diff --git a/core/modules/field_layout/config/schema/field_layout.schema.yml b/core/modules/field_layout/config/schema/field_layout.schema.yml
index 3b53b3f..185fb4e 100644
--- a/core/modules/field_layout/config/schema/field_layout.schema.yml
+++ b/core/modules/field_layout/config/schema/field_layout.schema.yml
@@ -6,7 +6,7 @@ core.entity_form_display.*.*.*.third_party.field_layout:
 
 field_layout.third_party_settings:
   type: mapping
-  label: 'Per view mode field layout settings'
+  label: 'Per-view-mode field layout settings'
   mapping:
     id:
       type: string
diff --git a/core/modules/field_layout/field_layout.install b/core/modules/field_layout/field_layout.install
index 6f94674..5956bf1 100644
--- a/core/modules/field_layout/field_layout.install
+++ b/core/modules/field_layout/field_layout.install
@@ -8,15 +8,15 @@
 use Drupal\Core\Cache\Cache;
 use Drupal\Core\Entity\Entity\EntityFormDisplay;
 use Drupal\Core\Entity\Entity\EntityViewDisplay;
-use Drupal\Core\Entity\EntityInterface;
+use Drupal\field_layout\Display\EntityDisplayWithLayoutInterface;
 
 /**
  * Implements hook_install().
  */
 function field_layout_install() {
-  // Save each entity display in order to trigger ::preSave().
-  $entity_save = function (EntityInterface $entity) {
-    $entity->save();
+  // Ensure each entity display has a layout.
+  $entity_save = function (EntityDisplayWithLayoutInterface $entity) {
+    $entity->ensureLayout()->save();
   };
   array_map($entity_save, EntityViewDisplay::loadMultiple());
   array_map($entity_save, EntityFormDisplay::loadMultiple());
@@ -24,3 +24,19 @@ function field_layout_install() {
   // Invalidate the render cache since all content will now have a layout.
   Cache::invalidateTags(['rendered']);
 }
+
+/**
+ * Implements hook_uninstall().
+ */
+function field_layout_uninstall() {
+  // Reset each entity display to use the one-column layout to best approximate
+  // the absence of layouts.
+  $entity_save = function (EntityDisplayWithLayoutInterface $entity) {
+    $entity->setLayoutId('layout_onecol')->save();
+  };
+  array_map($entity_save, EntityViewDisplay::loadMultiple());
+  array_map($entity_save, EntityFormDisplay::loadMultiple());
+
+  // Invalidate the render cache since all content will no longer have a layout.
+  Cache::invalidateTags(['rendered']);
+}
diff --git a/core/modules/field_layout/field_layout.layouts.yml b/core/modules/field_layout/field_layout.layouts.yml
index 2852708..7f51a69 100644
--- a/core/modules/field_layout/field_layout.layouts.yml
+++ b/core/modules/field_layout/field_layout.layouts.yml
@@ -1,17 +1,18 @@
-field_layout_onecol:
+# @todo Move to layout_discovery in https://www.drupal.org/node/2840832.
+layout_onecol:
   label: 'One column'
   path: layouts/onecol
-  template: field-layout--onecol
+  template: layout--onecol
   category: 'Columns: 1'
   default_region: content
   regions:
     content:
       label: Content
-field_layout_twocol:
+layout_twocol:
   label: 'Two column'
   path: layouts/twocol
-  template: field-layout--twocol
-  library: field_layout/drupal.field_layout.twocol
+  template: layout--twocol
+  library: field_layout/drupal.layout.twocol
   category: 'Columns: 2'
   default_region: left
   regions:
diff --git a/core/modules/field_layout/field_layout.libraries.yml b/core/modules/field_layout/field_layout.libraries.yml
index d87df5e..aafe7ee 100644
--- a/core/modules/field_layout/field_layout.libraries.yml
+++ b/core/modules/field_layout/field_layout.libraries.yml
@@ -1,4 +1,4 @@
-drupal.field_layout.twocol:
+drupal.layout.twocol:
   version: VERSION
   css:
     layout:
diff --git a/core/modules/field_layout/field_layout.module b/core/modules/field_layout/field_layout.module
index e076ca7..5a5fa11 100644
--- a/core/modules/field_layout/field_layout.module
+++ b/core/modules/field_layout/field_layout.module
@@ -51,7 +51,7 @@ function field_layout_entity_type_alter(array &$entity_types) {
 function field_layout_entity_view_alter(array &$build, EntityInterface $entity, EntityViewDisplayInterface $display) {
   if ($display instanceof EntityDisplayWithLayoutInterface) {
     \Drupal::classResolver()->getInstanceFromDefinition(FieldLayoutBuilder::class)
-      ->build($build, $display, 'view');
+      ->buildView($build, $display);
   }
 }
 
