diff --git a/core/config/schema/core.entity.schema.yml b/core/config/schema/core.entity.schema.yml
index df2a2fd..de79700 100644
--- a/core/config/schema/core.entity.schema.yml
+++ b/core/config/schema/core.entity.schema.yml
@@ -84,6 +84,12 @@ core.entity_view_display.*.*.*:
       sequence:
         type: boolean
         label: 'Value'
+    layout_id:
+      type: string
+      label: 'Layout ID'
+    layout_settings:
+      type: layout_plugin.settings.[%parent.layout_id]
+      label: 'Layout settings'
 
 # Overview configuration information for form mode displays.
 core.entity_form_display.*.*.*:
@@ -135,6 +141,12 @@ core.entity_form_display.*.*.*:
       sequence:
         type: boolean
         label: 'Component'
+    layout_id:
+      type: string
+      label: 'Layout ID'
+    layout_settings:
+      type: layout_plugin.settings.[%parent.layout_id]
+      label: 'Layout settings'
 
 # Default schema for entity display field with undefined type.
 field.formatter.settings.*:
diff --git a/core/core.services.yml b/core/core.services.yml
index fc0d99f..e46d0f0 100644
--- a/core/core.services.yml
+++ b/core/core.services.yml
@@ -645,6 +645,9 @@ services:
   plugin.manager.display_variant:
     class: Drupal\Core\Display\VariantManager
     parent: default_plugin_manager
+  plugin.manager.core.layout:
+    class: Drupal\Core\Layout\LayoutPluginManager
+    arguments: ['@container.namespaces', '@cache.discovery', '@module_handler', '@theme_handler']
   plugin.manager.queue_worker:
     class: Drupal\Core\Queue\QueueWorkerManager
     parent: default_plugin_manager
diff --git a/core/includes/theme.inc b/core/includes/theme.inc
index 4cc6424..83412d9 100644
--- a/core/includes/theme.inc
+++ b/core/includes/theme.inc
@@ -1702,6 +1702,19 @@ function template_preprocess_breadcrumb(&$variables) {
 }
 
 /**
+ * Prepares variables for layout templates.
+ *
+ * @param array &$variables
+ *   An associative array containing:
+ *   - content: An associative array containing the properties of the element.
+ *     Properties used: #settings, #layout.
+ */
+function template_preprocess_layout(&$variables) {
+  $variables['settings'] = isset($variables['content']['#settings']) ? $variables['content']['#settings'] : [];
+  $variables['layout'] = isset($variables['content']['#layout']) ? $variables['content']['#layout'] : [];
+}
+
+/**
  * Callback for usort() within template_preprocess_field_multiple_value_form().
  *
  * Sorts using ['_weight']['#value']
diff --git a/core/lib/Drupal/Core/Entity/Display/EntityDisplayInterface.php b/core/lib/Drupal/Core/Entity/Display/EntityDisplayInterface.php
index 38baa15..46c9ffc 100644
--- a/core/lib/Drupal/Core/Entity/Display/EntityDisplayInterface.php
+++ b/core/lib/Drupal/Core/Entity/Display/EntityDisplayInterface.php
@@ -128,4 +128,25 @@ public function getTargetBundle();
    */
   public function setTargetBundle($bundle);
 
+  /**
+   * Gets the field's portion of the fully built entity display render array.
+   *
+   * @param string $field_name
+   *   The field name.
+   * @param array $build
+   *   The full render array.
+   *
+   * @return array
+   *   The portion of the render array corresponding to the given field name.
+   */
+  public function &getFieldFromBuild($field_name, array &$build);
+
+  /**
+   * Gets the default region.
+   *
+   * @return string
+   *   The default region for this display.
+   */
+  public function getDefaultRegion();
+
 }
diff --git a/core/modules/field_layout/src/Display/EntityDisplayWithLayoutInterface.php b/core/lib/Drupal/Core/Entity/Display/EntityDisplayWithLayoutInterface.php
similarity index 55%
rename from core/modules/field_layout/src/Display/EntityDisplayWithLayoutInterface.php
rename to core/lib/Drupal/Core/Entity/Display/EntityDisplayWithLayoutInterface.php
index 3bee65e..588b21e 100644
--- a/core/modules/field_layout/src/Display/EntityDisplayWithLayoutInterface.php
+++ b/core/lib/Drupal/Core/Entity/Display/EntityDisplayWithLayoutInterface.php
@@ -1,8 +1,7 @@
 <?php
 
-namespace Drupal\field_layout\Display;
+namespace Drupal\Core\Entity\Display;
 
-use Drupal\Core\Entity\Display\EntityDisplayInterface;
 use Drupal\Core\Layout\LayoutInterface;
 
 /**
@@ -11,14 +10,6 @@
 interface EntityDisplayWithLayoutInterface extends EntityDisplayInterface {
 
   /**
-   * Gets the default region.
-   *
-   * @return string
-   *   The default region for this display.
-   */
-  public function getDefaultRegion();
-
-  /**
    * Gets the layout plugin ID for this display.
    *
    * @return string
@@ -35,19 +26,19 @@ public function getLayoutId();
   public function getLayoutSettings();
 
   /**
-   * Sets the layout plugin ID for this display.
+   * Sets the layout for this display from a given ID and optional settings.
    *
-   * @param string|null $layout_id
-   *   Either a valid layout plugin ID, or NULL to remove the layout setting.
+   * @param string $layout_id
+   *   A layout plugin ID.
    * @param array $layout_settings
    *   (optional) An array of settings for this layout.
    *
    * @return $this
    */
-  public function setLayoutId($layout_id, array $layout_settings = []);
+  public function setLayoutFromId($layout_id, array $layout_settings = []);
 
   /**
-   * Sets the layout plugin for this display.
+   * Sets the layout for this display.
    *
    * @param \Drupal\Core\Layout\LayoutInterface $layout
    *   A layout plugin.
@@ -64,15 +55,4 @@ 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/lib/Drupal/Core/Entity/Entity/EntityFormDisplay.php b/core/lib/Drupal/Core/Entity/Entity/EntityFormDisplay.php
index faa6d0d..aa2db4b 100644
--- a/core/lib/Drupal/Core/Entity/Entity/EntityFormDisplay.php
+++ b/core/lib/Drupal/Core/Entity/Entity/EntityFormDisplay.php
@@ -30,6 +30,8 @@
  *     "mode",
  *     "content",
  *     "hidden",
+ *     "layout_id",
+ *     "layout_settings",
  *   }
  * )
  */
@@ -186,6 +188,7 @@ public function buildForm(FieldableEntityInterface $entity, array &$form, FormSt
 
     // Add a process callback so we can assign weights and hide extra fields.
     $form['#process'][] = [$this, 'processForm'];
+    $form['#process'][] = [$this, 'applyLayout'];
   }
 
   /**
@@ -213,6 +216,32 @@ public function processForm($element, FormStateInterface $form_state, $form) {
   }
 
   /**
+   * #process callback: Applies a layout to the entity form.
+   */
+  public function applyLayout($element, FormStateInterface $form_state, $form) {
+    if ($fields = $this->getFields($element)) {
+      $layout = $this->getLayout();
+      $fill = [];
+      $fill['#process'][] = '\Drupal\Core\Render\Element\RenderElement::processGroup';
+      $fill['#pre_render'][] = '\Drupal\Core\Render\Element\RenderElement::preRenderGroup';
+      $regions = array_fill_keys($layout->getPluginDefinition()->getRegionNames(), $fill);
+      foreach ($fields as $name => $field) {
+        // As this is a form, #group can be used to relocate the fields. This
+        // avoids breaking hook_form_alter() implementations by not actually
+        // moving the field in the form structure. If a #group is already set,
+        // do not overwrite it.
+        if (!isset($element[$name]['#group'])) {
+          $element[$name]['#group'] = $field['region'];
+        }
+      }
+      // Ensure this will not conflict with any existing array elements by
+      // prefixing with an underscore.
+      $element['_layout'] = $layout->build($regions);
+    }
+    return $element;
+  }
+
+  /**
    * {@inheritdoc}
    */
   public function extractFormValues(FieldableEntityInterface $entity, array &$form, FormStateInterface $form_state) {
@@ -326,7 +355,7 @@ public function getPluginCollections() {
       }
     }
 
