 'submitForm'),
           array($this, 'save'),
         ),
       ),
diff --git a/core/modules/shortcut/src/Form/ShortcutDeleteForm.php b/core/modules/shortcut/src/Form/ShortcutDeleteForm.php
index b5bbabe..164556b 100644
--- a/core/modules/shortcut/src/Form/ShortcutDeleteForm.php
+++ b/core/modules/shortcut/src/Form/ShortcutDeleteForm.php
@@ -50,7 +50,7 @@ public function getConfirmText() {
   /**
    * {@inheritdoc}
    */
-  public function submit(array $form, array &$form_state) {
+  public function submitForm(array &$form, array &$form_state) {
     $this->entity->delete();
     $form_state['redirect_route'] = array(
       'route_name' => 'shortcut.set_customize',
diff --git a/core/modules/shortcut/src/Form/ShortcutSetDeleteForm.php b/core/modules/shortcut/src/Form/ShortcutSetDeleteForm.php
index 504b81e..8375432 100644
--- a/core/modules/shortcut/src/Form/ShortcutSetDeleteForm.php
+++ b/core/modules/shortcut/src/Form/ShortcutSetDeleteForm.php
@@ -105,7 +105,7 @@ public function buildForm(array $form, array &$form_state) {
   /**
    * {@inheritdoc}
    */
-  public function submit(array $form, array &$form_state) {
+  public function submitForm(array &$form, array &$form_state) {
     $this->entity->delete();
     $form_state['redirect_route']['route_name'] = 'shortcut.set_admin';
     drupal_set_message(t('The shortcut set %title has been deleted.', array('%title' => $this->entity->label())));
diff --git a/core/modules/system/lib/Drupal/system/Form/DateFormatAddForm.php b/core/modules/system/lib/Drupal/system/Form/DateFormatAddForm.php
index b9289a2..957b7fa 100644
--- a/core/modules/system/lib/Drupal/system/Form/DateFormatAddForm.php
+++ b/core/modules/system/lib/Drupal/system/Form/DateFormatAddForm.php
@@ -21,12 +21,4 @@ protected function actions(array $form, array &$form_state) {
     return $actions;
   }
 
-  /**
-   * {@inheritdoc}
-   */
-  public function submit(array $form, array &$form_state) {
-    parent::submit($form, $form_state);
-    drupal_set_message(t('Custom date format added.'));
-  }
-
 }
diff --git a/core/modules/system/lib/Drupal/system/Form/DateFormatDeleteForm.php b/core/modules/system/lib/Drupal/system/Form/DateFormatDeleteForm.php
index 79629fa..52d13fc 100644
--- a/core/modules/system/lib/Drupal/system/Form/DateFormatDeleteForm.php
+++ b/core/modules/system/lib/Drupal/system/Form/DateFormatDeleteForm.php
@@ -71,7 +71,7 @@ public function getCancelRoute() {
   /**
    * {@inheritdoc}
    */
-  public function submit(array $form, array &$form_state) {
+  public function submitForm(array &$form, array &$form_state) {
     $this->entity->delete();
     drupal_set_message(t('Removed date format %format.', array('%format' => $this->entity->label())));
 
diff --git a/core/modules/system/lib/Drupal/system/Form/DateFormatEditForm.php b/core/modules/system/lib/Drupal/system/Form/DateFormatEditForm.php
index 3b25d7e..3cc2b7b 100644
--- a/core/modules/system/lib/Drupal/system/Form/DateFormatEditForm.php
+++ b/core/modules/system/lib/Drupal/system/Form/DateFormatEditForm.php
@@ -35,12 +35,4 @@ protected function actions(array $form, array &$form_state) {
     return $actions;
   }
 
-  /**
-   * {@inheritdoc}
-   */
-  public function submit(array $form, array &$form_state) {
-    parent::submit($form, $form_state);
-    drupal_set_message(t('Custom date format updated.'));
-  }
-
 }
diff --git a/core/modules/system/lib/Drupal/system/Form/DateFormatFormBase.php b/core/modules/system/lib/Drupal/system/Form/DateFormatFormBase.php
index 3dfb81e..57f52bf 100644
--- a/core/modules/system/lib/Drupal/system/Form/DateFormatFormBase.php
+++ b/core/modules/system/lib/Drupal/system/Form/DateFormatFormBase.php
@@ -188,12 +188,21 @@ public function validate(array $form, array &$form_state) {
   /**
    * {@inheritdoc}
    */
-  public function submit(array $form, array &$form_state) {
-    $form_state['redirect_route']['route_name'] = 'system.date_format_list';
+  public function submitForm(array &$form, array &$form_state) {
     $form_state['values']['pattern'][$this->patternType] = trim($form_state['values']['date_format_pattern']);
+    parent::submitForm($form, $form_state);
+  }
 