@@ -63,7 +63,7 @@ function field_layout_form_alter(&$form, FormStateInterface $form_state, $form_i
   if ($form_object instanceof ContentEntityFormInterface && $display = $form_object->getFormDisplay($form_state)) {
     if ($display instanceof EntityDisplayWithLayoutInterface) {
       \Drupal::classResolver()->getInstanceFromDefinition(FieldLayoutBuilder::class)
-        ->build($form, $display, 'form');
+        ->buildForm($form, $display);
     }
   }
 }
diff --git a/core/modules/field_layout/layouts/onecol/field-layout--onecol.html.twig b/core/modules/field_layout/layouts/onecol/layout--onecol.html.twig
similarity index 66%
rename from core/modules/field_layout/layouts/onecol/field-layout--onecol.html.twig
rename to core/modules/field_layout/layouts/onecol/layout--onecol.html.twig
index cce4893..69fed03 100644
--- a/core/modules/field_layout/layouts/onecol/field-layout--onecol.html.twig
+++ b/core/modules/field_layout/layouts/onecol/layout--onecol.html.twig
@@ -1,7 +1,7 @@
 {#
 /**
  * @file
- * Default theme implementation to display a one column layout.
+ * Default theme implementation to display a one-column layout.
  *
  * Available variables:
  * - content: The content for this layout.
@@ -12,12 +12,12 @@
 #}
 {%
 set classes = [
-'field-layout--onecol',
+'layout--onecol',
 ]
 %}
 {% if content %}
 <div{{ attributes.addClass(classes) }}>
-  <div class="field-layout-region field-layout-region--content">
+  <div class="layout-region layout-region--content">
     {{ content }}
   </div>
 </div>
diff --git a/core/modules/field_layout/layouts/twocol/field-layout--twocol.html.twig b/core/modules/field_layout/layouts/twocol/layout--twocol.html.twig
similarity index 61%
rename from core/modules/field_layout/layouts/twocol/field-layout--twocol.html.twig
rename to core/modules/field_layout/layouts/twocol/layout--twocol.html.twig
index 4dffc01..8e54d30 100644
--- a/core/modules/field_layout/layouts/twocol/field-layout--twocol.html.twig
+++ b/core/modules/field_layout/layouts/twocol/layout--twocol.html.twig
@@ -1,7 +1,7 @@
 {#
 /**
  * @file
- * Default theme implementation to display a two column layout.
+ * Default theme implementation to display a two-column layout.
  *
  * Available variables:
  * - content: The content for this layout.
@@ -12,16 +12,16 @@
 #}
 {%
 set classes = [
-'field-layout--twocol',
+'layout--twocol',
 ]
 %}
 {% if content %}
   <div{{ attributes.addClass(classes) }}>
-    <div class="field-layout-region field-layout-region--left">
+    <div class="layout-region layout-region--left">
       {{ content.left }}
     </div>
 
-    <div class="field-layout-region field-layout-region--right">
+    <div class="layout-region layout-region--right">
       {{ content.right }}
     </div>
   </div>
diff --git a/core/modules/field_layout/layouts/twocol/twocol.layout.css b/core/modules/field_layout/layouts/twocol/twocol.layout.css
index 8e2f623..78a447d 100644
--- a/core/modules/field_layout/layouts/twocol/twocol.layout.css
+++ b/core/modules/field_layout/layouts/twocol/twocol.layout.css
@@ -1,14 +1,14 @@
-.field-layout--twocol {
+.layout--twocol {
   display: flex;
   flex-wrap: wrap;
   justify-content: space-between;
 }
-.field-layout--twocol > .field-layout-region {
+.layout--twocol > .layout-region {
   flex: 0 1 50%;
   max-width: 50%;
 }
 
-.field-layout--twocol > .field-layout-region--left {
+.layout--twocol > .layout-region--left {
   max-width: calc(50% - 10px);
   margin-right: 10px;
 }
diff --git a/core/modules/field_layout/src/Display/EntityDisplayWithLayoutInterface.php b/core/modules/field_layout/src/Display/EntityDisplayWithLayoutInterface.php
index 54a2d52..3bee65e 100644
--- a/core/modules/field_layout/src/Display/EntityDisplayWithLayoutInterface.php
+++ b/core/modules/field_layout/src/Display/EntityDisplayWithLayoutInterface.php
@@ -64,4 +64,15 @@ public function setLayout(LayoutInterface $layout);
    */
   public function getLayout();
 