-    return [
+    return parent::getPluginCollections() + [
       'widgets' => new EntityDisplayPluginCollection($this->pluginManager, $configurations)
     ];
   }
diff --git a/core/lib/Drupal/Core/Entity/Entity/EntityViewDisplay.php b/core/lib/Drupal/Core/Entity/Entity/EntityViewDisplay.php
index 74b15b6..38cc7ab 100644
--- a/core/lib/Drupal/Core/Entity/Entity/EntityViewDisplay.php
+++ b/core/lib/Drupal/Core/Entity/Entity/EntityViewDisplay.php
@@ -28,6 +28,8 @@
  *     "mode",
  *     "content",
  *     "hidden",
+ *     "layout_id",
+ *     "layout_settings",
  *   }
  * )
  */
@@ -278,12 +280,36 @@ public function buildMultiple(array $entities) {
         'display' => $this,
       ];
       \Drupal::moduleHandler()->alter('entity_display_build', $build_list[$id], $context);
+      $this->applyLayout($build_list[$id]);
     }
 
     return $build_list;
   }
 
   /**
+   * Applies the layout to the build.
+   *
+   * @param array $build
+   *   Render array.
+   */
+  protected function applyLayout(array &$build) {
+    if ($fields = $this->getFields($build)) {
+      $regions = [];
+      foreach ($fields as $name => $field) {
+        // Move the field from the top-level of $build into a region-specific
+        // section.
+        // @todo Ideally the array structure would remain unchanged, see
+        //   https://www.drupal.org/node/2846393.
+        $regions[$field['region']][$name] = $build[$name];
+        unset($build[$name]);
+      }
+      // Ensure this will not conflict with any existing array elements by
+      // prefixing with an underscore.
+      $build['_layout'] = $this->getLayout()->build($regions);
+    }
+  }
+
+  /**
    * {@inheritdoc}
    */
   public function getPluginCollections() {
@@ -297,7 +323,7 @@ public function getPluginCollections() {
       }
     }
 
-    return [
+    return parent::getPluginCollections() + [
       'formatters' => new EntityDisplayPluginCollection($this->pluginManager, $configurations)
     ];
   }
diff --git a/core/lib/Drupal/Core/Entity/EntityDisplayBase.php b/core/lib/Drupal/Core/Entity/EntityDisplayBase.php
index ca106b2..bdf290d 100644
--- a/core/lib/Drupal/Core/Entity/EntityDisplayBase.php
+++ b/core/lib/Drupal/Core/Entity/EntityDisplayBase.php
@@ -4,13 +4,16 @@
 
 use Drupal\Core\Config\Entity\ConfigEntityBase;
 use Drupal\Core\Config\Entity\ConfigEntityInterface;
+use Drupal\Core\Entity\Display\EntityDisplayWithLayoutInterface;
 use Drupal\Core\Field\FieldDefinitionInterface;
 use Drupal\Core\Entity\Display\EntityDisplayInterface;
+use Drupal\Core\Layout\LayoutInterface;
+use Drupal\Core\Plugin\DefaultSingleLazyPluginCollection;
 
 /**
  * Provides a common base class for entity view and form displays.
  */
-abstract class EntityDisplayBase extends ConfigEntityBase implements EntityDisplayInterface {
+abstract class EntityDisplayBase extends ConfigEntityBase implements EntityDisplayInterface, EntityDisplayWithLayoutInterface {
 
   /**
    * The 'mode' for runtime EntityDisplay objects used to render entities with
@@ -50,6 +53,13 @@
   protected $fieldDefinitions;
 
   /**
+   * An array of information about the extra fields for this display context.
+   *
+   * @var array
+   */
+  protected $extraFields;
+
+  /**
    * View or form mode to be displayed.
    *
    * @var string
@@ -79,6 +89,27 @@
   protected $hidden = [];
 
   /**
+   * The layout ID.
+   *
+   * @var string
+   */
+  protected $layout_id = 'layout_default';
+
+  /**
+   * The layout settings.
+   *
+   * @var array
+   */
+  protected $layout_settings = [];
+
+  /**
+   * The plugin collection that holds the layout plugin for this entity.
+   *
+   * @var \Drupal\Core\Plugin\DefaultSingleLazyPluginCollection
+   */
+  protected $pluginCollection;
+
+  /**
    * The original view or form mode that was requested (case of view/form modes
    * being configured to fall back to the 'default' display).
    *
@@ -156,9 +187,7 @@ protected function init() {
     if ($this->mode !== static::CUSTOM_MODE) {
       $default_region = $this->getDefaultRegion();
       // Fill in defaults for extra fields.
-      $context = $this->displayContext == 'view' ? 'display' : $this->displayContext;
-      $extra_fields = \Drupal::entityManager()->getExtraFields($this->targetEntityType, $this->bundle);
-      $extra_fields = isset($extra_fields[$context]) ? $extra_fields[$context] : [];
+      $extra_fields = $this->getExtraFields();
       foreach ($extra_fields as $name => $definition) {
         if (!isset($this->content[$name]) && !isset($this->hidden[$name])) {
           // Extra fields are visible by default unless they explicitly say so.
@@ -412,6 +441,22 @@ public function getHighestWeight() {
   }
 
   /**
+   * Gets the extra fields for this display.
+   *
+   * @return array
+   *   An array of extra field info for the entity type and bundle used by this
+   *   entity display.
+   */
+  protected function getExtraFields() {
+    if (!isset($this->extraFields)) {
+      $context = $this->displayContext == 'view' ? 'display' : $this->displayContext;
+      $extra_fields = \Drupal::service('entity_field.manager')->getExtraFields($this->targetEntityType, $this->bundle);
+      $this->extraFields = isset($extra_fields[$context]) ? $extra_fields[$context] : [];
+    }
+    return $this->extraFields;
+  }
+
+  /**
    * Gets the field definition of a field.
    */
   protected function getFieldDefinition($field_name) {
@@ -424,7 +469,7 @@ protected function getFieldDefinition($field_name) {
    */
   protected function getFieldDefinitions() {
     if (!isset($this->fieldDefinitions)) {
-      $definitions = \Drupal::entityManager()->getFieldDefinitions($this->targetEntityType, $this->bundle);
+      $definitions = \Drupal::service('entity_field.manager')->getFieldDefinitions($this->targetEntityType, $this->bundle);
       // For "official" view modes and form modes, ignore fields whose
       // definition states they should not be displayed.
       if ($this->mode !== static::CUSTOM_MODE) {
@@ -545,13 +590,112 @@ protected function getPluginRemovedDependencies(array $plugin_dependencies, arra
   }
 