-    parent::submit($form, $form_state);
-    $this->entity->save();
+  public function save(array $form, array &$form_state) {
+    $form_state['redirect_route']['route_name'] = 'system.date_format_list';
+    $form_state['redirect'] = 'admin/config/regional/date-time';
+    $status = $this->entity->save();
+    if ($status == SAVED_UPDATED) {
+      drupal_set_message(t('Custom date format updated.'));
+    }
+    else {
+      drupal_set_message(t('Custom date format added.'));
+    }
   }
 
 }
diff --git a/core/modules/system/tests/modules/entity_test/lib/Drupal/entity_test/EntityTestDeleteForm.php b/core/modules/system/tests/modules/entity_test/lib/Drupal/entity_test/EntityTestDeleteForm.php
index 5f84846..270cd6e 100644
--- a/core/modules/system/tests/modules/entity_test/lib/Drupal/entity_test/EntityTestDeleteForm.php
+++ b/core/modules/system/tests/modules/entity_test/lib/Drupal/entity_test/EntityTestDeleteForm.php
@@ -34,8 +34,8 @@ public function getQuestion() {
   /**
    * {@inheritdoc}
    */
-  public function submit(array $form, array &$form_state) {
-    parent::submit($form, $form_state);
+  public function submitForm(array &$form, array &$form_state) {
+    parent::submitForm($form, $form_state);
     $entity = $this->entity;
     $entity->delete();
     drupal_set_message(t('%entity_type @id has been deleted.', array('@id' => $entity->id(), '%entity_type' => $entity->getEntityTypeId())));
diff --git a/core/modules/system/tests/modules/entity_test/lib/Drupal/entity_test/EntityTestForm.php b/core/modules/system/tests/modules/entity_test/lib/Drupal/entity_test/EntityTestForm.php
index 849ea17..8b38dc6 100644
--- a/core/modules/system/tests/modules/entity_test/lib/Drupal/entity_test/EntityTestForm.php
+++ b/core/modules/system/tests/modules/entity_test/lib/Drupal/entity_test/EntityTestForm.php
@@ -61,25 +61,16 @@ public function form(array $form, array &$form_state) {
   }
 
   /**
-   * Overrides \Drupal\Core\Entity\EntityForm::submit().
+   * {@inheritdoc}
    */
-  public function submit(array $form, array &$form_state) {
-    // Build the entity object from the submitted values.
-    $entity = parent::submit($form, $form_state);
+  public function save(array $form, array &$form_state) {
+    $entity = $this->entity;
 
     // Save as a new revision if requested to do so.
     if (!empty($form_state['values']['revision'])) {
       $entity->setNewRevision();
     }
 
-    return $entity;
-  }
-
-  /**
-   * Overrides Drupal\Core\Entity\EntityForm::save().
-   */
-  public function save(array $form, array &$form_state) {
-    $entity = $this->entity;
     $is_new = $entity->isNew();
     $entity->save();
 