+  /**
+   * Ensures this entity has a layout.
+   *
+   * @param string $default_layout_id
+   *   (optional) The layout ID to use as a default. Defaults to
+   *   'layout_onecol'.
+   *
+   * @return $this
+   */
+  public function ensureLayout($default_layout_id = 'layout_onecol');
+
 }
diff --git a/core/modules/field_layout/src/Entity/FieldLayoutEntityDisplayTrait.php b/core/modules/field_layout/src/Entity/FieldLayoutEntityDisplayTrait.php
index 201881e..91cf936 100644
--- a/core/modules/field_layout/src/Entity/FieldLayoutEntityDisplayTrait.php
+++ b/core/modules/field_layout/src/Entity/FieldLayoutEntityDisplayTrait.php
@@ -7,6 +7,10 @@
 
 /**
  * Provides shared code for entity displays.
+ *
+ * Both EntityViewDisplay and EntityFormDisplay must maintain their parent
+ * hierarchy, while being identically enhanced by Field Layout. This trait
+ * contains the code they both share.
  */
 trait FieldLayoutEntityDisplayTrait {
 
@@ -41,6 +45,17 @@ public function getLayoutSettings() {
    * Implements \Drupal\field_layout\Display\EntityDisplayWithLayoutInterface::setLayoutId().
    */
   public function setLayoutId($layout_id, array $layout_settings = []) {
+    if ($this->getLayoutId() !== $layout_id) {
+      // @todo Devise a mechanism for mapping old regions to new ones in
+      //   https://www.drupal.org/node/2796877.
+      $new_region = $this->getLayoutDefinition($layout_id)->getDefaultRegion();
+      foreach ($this->getComponents() as $name => $component) {
+        if (isset($component['region']) && !isset($layout_regions[$component['region']])) {
+          $component['region'] = $new_region;
+          $this->setComponent($name, $component);
+        }
+      }
+    }
     $this->setThirdPartySetting('field_layout', 'id', $layout_id);
     $this->setThirdPartySetting('field_layout', 'settings', $layout_settings);
     return $this;
@@ -73,27 +88,21 @@ protected function init() {
    * Overrides \Drupal\Core\Entity\EntityDisplayBase::preSave().
    */
   public function preSave(EntityStorageInterface $storage) {
-    $this->ensureLayout();
-
     parent::preSave($storage);
 
     // Ensure the plugin configuration is updated. Once layouts are no longer
     // stored as third party settings, this will be handled by the code in
     // \Drupal\Core\Config\Entity\ConfigEntityBase::preSave() that handles
     // \Drupal\Core\Entity\EntityWithPluginCollectionInterface.
-    $this->setLayout($this->getLayout());
+    if ($this->getLayoutId()) {
+      $this->setLayout($this->getLayout());
+    }
   }
 
   /**
-   * Ensures this entity has a layout.
-   *
-   * @param string $default_layout_id
-   *   (optional) The layout ID to use as a default. Defaults to
-   *   'field_layout_onecol'.
-   *
-   * @return $this
+   * {@inheritdoc}
    */
-  protected function ensureLayout($default_layout_id = 'field_layout_onecol') {
+  public function ensureLayout($default_layout_id = 'layout_onecol') {
     if (!$this->getLayoutId()) {
       $this->setLayoutId($default_layout_id);
     }
@@ -104,9 +113,9 @@ protected function ensureLayout($default_layout_id = 'field_layout_onecol') {
   /**
    * Overrides \Drupal\Core\Entity\EntityDisplayBase::calculateDependencies().
    *
-   * @todo Remove once https://www.drupal.org/node/2821191 is resolved.
-   *
    * @see \Drupal\Core\Plugin\PluginDependencyTrait::calculatePluginDependencies()
+   *
+   * @todo Remove once https://www.drupal.org/node/2821191 is resolved.
    */
   public function calculateDependencies() {
     parent::calculateDependencies();
diff --git a/core/modules/field_layout/src/Entity/FieldLayoutEntityFormDisplay.php b/core/modules/field_layout/src/Entity/FieldLayoutEntityFormDisplay.php
index a6a4f2d..c58938e 100644
--- a/core/modules/field_layout/src/Entity/FieldLayoutEntityFormDisplay.php
+++ b/core/modules/field_layout/src/Entity/FieldLayoutEntityFormDisplay.php
@@ -14,11 +14,10 @@ class FieldLayoutEntityFormDisplay extends EntityFormDisplay implements EntityDi
 
   /**
    * {@inheritdoc}
-   *
-   * This cannot be provided by the trait due to https://bugs.php.net/bug.php?id=71414
-   * which is fixed in PHP 7.0.6.
    */
   public function getDefaultRegion() {
+    // This cannot be provided by the trait due to
+    // https://bugs.php.net/bug.php?id=71414 which is fixed in PHP 7.0.6.
     return $this->getLayoutDefinition($this->getLayoutId())->getDefaultRegion();
   }
 
diff --git a/core/modules/field_layout/src/Entity/FieldLayoutEntityViewDisplay.php b/core/modules/field_layout/src/Entity/FieldLayoutEntityViewDisplay.php
index e578686..4f0c274 100644
--- a/core/modules/field_layout/src/Entity/FieldLayoutEntityViewDisplay.php
+++ b/core/modules/field_layout/src/Entity/FieldLayoutEntityViewDisplay.php
@@ -14,11 +14,10 @@ class FieldLayoutEntityViewDisplay extends EntityViewDisplay implements EntityDi
 