   /**
+   * Gets the fields that need to be processed.
+   *
+   * @param array $build
+   *   A renderable array representing the entity content or form.
+   *
+   * @return array
+   *   An array of configurable fields present in the build.
+   */
+  protected function getFields(array $build) {
+    $components = $this->getComponents();
+
+    // Ignore any extra fields from the list of field definitions. Field
+    // definitions can have a non-configurable display, but all extra fields are
+    // always displayed.
+    $field_definitions = array_diff_key($this->getFieldDefinitions(), $this->getExtraFields());
+
+    $fields_to_exclude = array_filter($field_definitions, function (FieldDefinitionInterface $field_definition) {
+      // Remove fields with a non-configurable display.
+      return !$field_definition->isDisplayConfigurable($this->displayContext);
+    });
+    $components = array_diff_key($components, $fields_to_exclude);
+
+    // Only include fields present in the build.
+    $components = array_intersect_key($components, $build);
+
+    return $components;
+  }
+
+  /**
    * Gets the default region.
    *
    * @return string
    *   The default region for this display.
    */
-  protected function getDefaultRegion() {
-    return 'content';
+  public function getDefaultRegion() {
+    return $this->getLayout()->getPluginDefinition()->getDefaultRegion();
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function getLayoutId() {
+    return $this->layout_id;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function getLayoutSettings() {
+    return $this->layout_settings;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function setLayoutFromId($layout_id, array $layout_settings = []) {
+    $original_layout_id = $this->getLayoutId();
+    $this->layout_id = $layout_id;
+    $this->getPluginCollection()->addInstanceID($layout_id, $layout_settings);
+
+    if ($original_layout_id !== $layout_id) {
+      // @todo Devise a mechanism for mapping old regions to new ones in
+      //   https://www.drupal.org/node/2796877.
+      $layout_definition = $this->getLayout()->getPluginDefinition();
+      $new_region = $layout_definition->getDefaultRegion();
+      $layout_regions = $layout_definition->getRegions();
+      foreach ($this->getComponents() as $name => $component) {
+        if (!isset($component['region']) || !isset($layout_regions[$component['region']])) {
+          $component['region'] = $new_region;
+          $this->setComponent($name, $component);
+        }
+      }
+    }
+    return $this;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function setLayout(LayoutInterface $layout) {
+    $this->setLayoutFromId($layout->getPluginId(), $layout->getConfiguration());
+    return $this;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function getLayout() {
+    return $this->getPluginCollection()->get($this->getLayoutId());
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function &getFieldFromBuild($field_name, array &$build) {
+    $field_component = $this->getComponent($field_name);
+    if (isset($build[$field_name])) {
+      $output = &$build[$field_name];
+    }
+    elseif (isset($field_component['region']) && isset($build['_layout'][$field_component['region']][$field_name])) {
+      $output = &$build['_layout'][$field_component['region']][$field_name];
+    }
+    else {
+      $output = [];
+    }
+    return $output;
   }
 
   /**
@@ -595,4 +739,26 @@ protected function getLogger() {
     return \Drupal::logger('system');
   }
 
+  /**
+   * {@inheritdoc}
+   */
+  public function getPluginCollections() {
+    return [
+      'layout_settings' => $this->getPluginCollection(),
+    ];
+  }
+
+  /**
+   * Encapsulates the creation of the layout plugin collection.
+   *
+   * @return \Drupal\Core\Plugin\DefaultSingleLazyPluginCollection
+   *   The layout plugin collection.
+   */
+  protected function getPluginCollection() {
+    if (!$this->pluginCollection) {
+      $this->pluginCollection = new DefaultSingleLazyPluginCollection(\Drupal::service('plugin.manager.core.layout'), $this->getLayoutId(), $this->getLayoutSettings());
+    }
+    return $this->pluginCollection;
+  }
+
 }
diff --git a/core/lib/Drupal/Core/Entity/EntityViewBuilder.php b/core/lib/Drupal/Core/Entity/EntityViewBuilder.php
index 2c3340e..778c152 100644
--- a/core/lib/Drupal/Core/Entity/EntityViewBuilder.php
+++ b/core/lib/Drupal/Core/Entity/EntityViewBuilder.php
@@ -399,13 +399,8 @@ public function viewField(FieldItemListInterface $items, $display_options = [])
     $field_name = $items->getFieldDefinition()->getName();
     $display = $this->getSingleFieldDisplay($entity, $field_name, $display_options);
 
-    $output = [];
     $build = $display->build($entity);
-    if (isset($build[$field_name])) {
-      $output = $build[$field_name];
-    }
-
-    return $output;
+    return $display->getFieldFromBuild($field_name, $build);
   }
 
   /**
@@ -465,11 +460,14 @@ protected function getSingleFieldDisplay($entity, $field_name, $display_options)
       $bundle = $entity->bundle();
       $key = $entity_type_id . ':' . $bundle . ':' . $field_name . ':' . Crypt::hashBase64(serialize($display_options));
       if (!isset($this->singleFieldDisplays[$key])) {
-        $this->singleFieldDisplays[$key] = EntityViewDisplay::create([
+        $display = EntityViewDisplay::create([
           'targetEntityType' => $entity_type_id,
           'bundle' => $bundle,
           'status' => TRUE,
-        ])->setComponent($field_name, $display_options);
+        ]);
+        $display_options += ['region' => $display->getDefaultRegion()];
+        $display->setComponent($field_name, $display_options);
+        $this->singleFieldDisplays[$key] = $display;
       }
       $display = $this->singleFieldDisplays[$key];
     }
diff --git a/core/lib/Drupal/Core/Layout/Annotation/Layout.php b/core/lib/Drupal/Core/Layout/Annotation/Layout.php
index 1cb5ff0..0b3c303 100644
--- a/core/lib/Drupal/Core/Layout/Annotation/Layout.php
+++ b/core/lib/Drupal/Core/Layout/Annotation/Layout.php
@@ -14,11 +14,6 @@
  *
  * Plugin namespace: Plugin\Layout
  *
- * @internal
- *   The layout system is currently experimental and should only be leveraged by
- *   experimental modules and development releases of contributed modules.
- *   See https://www.drupal.org/core/experimental for more information.
- *
  * @see \Drupal\Core\Layout\LayoutInterface
  * @see \Drupal\Core\Layout\LayoutDefault
  * @see \Drupal\Core\Layout\LayoutPluginManager
@@ -72,9 +67,9 @@ class Layout extends Plugin {
   /**
    * The template file to render this layout (relative to the 'path' given).
    *
-   * If specified, then the layout_discovery module will register the template
-   * with hook_theme() and the module or theme registering this layout does not
-   * need to do it.
+   * If specified, then the system module will register the template with
+   * hook_theme() and the module or theme registering this layout does not need
+   * to do it.
    *
    * @var string optional
    *
diff --git a/core/lib/Drupal/Core/Layout/LayoutDefault.php b/core/lib/Drupal/Core/Layout/LayoutDefault.php
index 22edb85..6e53d00 100644
--- a/core/lib/Drupal/Core/Layout/LayoutDefault.php
+++ b/core/lib/Drupal/Core/Layout/LayoutDefault.php
@@ -7,11 +7,6 @@
 
 /**
  * Provides a default class for Layout plugins.
- *
- * @internal
- *   The layout system is currently experimental and should only be leveraged by
- *   experimental modules and development releases of contributed modules.
- *   See https://www.drupal.org/core/experimental for more information.
  */
 class LayoutDefault extends PluginBase implements LayoutInterface {
 
diff --git a/core/lib/Drupal/Core/Layout/LayoutDefinition.php b/core/lib/Drupal/Core/Layout/LayoutDefinition.php
index afbce7e..686cf81 100644
--- a/core/lib/Drupal/Core/Layout/LayoutDefinition.php
+++ b/core/lib/Drupal/Core/Layout/LayoutDefinition.php
@@ -10,11 +10,6 @@
 
 /**
  * Provides an implementation of a layout definition and its metadata.
- *
- * @internal
- *   The layout system is currently experimental and should only be leveraged by
- *   experimental modules and development releases of contributed modules.
- *   See https://www.drupal.org/core/experimental for more information.
  */
 class LayoutDefinition extends PluginDefinition implements PluginDefinitionInterface, DerivablePluginDefinitionInterface, DependentPluginDefinitionInterface {
 
diff --git a/core/lib/Drupal/Core/Layout/LayoutInterface.php b/core/lib/Drupal/Core/Layout/LayoutInterface.php
index bb60df0..32ee74d 100644
--- a/core/lib/Drupal/Core/Layout/LayoutInterface.php
+++ b/core/lib/Drupal/Core/Layout/LayoutInterface.php
@@ -8,11 +8,6 @@
 