diff --git a/core/modules/taxonomy/lib/Drupal/taxonomy/Form/TermDeleteForm.php b/core/modules/taxonomy/lib/Drupal/taxonomy/Form/TermDeleteForm.php
index 58fbb12..061ef55 100644
--- a/core/modules/taxonomy/lib/Drupal/taxonomy/Form/TermDeleteForm.php
+++ b/core/modules/taxonomy/lib/Drupal/taxonomy/Form/TermDeleteForm.php
@@ -57,7 +57,7 @@ public function getConfirmText() {
   /**
    * {@inheritdoc}
    */
-  public function submit(array $form, array &$form_state) {
+  public function submitForm(array &$form, array &$form_state) {
     $this->entity->delete();
     $storage = $this->entityManager->getStorage('taxonomy_vocabulary');
     $vocabulary = $storage->load($this->entity->bundle());
diff --git a/core/modules/taxonomy/lib/Drupal/taxonomy/Form/VocabularyDeleteForm.php b/core/modules/taxonomy/lib/Drupal/taxonomy/Form/VocabularyDeleteForm.php
index 8032901..d159cce 100644
--- a/core/modules/taxonomy/lib/Drupal/taxonomy/Form/VocabularyDeleteForm.php
+++ b/core/modules/taxonomy/lib/Drupal/taxonomy/Form/VocabularyDeleteForm.php
@@ -55,7 +55,7 @@ public function getConfirmText() {
   /**
    * {@inheritdoc}
    */
-  public function submit(array $form, array &$form_state) {
+  public function submitForm(array &$form, array &$form_state) {
     $this->entity->delete();
     drupal_set_message($this->t('Deleted vocabulary %name.', array('%name' => $this->entity->label())));
     watchdog('taxonomy', 'Deleted vocabulary %name.', array('%name' => $this->entity->label()), WATCHDOG_NOTICE);
diff --git a/core/modules/taxonomy/lib/Drupal/taxonomy/Form/VocabularyResetForm.php b/core/modules/taxonomy/lib/Drupal/taxonomy/Form/VocabularyResetForm.php
index bae776c..93d5bd4 100644
--- a/core/modules/taxonomy/lib/Drupal/taxonomy/Form/VocabularyResetForm.php
+++ b/core/modules/taxonomy/lib/Drupal/taxonomy/Form/VocabularyResetForm.php
@@ -80,8 +80,10 @@ public function getConfirmText() {
   /**
    * {@inheritdoc}
    */
-  public function save(array $form, array &$form_state) {
+  public function submitForm(array &$form, array &$form_state) {
+    parent::submitForm($form, $form_state);
     $this->termStorage->resetWeights($this->entity->id());
+
     drupal_set_message($this->t('Reset vocabulary %name to alphabetical order.', array('%name' => $this->entity->label())));
     watchdog('taxonomy', 'Reset vocabulary %name to alphabetical order.', array('%name' => $this->entity->label()), WATCHDOG_NOTICE);
     $form_state['redirect_route'] = $this->entity->urlInfo('edit-form');
diff --git a/core/modules/user/lib/Drupal/user/AccountForm.php b/core/modules/user/lib/Drupal/user/AccountForm.php
index f85fca2..e4da8fc 100644
--- a/core/modules/user/lib/Drupal/user/AccountForm.php
+++ b/core/modules/user/lib/Drupal/user/AccountForm.php
@@ -376,8 +376,8 @@ public function validate(array $form, array &$form_state) {
   /**
    * {@inheritdoc}
    */
-  public function submit(array $form, array &$form_state) {
-    parent::submit($form, $form_state);
+  public function submitForm(array &$form, array &$form_state) {
+    parent::submitForm($form, $form_state);
 