   /**
    * {@inheritdoc}
-   *
-   * This cannot be provided by the trait due to https://bugs.php.net/bug.php?id=71414
-   * which is fixed in PHP 7.0.6.
    */
   public function getDefaultRegion() {
+    // This cannot be provided by the trait due to
+    // https://bugs.php.net/bug.php?id=71414 which is fixed in PHP 7.0.6.
     return $this->getLayoutDefinition($this->getLayoutId())->getDefaultRegion();
   }
 
diff --git a/core/modules/field_layout/src/FieldLayoutBuilder.php b/core/modules/field_layout/src/FieldLayoutBuilder.php
index 1fbb53a..41582c1 100644
--- a/core/modules/field_layout/src/FieldLayoutBuilder.php
+++ b/core/modules/field_layout/src/FieldLayoutBuilder.php
@@ -29,7 +29,7 @@ class FieldLayoutBuilder implements ContainerInjectionInterface {
   protected $entityFieldManager;
 
   /**
-   * FieldLayoutBuilder constructor.
+   * Constructs a new FieldLayoutBuilder.
    *
    * @param \Drupal\Core\Layout\LayoutPluginManagerInterface $layout_plugin_manager
    *   The layout plugin manager.
@@ -59,34 +59,46 @@ public static function create(ContainerInterface $container) {
    * @param \Drupal\field_layout\Display\EntityDisplayWithLayoutInterface $display
    *   The entity display holding the display options configured for the entity
    *   components.
-   * @param string $display_context
-   *   The display context, either 'form' or 'view'. If in a 'form' context, an
-   *   alternate method will be used to render fields in their regions.
    */
-  public function build(array &$build, EntityDisplayWithLayoutInterface $display, $display_context) {
+  public function buildView(array &$build, EntityDisplayWithLayoutInterface $display) {
     $layout_definition = $this->layoutPluginManager->getDefinition($display->getLayoutId(), FALSE);
-    if ($layout_definition && $fields = $this->getFields($build, $display, $display_context)) {
+    if ($layout_definition && $fields = $this->getFields($build, $display, 'view')) {
+      // Add the regions to the $build in the correct order.
+      $regions = array_fill_keys($layout_definition->getRegionNames(), []);
+
+      foreach ($fields as $name => $field) {
+        // Move the field from the top-level of $build into a region-specific
+        // section.
+        $regions[$field['region']][$name] = $build[$name];
+        unset($build[$name]);
+      }
+      $build['field_layout'] = $display->getLayout()->build($regions);
+    }
+  }
+
+  /**
+   * Applies the layout to an entity form.
+   *
+   * @param array $build
+   *   A renderable array representing the entity content or form.
+   * @param \Drupal\field_layout\Display\EntityDisplayWithLayoutInterface $display
+   *   The entity display holding the display options configured for the entity
+   *   components.
+   */
+  public function buildForm(array &$build, EntityDisplayWithLayoutInterface $display) {
+    $layout_definition = $this->layoutPluginManager->getDefinition($display->getLayoutId(), FALSE);
+    if ($layout_definition && $fields = $this->getFields($build, $display, 'form')) {
       // Add the regions to the $build in the correct order.
       $fill = [];
-      if ($display_context === 'form') {
-        $fill['#process'][] = '\Drupal\Core\Render\Element\RenderElement::processGroup';
-        $fill['#pre_render'][] = '\Drupal\Core\Render\Element\RenderElement::preRenderGroup';
-      }
+      $fill['#process'][] = '\Drupal\Core\Render\Element\RenderElement::processGroup';
+      $fill['#pre_render'][] = '\Drupal\Core\Render\Element\RenderElement::preRenderGroup';
       $regions = array_fill_keys($layout_definition->getRegionNames(), $fill);
 
       foreach ($fields as $name => $field) {
-        // If this is a form, #group can be used to relocate the fields. This
+        // As this is a form, #group can be used to relocate the fields. This
         // avoids breaking hook_form_alter() implementations by not actually
         // moving the field in the form structure.
-        if ($display_context === 'form') {
-          $build[$name]['#group'] = $field['region'];
-        }
-        // Otherwise, move the field from the top-level of $build into a
-        // region-specific section.
-        else {
-          $regions[$field['region']][$name] = $build[$name];
-          unset($build[$name]);
-        }
+        $build[$name]['#group'] = $field['region'];
       }
       $build['field_layout'] = $display->getLayout()->build($regions);
     }
diff --git a/core/modules/field_layout/src/Form/FieldLayoutEntityDisplayFormTrait.php b/core/modules/field_layout/src/Form/FieldLayoutEntityDisplayFormTrait.php
index 4f6b52e..b1256fb 100644
--- a/core/modules/field_layout/src/Form/FieldLayoutEntityDisplayFormTrait.php
+++ b/core/modules/field_layout/src/Form/FieldLayoutEntityDisplayFormTrait.php
@@ -9,6 +9,10 @@
 