 /**
  * Provides an interface for static Layout plugins.
- *
- * @internal
- *   The layout system is currently experimental and should only be leveraged by
- *   experimental modules and development releases of contributed modules.
- *   See https://www.drupal.org/core/experimental for more information.
  */
 interface LayoutInterface extends PluginInspectionInterface, DerivativeInspectionInterface, ConfigurablePluginInterface {
 
diff --git a/core/lib/Drupal/Core/Layout/LayoutPluginManager.php b/core/lib/Drupal/Core/Layout/LayoutPluginManager.php
index 0a28785..179d1ed 100644
--- a/core/lib/Drupal/Core/Layout/LayoutPluginManager.php
+++ b/core/lib/Drupal/Core/Layout/LayoutPluginManager.php
@@ -15,11 +15,6 @@
 
 /**
  * Provides a plugin manager for layouts.
- *
- * @internal
- *   The layout system is currently experimental and should only be leveraged by
- *   experimental modules and development releases of contributed modules.
- *   See https://www.drupal.org/core/experimental for more information.
  */
 class LayoutPluginManager extends DefaultPluginManager implements LayoutPluginManagerInterface {
 
diff --git a/core/lib/Drupal/Core/Layout/LayoutPluginManagerInterface.php b/core/lib/Drupal/Core/Layout/LayoutPluginManagerInterface.php
index df15be0..c0e606d 100644
--- a/core/lib/Drupal/Core/Layout/LayoutPluginManagerInterface.php
+++ b/core/lib/Drupal/Core/Layout/LayoutPluginManagerInterface.php
@@ -6,11 +6,6 @@
 
 /**
  * Provides the interface for a plugin manager of layouts.
- *
- * @internal
- *   The layout system is currently experimental and should only be leveraged by
- *   experimental modules and development releases of contributed modules.
- *   See https://www.drupal.org/core/experimental for more information.
  */
 interface LayoutPluginManagerInterface extends CategorizingPluginManagerInterface {
 
diff --git a/core/lib/Drupal/Core/Layout/Plugin/Layout/DefaultLayout.php b/core/lib/Drupal/Core/Layout/Plugin/Layout/DefaultLayout.php
new file mode 100644
index 0000000..2d65047
--- /dev/null
+++ b/core/lib/Drupal/Core/Layout/Plugin/Layout/DefaultLayout.php
@@ -0,0 +1,33 @@
+<?php
+
+namespace Drupal\Core\Layout\Plugin\Layout;
+
+use Drupal\Core\Layout\LayoutDefault;
+
+/**
+ * Provides a default layout with no markup.
+ *
+ * @Layout(
+ *   id = "layout_default",
+ *   label = @Translation("Default"),
+ *   category = @Translation("Columns: 1"),
+ *   regions = {
+ *     "content" = {
+ *       "label" = @Translation("Content")
+ *     },
+ *   },
+ * )
+ */
+class DefaultLayout extends LayoutDefault {
+
+  /**
+   * {@inheritdoc}
+   */
+  public function build(array $regions) {
+    $build = parent::build($regions);
+    // Remove the theme hook so no additional markup is added.
+    unset($build['#theme']);
+    return $build;
+  }
+
+}
diff --git a/core/modules/aggregator/config/install/core.entity_view_display.aggregator_feed.aggregator_feed.default.yml b/core/modules/aggregator/config/install/core.entity_view_display.aggregator_feed.aggregator_feed.default.yml
index e0232cf..f982504 100644
--- a/core/modules/aggregator/config/install/core.entity_view_display.aggregator_feed.aggregator_feed.default.yml
+++ b/core/modules/aggregator/config/install/core.entity_view_display.aggregator_feed.aggregator_feed.default.yml
@@ -36,3 +36,5 @@ content:
     label: inline
 hidden:
   more_link: true
+layout_id: layout_default
+layout_settings: {  }
diff --git a/core/modules/aggregator/config/install/core.entity_view_display.aggregator_feed.aggregator_feed.summary.yml b/core/modules/aggregator/config/install/core.entity_view_display.aggregator_feed.aggregator_feed.summary.yml
index 5e5e468..917d410 100644
--- a/core/modules/aggregator/config/install/core.entity_view_display.aggregator_feed.aggregator_feed.summary.yml
+++ b/core/modules/aggregator/config/install/core.entity_view_display.aggregator_feed.aggregator_feed.summary.yml
@@ -22,3 +22,5 @@ hidden:
   feed_icon: true
   image: true
   link: true
+layout_id: layout_default
+layout_settings: {  }
diff --git a/core/modules/aggregator/config/install/core.entity_view_display.aggregator_item.aggregator_item.summary.yml b/core/modules/aggregator/config/install/core.entity_view_display.aggregator_item.aggregator_item.summary.yml
index 8e29395..5aa077b 100644
--- a/core/modules/aggregator/config/install/core.entity_view_display.aggregator_item.aggregator_item.summary.yml
+++ b/core/modules/aggregator/config/install/core.entity_view_display.aggregator_item.aggregator_item.summary.yml
@@ -18,3 +18,5 @@ hidden:
   description: true
   feed: true
   link: true
+layout_id: layout_default
+layout_settings: {  }
diff --git a/core/modules/book/config/optional/core.entity_form_display.node.book.default.yml b/core/modules/book/config/optional/core.entity_form_display.node.book.default.yml
index 58aba45..213d1f3 100644
--- a/core/modules/book/config/optional/core.entity_form_display.node.book.default.yml
+++ b/core/modules/book/config/optional/core.entity_form_display.node.book.default.yml
@@ -58,3 +58,5 @@ content:
       placeholder: ''
     third_party_settings: {  }
 hidden: {  }
+layout_id: layout_default
+layout_settings: {  }
diff --git a/core/modules/book/config/optional/core.entity_view_display.node.book.default.yml b/core/modules/book/config/optional/core.entity_view_display.node.book.default.yml
index d6ef64d..caf15c9 100644
--- a/core/modules/book/config/optional/core.entity_view_display.node.book.default.yml
+++ b/core/modules/book/config/optional/core.entity_view_display.node.book.default.yml
@@ -23,3 +23,5 @@ content:
     weight: 101
     region: content
 hidden: {  }
+layout_id: layout_default
+layout_settings: {  }
diff --git a/core/modules/book/config/optional/core.entity_view_display.node.book.teaser.yml b/core/modules/book/config/optional/core.entity_view_display.node.book.teaser.yml
index 77a62c3..7d48aaa 100644
--- a/core/modules/book/config/optional/core.entity_view_display.node.book.teaser.yml
+++ b/core/modules/book/config/optional/core.entity_view_display.node.book.teaser.yml
@@ -25,3 +25,5 @@ content:
     weight: 101
     region: content
 hidden: {  }
+layout_id: layout_default
+layout_settings: {  }
diff --git a/core/modules/field/tests/src/Kernel/FieldAttachOtherTest.php b/core/modules/field/tests/src/Kernel/FieldAttachOtherTest.php
index 05fdfae..e6d3680 100644
--- a/core/modules/field/tests/src/Kernel/FieldAttachOtherTest.php
+++ b/core/modules/field/tests/src/Kernel/FieldAttachOtherTest.php
@@ -2,6 +2,7 @@
 
 namespace Drupal\Tests\field\Kernel;
 
+use Drupal\Core\Entity\Entity\EntityViewMode;
 use Drupal\Core\Form\FormState;
 use Drupal\entity_test\Entity\EntityTest;
 