     $user = $this->getEntity($form_state);
     // If there's a session set to the users id, remove the password reset tag
diff --git a/core/modules/user/lib/Drupal/user/Form/UserCancelForm.php b/core/modules/user/lib/Drupal/user/Form/UserCancelForm.php
index 9f76e1e..e9a4c5e 100644
--- a/core/modules/user/lib/Drupal/user/Form/UserCancelForm.php
+++ b/core/modules/user/lib/Drupal/user/Form/UserCancelForm.php
@@ -151,7 +151,7 @@ public function buildForm(array $form, array &$form_state) {
   /**
    * {@inheritdoc}
    */
-  public function submit(array $form, array &$form_state) {
+  public function submitForm(array &$form, array &$form_state) {
     // Cancel account immediately, if the current user has administrative
     // privileges, no confirmation mail shall be sent, and the user does not
     // attempt to cancel the own account.
diff --git a/core/modules/user/lib/Drupal/user/Form/UserMultipleCancelConfirm.php b/core/modules/user/lib/Drupal/user/Form/UserMultipleCancelConfirm.php
index 8e99476..aa4511b 100644
--- a/core/modules/user/lib/Drupal/user/Form/UserMultipleCancelConfirm.php
+++ b/core/modules/user/lib/Drupal/user/Form/UserMultipleCancelConfirm.php
@@ -203,7 +203,7 @@ public function submitForm(array &$form, array &$form_state) {
           $admin_form->setEntity($account);
           // Calling this directly required to init form object with $account.
           $admin_form->buildForm($admin_form_mock, $admin_form_state, $this->request);
-          $admin_form->submit($admin_form_mock, $admin_form_state);
+          $admin_form->submitForm($admin_form_mock, $admin_form_state);
         }
         else {
           user_cancel($form_state['values'], $uid, $form_state['values']['user_cancel_method']);
diff --git a/core/modules/user/lib/Drupal/user/Form/UserRoleDelete.php b/core/modules/user/lib/Drupal/user/Form/UserRoleDelete.php
index bbb3614..1449e35 100644
--- a/core/modules/user/lib/Drupal/user/Form/UserRoleDelete.php
+++ b/core/modules/user/lib/Drupal/user/Form/UserRoleDelete.php
@@ -40,7 +40,7 @@ public function getConfirmText() {
   /**
    * {@inheritdoc}
    */
-  public function submit(array $form, array &$form_state) {
+  public function submitForm(array &$form, array &$form_state) {
     $this->entity->delete();
     watchdog('user', 'Role %name has been deleted.', array('%name' => $this->entity->label()));
     drupal_set_message($this->t('Role %name has been deleted.', array('%name' => $this->entity->label())));
diff --git a/core/modules/user/lib/Drupal/user/RegisterForm.php b/core/modules/user/lib/Drupal/user/RegisterForm.php
index 30f3018..e8eb2c7 100644
--- a/core/modules/user/lib/Drupal/user/RegisterForm.php
+++ b/core/modules/user/lib/Drupal/user/RegisterForm.php
@@ -69,9 +69,9 @@ protected function actions(array $form, array &$form_state) {
   }
 
   /**
-   * Overrides Drupal\Core\Entity\EntityForm::submit().
+   * {@inheritdoc}
    */
-  public function submit(array $form, array &$form_state) {
+  public function submitForm(array &$form, array &$form_state) {
     $admin = $form_state['values']['administer_users'];
 
     if (!\Drupal::config('user.settings')->get('verify_mail') || $admin) {
@@ -87,11 +87,11 @@ public function submit(array $form, array &$form_state) {
     $form_state['values']['pass'] = $pass;
     $form_state['values']['init'] = $form_state['values']['mail'];
 
-    parent::submit($form, $form_state);
+    parent::submitForm($form, $form_state);
   }
 
   /**
-   * Overrides Drupal\Core\Entity\EntityForm::submit().
+   * {@inheritdoc}
    */
   public function save(array $form, array &$form_state) {
     $account = $this->entity;
diff --git a/core/modules/views_ui/lib/Drupal/views_ui/Form/BreakLockForm.php b/core/modules/views_ui/lib/Drupal/views_ui/Form/BreakLockForm.php
index 52501ef..2a59346 100644
--- a/core/modules/views_ui/lib/Drupal/views_ui/Form/BreakLockForm.php
+++ b/core/modules/views_ui/lib/Drupal/views_ui/Form/BreakLockForm.php
@@ -109,7 +109,7 @@ public function buildForm(array $form, array &$form_state) {
   /**
    * {@inheritdoc}
    */
-  public function submit(array $form, array &$form_state) {
+  public function submitForm(array &$form, array &$form_state) {
     $this->tempStore->delete($this->entity->id());
     $form_state['redirect_route'] = $this->entity->urlInfo('edit-form');
     drupal_set_message($this->t('The lock has been broken and you may now edit this view.'));
diff --git a/core/modules/views_ui/lib/Drupal/views_ui/ViewAddForm.php b/core/modules/views_ui/lib/Drupal/views_ui/ViewAddForm.php
index fac46e3..d36e071 100644
--- a/core/modules/views_ui/lib/Drupal/views_ui/ViewAddForm.php
+++ b/core/modules/views_ui/lib/Drupal/views_ui/ViewAddForm.php
@@ -148,7 +148,8 @@ public function form(array $form, array &$form_state) {
   protected function actions(array $form, array &$form_state) {
     $actions = parent::actions($form, $form_state);
     $actions['submit']['#value'] = $this->t('Save and edit');
-
+    // Remove EntityFormController::save() form the submission handlers.
+    $actions['submit']['#submit'] = array(array($this, 'submitForm'));
     $actions['cancel'] = array(
       '#type' => 'submit',
       '#value' => $this->t('Cancel'),
@@ -180,11 +181,11 @@ public function validate(array $form, array &$form_state) {
   /**
    * {@inheritdoc}
    */
-  public function submit(array $form, array &$form_state) {
+  public function submitForm(array &$form, array &$form_state) {
     try {
       /** @var $wizard \Drupal\views\Plugin\views\wizard\WizardInterface */
       $wizard = $form_state['wizard_instance'];
-      $view = $wizard->createView($form, $form_state);
+      $this->entity = $wizard->createView($form, $form_state);
     }
     // @todo Figure out whether it really makes sense to throw and catch exceptions on the wizard.
     catch (WizardException $e) {
@@ -192,9 +193,9 @@ public function submit(array $form, array &$form_state) {
       $form_state['redirect_route']['route_name'] = 'views_ui.list';
       return;
     }
-    $view->save();
+    $this->entity->save();
 