 /**
  * Provides shared code for entity display forms.
+ *
+ * Both EntityViewDisplayEditForm and EntityFormDisplayEditForm must maintain
+ * their parent hierarchy, while being identically enhanced by Field Layout.
+ * This trait contains the code they both share.
  */
 trait FieldLayoutEntityDisplayFormTrait {
 
@@ -158,40 +162,7 @@ public function submitForm(array &$form, FormStateInterface $form_state) {
       $layout_plugin->submitConfigurationForm($form['field_layouts']['settings_wrapper']['layout_settings'], SubformState::createForSubform($form['field_layouts']['settings_wrapper']['layout_settings'], $form, $form_state));
     }
 
-    // If the layout is changing the regions will also change, update the
-    // placement of all fields.
-    if ($this->updateLayout($entity, $form_state)) {
-      // @todo Devise a mechanism for mapping old regions to new ones in
-      //   https://www.drupal.org/node/2796877.
-      $new_region = $entity->getDefaultRegion();
-      foreach ($form_state->getValue('fields') as $field_name => $values) {
-        if (($component = $entity->getComponent($field_name)) && $new_region !== 'hidden') {
-          $component['region'] = $new_region;
-          $entity->setComponent($field_name, $component);
-        }
-        else {
-          $entity->removeComponent($field_name);
-        }
-      }
-    }
-  }
-
-  /**
-   * Updates the entity with a new layout.
-   *
-   * @param \Drupal\field_layout\Display\EntityDisplayWithLayoutInterface $entity
-   *   The display entity.
-   * @param \Drupal\Core\Form\FormStateInterface $form_state
-   *   The current form state.
-   *
-   * @return bool
-   *   Returns TRUE if the layout has changed, FALSE if it is the same.
-   */
-  protected function updateLayout(EntityDisplayWithLayoutInterface $entity, FormStateInterface $form_state) {
-    $old_layout = $entity->getLayoutId();
-    $new_layout = $form_state->getValue('field_layout');
-    $entity->setLayout($this->getLayout($entity, $form_state));
-    return $old_layout !== $new_layout;
+    $entity->setLayout($layout_plugin);
   }
 
   /**
diff --git a/core/modules/field_layout/tests/src/Functional/FieldLayoutTest.php b/core/modules/field_layout/tests/src/Functional/FieldLayoutTest.php
index 35b4bdd..683ccd2 100644
--- a/core/modules/field_layout/tests/src/Functional/FieldLayoutTest.php
+++ b/core/modules/field_layout/tests/src/Functional/FieldLayoutTest.php
@@ -47,10 +47,10 @@ protected function setUp() {
    * Tests an entity type that has fields shown by default.
    */
   public function testNodeView() {
-    // By default, the one column layout is used.
+    // By default, the one-column layout is used.
     $this->drupalGet('node/1');
-    $this->assertSession()->elementExists('css', '.field-layout--onecol');
-    $this->assertSession()->elementExists('css', '.field-layout-region--content .field--name-body');
+    $this->assertSession()->elementExists('css', '.layout--onecol');
+    $this->assertSession()->elementExists('css', '.layout-region--content .field--name-body');
 
     $this->drupalGet('admin/structure/types/manage/article/display');
     $this->assertEquals(['Content', 'Disabled'], $this->getRegionTitles());
diff --git a/core/modules/field_layout/tests/src/FunctionalJavascript/FieldLayoutTest.php b/core/modules/field_layout/tests/src/FunctionalJavascript/FieldLayoutTest.php
index adc176f..1336a70 100644
--- a/core/modules/field_layout/tests/src/FunctionalJavascript/FieldLayoutTest.php
+++ b/core/modules/field_layout/tests/src/FunctionalJavascript/FieldLayoutTest.php
@@ -47,9 +47,9 @@ protected function setUp() {
   public function testEntityViewModes() {
     // By default, the field is not visible.
     $this->drupalGet('entity_test/1/test');
-    $this->assertSession()->elementNotExists('css', '.field-layout-region--content .field--name-field-test-text');
+    $this->assertSession()->elementNotExists('css', '.layout-region--content .field--name-field-test-text');
     $this->drupalGet('entity_test/1');
-    $this->assertSession()->elementNotExists('css', '.field-layout-region--content .field--name-field-test-text');
+    $this->assertSession()->elementNotExists('css', '.layout-region--content .field--name-field-test-text');
 