@@ -18,6 +19,14 @@ protected function setUp() {
     $this->container->get('router.builder')->rebuild();
     $this->installEntitySchema('entity_test_rev');
     $this->createFieldWithStorage();
+
+    EntityViewMode::create([
+      'id' => 'entity_test.full',
+      'targetEntityType' => 'entity_test',
+      'status' => TRUE,
+      'enabled' => TRUE,
+      'label' => 'Full',
+    ])->save();
   }
 
   /**
@@ -60,6 +69,7 @@ public function testEntityDisplayBuild() {
       ],
     ];
     $display->setComponent($this->fieldTestData->field_name_2, $display_options_2);
+    $display->save();
 
     // View all fields.
     $content = $display->build($entity);
@@ -77,6 +87,7 @@ public function testEntityDisplayBuild() {
     $entity = clone($entity_init);
     $display_options['label'] = 'hidden';
     $display->setComponent($this->fieldTestData->field_name, $display_options);
+    $display->save();
     $content = $display->build($entity);
     $this->render($content);
     $this->assertNoRaw($this->fieldTestData->field->getLabel(), "Hidden label: label is not displayed.");
@@ -84,6 +95,7 @@ public function testEntityDisplayBuild() {
     // Field hidden.
     $entity = clone($entity_init);
     $display->removeComponent($this->fieldTestData->field_name);
+    $display->save();
     $content = $display->build($entity);
     $this->render($content);
     $this->assertNoRaw($this->fieldTestData->field->getLabel(), "Hidden field: label is not displayed.");
@@ -101,6 +113,7 @@ public function testEntityDisplayBuild() {
         'test_formatter_setting_multiple' => $formatter_setting,
       ],
     ]);
+    $display->save();
     $content = $display->build($entity);
     $this->render($content);
     $expected_output = $formatter_setting;
@@ -119,6 +132,7 @@ public function testEntityDisplayBuild() {
         'test_formatter_setting_additional' => $formatter_setting,
       ],
     ]);
+    $display->save();
     $content = $display->build($entity);
     $this->render($content);
     foreach ($values as $delta => $value) {
@@ -139,6 +153,7 @@ public function testEntityDisplayViewMultiple() {
       ->setComponent($this->fieldTestData->field_name, [
         'type' => 'field_test_with_prepare_view',
       ]);
+    $display->save();
 
     // Create two entities.
     $entity1 = EntityTest::create(['id' => 1, 'type' => 'entity_test']);
diff --git a/core/modules/field_layout/config/schema/field_layout.schema.yml b/core/modules/field_layout/config/schema/field_layout.schema.yml
deleted file mode 100644
index 185fb4e..0000000
--- a/core/modules/field_layout/config/schema/field_layout.schema.yml
+++ /dev/null
@@ -1,16 +0,0 @@
-core.entity_view_display.*.*.*.third_party.field_layout:
-  type: field_layout.third_party_settings
-
-core.entity_form_display.*.*.*.third_party.field_layout:
-  type: field_layout.third_party_settings
-
-field_layout.third_party_settings:
-  type: mapping
-  label: 'Per-view-mode field layout settings'
-  mapping:
-    id:
-      type: string
-      label: 'Layout ID'
-    settings:
-      type: layout_plugin.settings.[%parent.id]
-      label: 'Layout settings'
diff --git a/core/modules/field_layout/field_layout.info.yml b/core/modules/field_layout/field_layout.info.yml
index 237f18d..62f225a 100644
--- a/core/modules/field_layout/field_layout.info.yml
+++ b/core/modules/field_layout/field_layout.info.yml
@@ -4,5 +4,3 @@ description: 'Adds layout capabilities to the Field UI.'
 package: Core (Experimental)
 version: VERSION
 core: 8.x
-dependencies:
-  - layout_discovery
diff --git a/core/modules/field_layout/field_layout.install b/core/modules/field_layout/field_layout.install
deleted file mode 100644
index 5956bf1..0000000
--- a/core/modules/field_layout/field_layout.install
+++ /dev/null
@@ -1,42 +0,0 @@
-<?php
-
-/**
- * @file
- * Contains install and update functions for Field Layout.
- */
-
-use Drupal\Core\Cache\Cache;
-use Drupal\Core\Entity\Entity\EntityFormDisplay;
-use Drupal\Core\Entity\Entity\EntityViewDisplay;
-use Drupal\field_layout\Display\EntityDisplayWithLayoutInterface;
-
-/**
- * Implements hook_install().
- */
-function field_layout_install() {
-  // 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());
-
-  // 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.module b/core/modules/field_layout/field_layout.module
index 5a5fa11..1607a8a 100644
--- a/core/modules/field_layout/field_layout.module
+++ b/core/modules/field_layout/field_layout.module
@@ -5,15 +5,7 @@
  * Provides hook implementations for Field Layout.
  */
 
-use Drupal\Core\Entity\ContentEntityFormInterface;
-use Drupal\Core\Entity\Display\EntityViewDisplayInterface;
-use Drupal\Core\Entity\EntityInterface;
-use Drupal\Core\Form\FormStateInterface;
 use Drupal\Core\Routing\RouteMatchInterface;
-use Drupal\field_layout\Display\EntityDisplayWithLayoutInterface;
-use Drupal\field_layout\Entity\FieldLayoutEntityFormDisplay;
-use Drupal\field_layout\Entity\FieldLayoutEntityViewDisplay;
-use Drupal\field_layout\FieldLayoutBuilder;
 use Drupal\field_layout\Form\FieldLayoutEntityFormDisplayEditForm;
 use Drupal\field_layout\Form\FieldLayoutEntityViewDisplayEditForm;
 