-    $form_state['redirect_route'] = $view->urlInfo('edit-form');
+    $form_state['redirect_route'] = $this->entity->urlInfo('edit-form');
   }
 
   /**
diff --git a/core/modules/views_ui/lib/Drupal/views_ui/ViewCloneForm.php b/core/modules/views_ui/lib/Drupal/views_ui/ViewCloneForm.php
index 2ec467c..1048228 100644
--- a/core/modules/views_ui/lib/Drupal/views_ui/ViewCloneForm.php
+++ b/core/modules/views_ui/lib/Drupal/views_ui/ViewCloneForm.php
@@ -57,24 +57,28 @@ protected function actions(array $form, array &$form_state) {
       '#type' => 'submit',
       '#value' => $this->t('Clone'),
       '#submit' => array(
-        array($this, 'submit'),
+        array($this, 'submitForm'),
+        array($this, 'cloneView'),
       ),
     );
     return $actions;
   }
 
   /**
-   * {@inheritdoc}
+   * Form submission handler for the 'clone' action.
+   *
+   * @param array $form
+   *   An associative array containing the structure of the form.
+   * @param array $form_state
+   *   A reference to a keyed array containing the current state of the form.
    */
-  public function submit(array $form, array &$form_state) {
-    $original = parent::submit($form, $form_state);
-    $this->entity = $original->createDuplicate();
+  public function cloneView(array $form, array &$form_state) {
+    $this->entity = $this->entity->createDuplicate();
     $this->entity->set('id', $form_state['values']['id']);
     $this->entity->save();
 
     // Redirect the user to the view admin form.
     $form_state['redirect_route'] = $this->entity->urlInfo('edit-form');
-    return $this->entity;
   }
 
 }
diff --git a/core/modules/views_ui/lib/Drupal/views_ui/ViewDeleteForm.php b/core/modules/views_ui/lib/Drupal/views_ui/ViewDeleteForm.php
index 6402190..5dd8163 100644
--- a/core/modules/views_ui/lib/Drupal/views_ui/ViewDeleteForm.php
+++ b/core/modules/views_ui/lib/Drupal/views_ui/ViewDeleteForm.php
@@ -40,9 +40,7 @@ public function getConfirmText() {
   /**
    * {@inheritdoc}
    */
-  public function submit(array $form, array &$form_state) {
-    parent::submit($form, $form_state);
-
+  public function submitForm(array &$form, array &$form_state) {
     $this->entity->delete();
     $form_state['redirect_route']['route_name'] = 'views_ui.list';
     drupal_set_message($this->t('View %name deleted',array('%name' => $this->entity->label())));
diff --git a/core/modules/views_ui/lib/Drupal/views_ui/ViewEditForm.php b/core/modules/views_ui/lib/Drupal/views_ui/ViewEditForm.php
index 39e82d1..113035e 100644
--- a/core/modules/views_ui/lib/Drupal/views_ui/ViewEditForm.php
+++ b/core/modules/views_ui/lib/Drupal/views_ui/ViewEditForm.php
@@ -256,9 +256,7 @@ public function validate(array $form, array &$form_state) {
   /**
    * {@inheritdoc}
    */
-  public function submit(array $form, array &$form_state) {
-    parent::submit($form, $form_state);
-
+  public function save(array $form, array &$form_state) {
     $view = $this->entity;
     $executable = $view->getExecutable();