     // Change the layout for the "test" view mode. See
     // core.entity_view_mode.entity_test.test.yml.
@@ -65,26 +65,26 @@ public function testEntityViewModes() {
 
     // Each view mode has a different layout.
     $this->drupalGet('entity_test/1/test');
-    $this->assertSession()->elementExists('css', '.field-layout-region--content .field--name-field-test-text');
+    $this->assertSession()->elementExists('css', '.layout-region--content .field--name-field-test-text');
     $this->drupalGet('entity_test/1');
-    $this->assertSession()->elementNotExists('css', '.field-layout-region--content .field--name-field-test-text');
+    $this->assertSession()->elementNotExists('css', '.layout-region--content .field--name-field-test-text');
   }
 
   /**
    * Tests the use of field layout for entity form displays.
    */
   public function testEntityForm() {
-    // By default, the one column layout is used.
+    // By default, the one-column layout is used.
     $this->drupalGet('entity_test/manage/1/edit');
     $this->assertFieldInRegion('field_test_text[0][value]', 'content');
 
-    // The one column layout is in use.
+    // The one-column layout is in use.
     $this->drupalGet('entity_test/structure/entity_test/form-display');
     $this->assertEquals(['Content', 'Disabled'], $this->getRegionTitles());
 
     // Switch the layout to two columns.
     $this->click('#edit-field-layouts');
-    $this->getSession()->getPage()->selectFieldOption('field_layout', 'field_layout_twocol');
+    $this->getSession()->getPage()->selectFieldOption('field_layout', 'layout_twocol');
     $this->assertSession()->assertWaitOnAjaxRequest();
     $this->submitForm([], 'Save');
 
@@ -95,7 +95,7 @@ public function testEntityForm() {
     $this->drupalGet('entity_test/manage/1/edit');
     // No fields are visible, and the regions don't display when empty.
     $this->assertFieldInRegion('field_test_text[0][value]', 'left');
-    $this->assertSession()->elementExists('css', '.field-layout-region--left .field--name-field-test-text');
+    $this->assertSession()->elementExists('css', '.layout-region--left .field--name-field-test-text');
 
     // After a refresh the new regions are still there.
     $this->drupalGet('entity_test/structure/entity_test/form-display');
@@ -111,7 +111,7 @@ public function testEntityForm() {
 
     // The new layout is used.
     $this->drupalGet('entity_test/manage/1/edit');
-    $this->assertSession()->elementExists('css', '.field-layout-region--right .field--name-field-test-text');
+    $this->assertSession()->elementExists('css', '.layout-region--right .field--name-field-test-text');
     $this->assertFieldInRegion('field_test_text[0][value]', 'right');
 
     // Move the field to the right region without tabledrag.
@@ -136,13 +136,13 @@ public function testEntityForm() {
    * Tests the use of field layout for entity view displays.
    */
   public function testEntityView() {
-    // The one column layout is in use.
+    // The one-column layout is in use.
     $this->drupalGet('entity_test/structure/entity_test/display');
     $this->assertEquals(['Content', 'Disabled'], $this->getRegionTitles());
 
     // Switch the layout to two columns.
     $this->click('#edit-field-layouts');
-    $this->getSession()->getPage()->selectFieldOption('field_layout', 'field_layout_twocol');
+    $this->getSession()->getPage()->selectFieldOption('field_layout', 'layout_twocol');
     $this->assertSession()->assertWaitOnAjaxRequest();
     $this->submitForm([], 'Save');
 
@@ -151,8 +151,8 @@ public function testEntityView() {
 
     $this->drupalGet('entity_test/1');
     // No fields are visible, and the regions don't display when empty.
-    $this->assertSession()->elementNotExists('css', '.field-layout--twocol');
-    $this->assertSession()->elementNotExists('css', '.field-layout-region');
+    $this->assertSession()->elementNotExists('css', '.layout--twocol');
+    $this->assertSession()->elementNotExists('css', '.layout-region');
     $this->assertSession()->elementNotExists('css', '.field--name-field-test-text');
 
     // After a refresh the new regions are still there.
@@ -171,8 +171,8 @@ public function testEntityView() {
 
     // The new layout is used.
     $this->drupalGet('entity_test/1');
-    $this->assertSession()->elementExists('css', '.field-layout--twocol');
-    $this->assertSession()->elementExists('css', '.field-layout-region--left .field--name-field-test-text');
+    $this->assertSession()->elementExists('css', '.layout--twocol');
+    $this->assertSession()->elementExists('css', '.layout-region--left .field--name-field-test-text');
 