@@ -35,35 +27,9 @@ function field_layout_help($route_name, RouteMatchInterface $route_match) {
  */
 function field_layout_entity_type_alter(array &$entity_types) {
   /** @var $entity_types \Drupal\Core\Entity\EntityTypeInterface[] */
-  $entity_types['entity_view_display']->setClass(FieldLayoutEntityViewDisplay::class);
-  $entity_types['entity_form_display']->setClass(FieldLayoutEntityFormDisplay::class);
-
   // The form classes are only needed when Field UI is installed.
   if (\Drupal::moduleHandler()->moduleExists('field_ui')) {
     $entity_types['entity_view_display']->setFormClass('edit', FieldLayoutEntityViewDisplayEditForm::class);
     $entity_types['entity_form_display']->setFormClass('edit', FieldLayoutEntityFormDisplayEditForm::class);
   }
 }
-
-/**
- * Implements hook_entity_view_alter().
- */
-function field_layout_entity_view_alter(array &$build, EntityInterface $entity, EntityViewDisplayInterface $display) {
-  if ($display instanceof EntityDisplayWithLayoutInterface) {
-    \Drupal::classResolver()->getInstanceFromDefinition(FieldLayoutBuilder::class)
-      ->buildView($build, $display);
-  }
-}
-
-/**
- * Implements hook_form_alter().
- */
-function field_layout_form_alter(&$form, FormStateInterface $form_state, $form_id) {
-  $form_object = $form_state->getFormObject();
-  if ($form_object instanceof ContentEntityFormInterface && $display = $form_object->getFormDisplay($form_state)) {
-    if ($display instanceof EntityDisplayWithLayoutInterface) {
-      \Drupal::classResolver()->getInstanceFromDefinition(FieldLayoutBuilder::class)
-        ->buildForm($form, $display);
-    }
-  }
-}
diff --git a/core/modules/field_layout/src/Entity/FieldLayoutEntityDisplayTrait.php b/core/modules/field_layout/src/Entity/FieldLayoutEntityDisplayTrait.php
deleted file mode 100644
index 59377be..0000000
--- a/core/modules/field_layout/src/Entity/FieldLayoutEntityDisplayTrait.php
+++ /dev/null
@@ -1,153 +0,0 @@
-<?php
-
-namespace Drupal\field_layout\Entity;
-
-use Drupal\Core\Entity\EntityStorageInterface;
-use Drupal\Core\Layout\LayoutInterface;
-
-/**
- * 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 {
-
-  /**
-   * Gets a layout definition.
-   *
-   * @param string $layout_id
-   *   The layout ID.
-   *
-   * @return \Drupal\Core\Layout\LayoutDefinition
-   *   The layout definition.
-   */
-  protected function getLayoutDefinition($layout_id) {
-    return \Drupal::service('plugin.manager.core.layout')->getDefinition($layout_id);
-  }
-
-  /**
-   * Implements \Drupal\field_layout\Display\EntityDisplayWithLayoutInterface::getLayoutId().
-   */
-  public function getLayoutId() {
-    return $this->getThirdPartySetting('field_layout', 'id');
-  }
-
-  /**
-   * Implements \Drupal\field_layout\Display\EntityDisplayWithLayoutInterface::getLayoutSettings().
-   */
-  public function getLayoutSettings() {
-    return $this->getThirdPartySetting('field_layout', 'settings', []);
-  }
-
-  /**
-   * Implements \Drupal\field_layout\Display\EntityDisplayWithLayoutInterface::setLayoutId().
-   */
-  public function setLayoutId($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.
-      $layout_definition = $this->getLayoutDefinition($layout_id);
-      $new_region = $layout_definition->getDefaultRegion();
-      $layout_regions = $layout_definition->getRegions();
-      foreach ($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);
-    // Instantiate the plugin and consult it for the updated plugin
-    // configuration. Once layouts are no longer stored as third party settings,
-    // this will be handled by the code in
-    // \Drupal\Core\Config\Entity\ConfigEntityBase::set() that handles
-    // \Drupal\Core\Entity\EntityWithPluginCollectionInterface.
-    $layout_settings = $this->doGetLayout($layout_id, $layout_settings)->getConfiguration();
-    $this->setThirdPartySetting('field_layout', 'settings', $layout_settings);
-    return $this;
-  }
-
-  /**
-   * Implements \Drupal\field_layout\Display\EntityDisplayWithLayoutInterface::setLayout().
-   */
-  public function setLayout(LayoutInterface $layout) {
-    $this->setLayoutId($layout->getPluginId(), $layout->getConfiguration());
-    return $this;
-  }
-
-  /**
-   * Implements \Drupal\field_layout\Display\EntityDisplayWithLayoutInterface::getLayout().
-   */
-  public function getLayout() {
-    return $this->doGetLayout($this->getLayoutId(), $this->getLayoutSettings());
-  }
-
-  /**
-   * Gets the layout plugin.
-   *
-   * @param string $layout_id
-   *   A layout plugin ID.
-   * @param array $layout_settings
-   *   An array of settings.
-   *
-   * @return \Drupal\Core\Layout\LayoutInterface
-   *   The layout plugin.
-   */
-  protected function doGetLayout($layout_id, array $layout_settings) {
-    return \Drupal::service('plugin.manager.core.layout')->createInstance($layout_id, $layout_settings);
-  }
-
-  /**
-   * Overrides \Drupal\Core\Entity\EntityDisplayBase::init().
-   */
-  protected function init() {
-    $this->ensureLayout();
-    parent::init();
-  }
-
-  /**
-   * Overrides \Drupal\Core\Entity\EntityDisplayBase::preSave().
-   */
-  public function preSave(EntityStorageInterface $storage) {
-    parent::preSave($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.
-    if ($this->getLayoutId()) {
-      $this->setLayout($this->getLayout());
-    }
-  }
-
-  /**
-   * {@inheritdoc}
-   */
-  public function ensureLayout($default_layout_id = 'layout_onecol') {
-    if (!$this->getLayoutId()) {
-      $this->setLayoutId($default_layout_id);
-    }
-
-    return $this;
-  }
-
-  /**
-   * Overrides \Drupal\Core\Entity\EntityDisplayBase::calculateDependencies().
-   *
-   * Ensure the plugin dependencies are included. Once layouts are no longer
-   * stored as third party settings, this will be handled by the code in
-   * \Drupal\Core\Config\Entity\ConfigEntityBase::calculateDependencies() that
-   * handles \Drupal\Core\Entity\EntityWithPluginCollectionInterface.
-   */
-  public function calculateDependencies() {
-    parent::calculateDependencies();
-
-    // This can be called during uninstallation, so check for a valid ID first.
-    if ($this->getLayoutId()) {
-      $this->calculatePluginDependencies($this->getLayout());
-    }
-  }
-
-}
diff --git a/core/modules/field_layout/src/Entity/FieldLayoutEntityFormDisplay.php b/core/modules/field_layout/src/Entity/FieldLayoutEntityFormDisplay.php
deleted file mode 100644
index c58938e..0000000
--- a/core/modules/field_layout/src/Entity/FieldLayoutEntityFormDisplay.php
+++ /dev/null
@@ -1,24 +0,0 @@
-<?php
-
-namespace Drupal\field_layout\Entity;
-
-use Drupal\Core\Entity\Entity\EntityFormDisplay;
-use Drupal\field_layout\Display\EntityDisplayWithLayoutInterface;
-
-/**
- * Provides an entity form display entity that has a layout.
- */
-class FieldLayoutEntityFormDisplay extends EntityFormDisplay implements EntityDisplayWithLayoutInterface {
-
-  use FieldLayoutEntityDisplayTrait;
-
-  /**
-   * {@inheritdoc}
-   */
-  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
deleted file mode 100644
index 4f0c274..0000000
--- a/core/modules/field_layout/src/Entity/FieldLayoutEntityViewDisplay.php
+++ /dev/null
@@ -1,24 +0,0 @@
-<?php
-
-namespace Drupal\field_layout\Entity;
-
-use Drupal\Core\Entity\Entity\EntityViewDisplay;
-use Drupal\field_layout\Display\EntityDisplayWithLayoutInterface;
-
-/**
- * Provides an entity view display entity that has a layout.
- */
-class FieldLayoutEntityViewDisplay extends EntityViewDisplay implements EntityDisplayWithLayoutInterface {
-
-  use FieldLayoutEntityDisplayTrait;
-
-  /**
-   * {@inheritdoc}
-   */
-  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
deleted file mode 100644
index 8ef5d04..0000000
--- a/core/modules/field_layout/src/FieldLayoutBuilder.php
+++ /dev/null
@@ -1,153 +0,0 @@
-<?php
-
-namespace Drupal\field_layout;
-
-use Drupal\Core\DependencyInjection\ContainerInjectionInterface;
-use Drupal\Core\Entity\EntityFieldManagerInterface;
-use Drupal\Core\Field\FieldDefinitionInterface;
-use Drupal\field_layout\Display\EntityDisplayWithLayoutInterface;
-use Drupal\Core\Layout\LayoutPluginManagerInterface;
-use Symfony\Component\DependencyInjection\ContainerInterface;
-
-/**
- * Builds a field layout.
- */
-class FieldLayoutBuilder implements ContainerInjectionInterface {
-
-  /**
-   * The layout plugin manager.
-   *
-   * @var \Drupal\Core\Layout\LayoutPluginManagerInterface
-   */
-  protected $layoutPluginManager;
-
-  /**
-   * The entity field manager.
-   *
-   * @var \Drupal\Core\Entity\EntityFieldManagerInterface
-   */
-  protected $entityFieldManager;
-
-  /**
-   * Constructs a new FieldLayoutBuilder.
-   *
-   * @param \Drupal\Core\Layout\LayoutPluginManagerInterface $layout_plugin_manager
-   *   The layout plugin manager.
-   * @param \Drupal\Core\Entity\EntityFieldManagerInterface $entity_field_manager
-   *   The entity field manager.
-   */
-  public function __construct(LayoutPluginManagerInterface $layout_plugin_manager, EntityFieldManagerInterface $entity_field_manager) {
-    $this->layoutPluginManager = $layout_plugin_manager;
-    $this->entityFieldManager = $entity_field_manager;
-  }
-
-  /**
-   * {@inheritdoc}
-   */
-  public static function create(ContainerInterface $container) {
-    return new static(
-      $container->get('plugin.manager.core.layout'),
-      $container->get('entity_field.manager')
-    );
-  }
-
-  /**
-   * Applies the layout to an entity build.
-   *
-   * @param array $build
-   *   A renderable array representing the entity content or form.
-   * @param \Drupal\field_layout\Display\EntityDisplayWithLayoutInterface $display
-   *   The entity display holding the display options configured for the entity
-   *   components.
-   */
-  public function buildView(array &$build, EntityDisplayWithLayoutInterface $display) {
-    $layout_definition = $this->layoutPluginManager->getDefinition($display->getLayoutId(), FALSE);
-    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.
-        // @todo Ideally the array structure would remain unchanged, see
-        //   https://www.drupal.org/node/2846393.
-        $regions[$field['region']][$name] = $build[$name];
-        unset($build[$name]);
-      }
-      // Ensure this will not conflict with any existing array elements by
-      // prefixing with an underscore.
-      $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')) {
-      $fill = [];
-      $fill['#process'][] = '\Drupal\Core\Render\Element\RenderElement::processGroup';
-      $fill['#pre_render'][] = '\Drupal\Core\Render\Element\RenderElement::preRenderGroup';
-      // Add the regions to the $build in the correct order.
-      $regions = array_fill_keys($layout_definition->getRegionNames(), $fill);
-
-      foreach ($fields as $name => $field) {
-        // As this is a form, #group can be used to relocate the fields. This
-        // avoids breaking hook_form_alter() implementations by not actually
-        // moving the field in the form structure. If a #group is already set,
-        // do not overwrite it.
-        if (!isset($build[$name]['#group'])) {
-          $build[$name]['#group'] = $field['region'];
-        }
-      }
-      // Ensure this will not conflict with any existing array elements by
-      // prefixing with an underscore.
-      $build['_field_layout'] = $display->getLayout()->build($regions);
-    }
-  }
-
-  /**
-   * Gets the fields that need to be processed.
-   *
-   * @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.
-   * @param string $display_context
-   *   The display context, either 'form' or 'view'.
-   *
-   * @return array
-   *   An array of configurable fields present in the build.
-   */
-  protected function getFields(array $build, EntityDisplayWithLayoutInterface $display, $display_context) {
-    $components = $display->getComponents();
-
-    // Ignore any extra fields from the list of field definitions. Field
-    // definitions can have a non-configurable display, but all extra fields are
-    // always displayed.
-    $field_definitions = array_diff_key(
-      $this->entityFieldManager->getFieldDefinitions($display->getTargetEntityTypeId(), $display->getTargetBundle()),
-      $this->entityFieldManager->getExtraFields($display->getTargetEntityTypeId(), $display->getTargetBundle())
-    );
-
-    $fields_to_exclude = array_filter($field_definitions, function (FieldDefinitionInterface $field_definition) use ($display_context) {
-      // Remove fields with a non-configurable display.
-      return !$field_definition->isDisplayConfigurable($display_context);
-    });
-    $components = array_diff_key($components, $fields_to_exclude);
-
-    // Only include fields present in the build.
-    $components = array_intersect_key($components, $build);
-
-    return $components;
-  }
-
-}
diff --git a/core/modules/field_layout/src/Form/FieldLayoutEntityDisplayFormTrait.php b/core/modules/field_layout/src/Form/FieldLayoutEntityDisplayFormTrait.php
index 043e5c7..1616861 100644
--- a/core/modules/field_layout/src/Form/FieldLayoutEntityDisplayFormTrait.php
+++ b/core/modules/field_layout/src/Form/FieldLayoutEntityDisplayFormTrait.php
@@ -5,7 +5,7 @@
 use Drupal\Core\Form\FormStateInterface;
 use Drupal\Core\Form\SubformState;
 use Drupal\Core\Plugin\PluginFormInterface;
-use Drupal\field_layout\Display\EntityDisplayWithLayoutInterface;
+use Drupal\Core\Entity\Display\EntityDisplayWithLayoutInterface;
 