     // Move the field to the right region without tabledrag.
     $this->drupalGet('entity_test/structure/entity_test/display');
@@ -184,13 +184,13 @@ public function testEntityView() {
 
     // The updated region is used.
     $this->drupalGet('entity_test/1');
-    $this->assertSession()->elementExists('css', '.field-layout-region--right .field--name-field-test-text');
+    $this->assertSession()->elementExists('css', '.layout-region--right .field--name-field-test-text');
 
     // The layout is still in use without Field UI.
     $this->container->get('module_installer')->uninstall(['field_ui']);
     $this->drupalGet('entity_test/1');
-    $this->assertSession()->elementExists('css', '.field-layout--twocol');
-    $this->assertSession()->elementExists('css', '.field-layout-region--right .field--name-field-test-text');
+    $this->assertSession()->elementExists('css', '.layout--twocol');
+    $this->assertSession()->elementExists('css', '.layout-region--right .field--name-field-test-text');
   }
 
   /**
@@ -258,7 +258,7 @@ protected function getRegionTitles() {
    *   The machine name of the region.
    */
   protected function assertFieldInRegion($field_selector, $region_name) {
-    $region_element = $this->getSession()->getPage()->find('css', ".field-layout-region--$region_name");
+    $region_element = $this->getSession()->getPage()->find('css', ".layout-region--$region_name");
     $this->assertNotNull($region_element);
     $this->assertSession()->fieldExists($field_selector, $region_element);
   }
diff --git a/core/modules/field_layout/tests/src/Kernel/FieldLayoutEntityDisplayTest.php b/core/modules/field_layout/tests/src/Kernel/FieldLayoutEntityDisplayTest.php
index edfb19b..a70ecdd 100644
--- a/core/modules/field_layout/tests/src/Kernel/FieldLayoutEntityDisplayTest.php
+++ b/core/modules/field_layout/tests/src/Kernel/FieldLayoutEntityDisplayTest.php
@@ -15,7 +15,7 @@ class FieldLayoutEntityDisplayTest extends KernelTestBase {
   /**
    * {@inheritdoc}
    */
-  protected static $modules = ['layout_discovery', 'field_layout', 'entity_test', 'field_layout_test'];
+  protected static $modules = ['layout_discovery', 'field_layout', 'entity_test', 'field_layout_test', 'system'];
 
   /**
    * @covers ::preSave
@@ -40,7 +40,7 @@ public function testPreSave() {
       'dependencies' => [],
       'third_party_settings' => [
         'field_layout' => [
-          'id' => 'field_layout_onecol',
+          'id' => 'layout_onecol',
           'settings' => [],
         ],
       ],
@@ -73,7 +73,7 @@ public function testPreSave() {
       ],
       'third_party_settings' => [
         'field_layout' => [
-          'id' => 'field_layout_onecol',
+          'id' => 'layout_onecol',
           'settings' => [],
         ],
         'entity_test' => [
@@ -129,7 +129,10 @@ public function testPreSave() {
       'content' => [
         'foo' => [
           'type' => 'visible',
-          'region' => 'content',
+          'region' => 'main',
+          'weight' => -4,
+          'settings' => [],
+          'third_party_settings' => [],
         ],
       ],
       'hidden' => [
@@ -172,7 +175,43 @@ public function testPreSave() {
       'content' => [
         'foo' => [
           'type' => 'visible',
+          'region' => 'main',
+          'weight' => -4,
+          'settings' => [],
+          'third_party_settings' => [],
+        ],
+      ],
+      'hidden' => [
+        'bar' => TRUE,
+      ],
+    ];
+
+    $this->assertEntityValues($expected, $entity_display);
+
+    $expected = [
+      'langcode' => 'en',
+      'status' => TRUE,
+      'dependencies' => [
+        'module' => [
+          'entity_test',
+        ],
+      ],
+      'third_party_settings' => [
+        'entity_test' => [
+          'foo' => 'bar',
+        ],
+      ],
+      'id' => 'entity_test.entity_test.default',
+      'targetEntityType' => 'entity_test',
+      'bundle' => 'entity_test',
+      'mode' => 'default',
+      'content' => [
+        'foo' => [
+          'type' => 'visible',
           'region' => 'content',
+          'weight' => -4,
+          'settings' => [],
+          'third_party_settings' => [],
         ],
       ],
       'hidden' => [
@@ -180,6 +219,9 @@ public function testPreSave() {
       ],
     ];
 
+    $this->container->get('module_installer')->uninstall(['field_layout']);
+    $entity_storage = $this->container->get('entity_type.manager')->getStorage('entity_view_display');
+    $entity_display = $entity_storage->load('entity_test.entity_test.default');
     $this->assertEntityValues($expected, $entity_display);
   }
 
diff --git a/core/modules/field_layout/tests/src/Unit/FieldLayoutBuilderTest.php b/core/modules/field_layout/tests/src/Unit/FieldLayoutBuilderTest.php
index 4dd7204..5d881bc 100644
--- a/core/modules/field_layout/tests/src/Unit/FieldLayoutBuilderTest.php
+++ b/core/modules/field_layout/tests/src/Unit/FieldLayoutBuilderTest.php
@@ -50,8 +50,8 @@ protected function setUp() {
     parent::setUp();
 
     $this->pluginDefinition = new LayoutDefinition([
-      'library' => 'field_layout/drupal.field_layout.twocol',
-      'theme_hook' => 'field_layout__twocol',
+      'library' => 'field_layout/drupal.layout.twocol',
+      'theme_hook' => 'layout__twocol',
       'regions' => [
         'left' => [
           'label' => 'Left',
@@ -73,7 +73,7 @@ protected function setUp() {
   }
 
   /**
-   * @covers ::build
+   * @covers ::buildView
    * @covers ::getFields
    */
   public function testBuildView() {
@@ -107,8 +107,6 @@ public function testBuildView() {
       ],
     ]);
 
-    $display_context = 'view';
-
     $expected = [
       'non_configurable_field' => [
         '#markup' => 'Non-configurable',
@@ -122,21 +120,21 @@ public function testBuildView() {
         ],
         '#settings' => [],
         '#layout' => $this->pluginDefinition,
-        '#theme' => 'field_layout__twocol',
+        '#theme' => 'layout__twocol',
         '#attached' => [
           'library' => [
-            'field_layout/drupal.field_layout.twocol',
+            'field_layout/drupal.layout.twocol',
           ],
         ],
       ],
     ];
-    $this->fieldLayoutBuilder->build($build, $display->reveal(), $display_context);
+    $this->fieldLayoutBuilder->buildView($build, $display->reveal());
     $this->assertEquals($expected, $build);
     $this->assertSame($expected, $build);
   }
 
   /**
-   * @covers ::build
+   * @covers ::buildForm
    * @covers ::getFields
    */
   public function testBuildForm() {
@@ -170,8 +168,6 @@ public function testBuildForm() {
       ],
     ]);
 
-    $display_context = 'form';
-
     $expected = [
       'test1' => [
         '#markup' => 'Test1',
@@ -191,23 +187,23 @@ public function testBuildForm() {
         ],
         '#settings' => [],
         '#layout' => $this->pluginDefinition,
-        '#theme' => 'field_layout__twocol',
+        '#theme' => 'layout__twocol',
         '#attached' => [
           'library' => [
-            'field_layout/drupal.field_layout.twocol',
+            'field_layout/drupal.layout.twocol',
           ],
         ],
       ],
     ];
-    $this->fieldLayoutBuilder->build($build, $display->reveal(), $display_context);
+    $this->fieldLayoutBuilder->buildForm($build, $display->reveal());
     $this->assertEquals($expected, $build);
     $this->assertSame($expected, $build);
   }
 
   /**
-   * @covers ::build
+   * @covers ::buildForm
    */
-  public function testBuildEmpty() {
+  public function testBuildFormEmpty() {
     $definitions = [];
     $non_configurable_field_definition = $this->prophesize(FieldDefinitionInterface::class);
     $non_configurable_field_definition->isDisplayConfigurable('form')->willReturn(FALSE);
@@ -235,21 +231,19 @@ public function testBuildEmpty() {
       ],
     ]);
 
-    $display_context = 'form';
-
     $expected = [
       'non_configurable_field' => [
         '#markup' => 'Non-configurable',
       ],
     ];
-    $this->fieldLayoutBuilder->build($build, $display->reveal(), $display_context);
+    $this->fieldLayoutBuilder->buildForm($build, $display->reveal());
     $this->assertSame($expected, $build);
   }
 
   /**
-   * @covers ::build
+   * @covers ::buildForm
    */
-  public function testBuildNoLayout() {
+  public function testBuildFormNoLayout() {
     $this->entityFieldManager->getFieldDefinitions(Argument::any(), Argument::any())->shouldNotBeCalled();
 
     $build = [
@@ -263,14 +257,12 @@ public function testBuildNoLayout() {
     $display->getLayoutSettings()->willReturn([]);
     $display->getComponents()->shouldNotBeCalled();
 
-    $display_context = 'form';
-
     $expected = [
       'test1' => [
         '#markup' => 'Test1',
       ],
     ];
-    $this->fieldLayoutBuilder->build($build, $display->reveal(), $display_context);
+    $this->fieldLayoutBuilder->buildForm($build, $display->reveal());
     $this->assertSame($expected, $build);
   }