 /**
  * Provides shared code for entity display forms.
@@ -99,7 +99,7 @@ public function form(array $form, FormStateInterface $form_state) {
   /**
    * Gets the layout plugin for the currently selected field layout.
    *
-   * @param \Drupal\field_layout\Display\EntityDisplayWithLayoutInterface $entity
+   * @param \Drupal\Core\Entity\Display\EntityDisplayWithLayoutInterface $entity
    *   The current form entity.
    * @param \Drupal\Core\Form\FormStateInterface $form_state
    *   The current state of the form.
@@ -169,7 +169,7 @@ public function submitForm(array &$form, FormStateInterface $form_state) {
   /**
    * Gets the form entity.
    *
-   * @return \Drupal\field_layout\Display\EntityDisplayWithLayoutInterface
+   * @return \Drupal\Core\Entity\Display\EntityDisplayWithLayoutInterface
    *   The current form entity.
    */
   abstract public function getEntity();
diff --git a/core/modules/field_layout/tests/modules/field_layout_test/field_layout_test.module b/core/modules/field_layout/tests/modules/field_layout_test/field_layout_test.module
index 6905c3d..f4c5864 100644
--- a/core/modules/field_layout/tests/modules/field_layout_test/field_layout_test.module
+++ b/core/modules/field_layout/tests/modules/field_layout_test/field_layout_test.module
@@ -10,7 +10,7 @@
  */
 function field_layout_test_layout_alter(&$definitions) {
   /** @var \Drupal\Core\Layout\LayoutDefinition[] $definitions */
-  if (\Drupal::state()->get('field_layout_test.alter_regions') && isset($definitions['layout_onecol'])) {
-    $definitions['layout_onecol']->setRegions(['foo' => ['label' => 'Foo']]);
+  if (\Drupal::state()->get('field_layout_test.alter_regions') && isset($definitions['layout_default'])) {
+    $definitions['layout_default']->setRegions(['foo' => ['label' => 'Foo']]);
   }
 }
diff --git a/core/modules/field_layout/tests/src/Functional/FieldLayoutTest.php b/core/modules/field_layout/tests/src/Functional/FieldLayoutTest.php
index 058e6c3..e290bc7 100644
--- a/core/modules/field_layout/tests/src/Functional/FieldLayoutTest.php
+++ b/core/modules/field_layout/tests/src/Functional/FieldLayoutTest.php
@@ -44,20 +44,6 @@ protected function setUp() {
   }
 
   /**
-   * Tests an entity type that has fields shown by default.
-   */
-  public function testNodeView() {
-    // By default, the one-column layout is used.
-    $this->drupalGet('node/1');
-    $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());
-    $this->assertSession()->optionExists('fields[body][region]', 'content');
-  }
-
-  /**
    * Tests that changes to the regions still leave the fields visible.
    */
   public function testRegionChanges() {
diff --git a/core/modules/field_layout/tests/src/FunctionalJavascript/FieldLayoutTest.php b/core/modules/field_layout/tests/src/FunctionalJavascript/FieldLayoutTest.php
index 8ddbeaf..c3287dd 100644
--- a/core/modules/field_layout/tests/src/FunctionalJavascript/FieldLayoutTest.php
+++ b/core/modules/field_layout/tests/src/FunctionalJavascript/FieldLayoutTest.php
@@ -15,7 +15,7 @@ class FieldLayoutTest extends JavascriptTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['field_layout', 'field_ui', 'field_layout_test', 'layout_test'];
+  public static $modules = ['field_layout', 'field_ui', 'field_layout_test', 'layout_test', 'layout_discovery'];
 
   /**
    * {@inheritdoc}
@@ -47,9 +47,22 @@ protected function setUp() {
   public function testEntityViewModes() {
     // By default, the field is not visible.
     $this->drupalGet('entity_test/1/test');
-    $this->assertSession()->elementNotExists('css', '.layout__region--content .field--name-field-test-text');
+    $this->assertSession()->elementNotExists('css', '.field--name-field-test-text');
     $this->drupalGet('entity_test/1');
-    $this->assertSession()->elementNotExists('css', '.layout__region--content .field--name-field-test-text');
+    $this->assertSession()->elementNotExists('css', '.field--name-field-test-text');
+
+    // Show the field.
+    $this->drupalGet('entity_test/structure/entity_test/display');
+    $this->getSession()->getPage()->pressButton('Show row weights');
+    $this->getSession()->getPage()->selectFieldOption('fields[field_test_text][region]', 'content');
+    $this->assertSession()->assertWaitOnAjaxRequest();
+    $this->submitForm([], 'Save');
+
+    // Switch the layout to one column.
+    $this->click('#edit-field-layouts');
+    $this->getSession()->getPage()->selectFieldOption('field_layout', 'layout_test_1col');
+    $this->assertSession()->assertWaitOnAjaxRequest();
+    $this->submitForm([], 'Save');
 
     // Change the layout for the "test" view mode. See
     // core.entity_view_mode.entity_test.test.yml.
@@ -58,26 +71,27 @@ public function testEntityViewModes() {
     $this->getSession()->getPage()->checkField('display_modes_custom[test]');
     $this->submitForm([], 'Save');
     $this->clickLink('configure them');
-    $this->getSession()->getPage()->pressButton('Show row weights');
-    $this->getSession()->getPage()->selectFieldOption('fields[field_test_text][region]', 'content');
+    $this->click('#edit-field-layouts');
+    $this->getSession()->getPage()->selectFieldOption('field_layout', 'layout_test_2col');
+    $this->assertSession()->assertWaitOnAjaxRequest();
+    $this->submitForm([], 'Save');
+
+    // Move the field to a new region.
+    $this->getSession()->getPage()->selectFieldOption('fields[field_test_text][region]', 'right');
     $this->assertSession()->assertWaitOnAjaxRequest();
     $this->submitForm([], 'Save');
 
     // Each view mode has a different layout.
     $this->drupalGet('entity_test/1/test');
-    $this->assertSession()->elementExists('css', '.layout__region--content .field--name-field-test-text');
+    $this->assertSession()->elementExists('css', '.layout-example-2col .region-right .field--name-field-test-text');
     $this->drupalGet('entity_test/1');
-    $this->assertSession()->elementNotExists('css', '.layout__region--content .field--name-field-test-text');
+    $this->assertSession()->elementExists('css', '.layout-example-1col .region-top .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.
-    $this->drupalGet('entity_test/manage/1/edit');
-    $this->assertFieldInRegion('field_test_text[0][value]', 'content');
-
     // The one-column layout is in use.
     $this->drupalGet('entity_test/structure/entity_test/form-display');
     $this->assertEquals(['Content', 'Disabled'], $this->getRegionTitles());
diff --git a/core/modules/field_layout/tests/src/Unit/FieldLayoutBuilderTest.php b/core/modules/field_layout/tests/src/Unit/FieldLayoutBuilderTest.php
deleted file mode 100644
index 8e6bf95..0000000
--- a/core/modules/field_layout/tests/src/Unit/FieldLayoutBuilderTest.php
+++ /dev/null
@@ -1,308 +0,0 @@
-<?php
-
-namespace Drupal\Tests\field_layout\Unit;
-
-use Drupal\Core\Entity\EntityFieldManagerInterface;
-use Drupal\Core\Field\FieldDefinitionInterface;
-use Drupal\field_layout\Display\EntityDisplayWithLayoutInterface;
-use Drupal\field_layout\FieldLayoutBuilder;
-use Drupal\Core\Layout\LayoutPluginManagerInterface;
-use Drupal\Core\Layout\LayoutDefault;
-use Drupal\Core\Layout\LayoutDefinition;
-use Drupal\Tests\UnitTestCase;
-use Prophecy\Argument;
-
-/**
- * @coversDefaultClass \Drupal\field_layout\FieldLayoutBuilder
- * @group field_layout
- */
-class FieldLayoutBuilderTest extends UnitTestCase {
-
-  /**
-   * @var \Drupal\Core\Layout\LayoutPluginManager|\Prophecy\Prophecy\ProphecyInterface
-   */
-  protected $layoutPluginManager;
-
-  /**
-   * @var \Drupal\Core\Entity\EntityFieldManagerInterface|\Prophecy\Prophecy\ProphecyInterface
-   */
-  protected $entityFieldManager;
-
-  /**
-   * @var \Drupal\field_layout\FieldLayoutBuilder
-   */
-  protected $fieldLayoutBuilder;
-
-  /**
-   * @var \Drupal\Core\Layout\LayoutInterface
-   */
-  protected $layoutPlugin;
-
-  /**
-   * @var \Drupal\Core\Layout\LayoutDefinition
-   */
-  protected $pluginDefinition;
-
-  /**
-   * {@inheritdoc}
-   */
-  protected function setUp() {
-    parent::setUp();
-
-    $this->pluginDefinition = new LayoutDefinition([
-      'library' => 'field_layout/drupal.layout.twocol',
-      'theme_hook' => 'layout__twocol',
-      'regions' => [
-        'left' => [
-          'label' => 'Left',
-        ],
-        'right' => [
-          'label' => 'Right',
-        ],
-      ],
-    ]);
-    $this->layoutPlugin = new LayoutDefault([], 'two_column', $this->pluginDefinition);
-
-    $this->layoutPluginManager = $this->prophesize(LayoutPluginManagerInterface::class);
-    $this->layoutPluginManager->getDefinition('unknown', FALSE)->willReturn(NULL);
-    $this->layoutPluginManager->getDefinition('two_column', FALSE)->willReturn($this->pluginDefinition);
-
-    $this->entityFieldManager = $this->prophesize(EntityFieldManagerInterface::class);
-
-    $this->fieldLayoutBuilder = new FieldLayoutBuilder($this->layoutPluginManager->reveal(), $this->entityFieldManager->reveal());
-  }
-
-  /**
-   * @covers ::buildView
-   * @covers ::getFields
-   */
-  public function testBuildView() {
-    $definitions = [];
-    $non_configurable_field_definition = $this->prophesize(FieldDefinitionInterface::class);
-    $non_configurable_field_definition->isDisplayConfigurable('view')->willReturn(FALSE);
-    $definitions['non_configurable_field'] = $non_configurable_field_definition->reveal();
-    $definitions['non_configurable_field_with_extra_field'] = $non_configurable_field_definition->reveal();
-    $this->entityFieldManager->getFieldDefinitions('the_entity_type_id', 'the_entity_type_bundle')->willReturn($definitions);
-    $extra_fields = [];
-    $extra_fields['non_configurable_field_with_extra_field'] = [
-      'label' => 'This non-configurable field is also defined in hook_entity_extra_field_info()',
-    ];
-    $this->entityFieldManager->getExtraFields('the_entity_type_id', 'the_entity_type_bundle')->willReturn($extra_fields);
-
-    $build = [
-      'test1' => [
-        '#markup' => 'Test1',
-      ],
-      'non_configurable_field' => [
-        '#markup' => 'Non-configurable',
-      ],
-      'non_configurable_field_with_extra_field' => [
-        '#markup' => 'Non-configurable with extra field',
-      ],
-    ];
-
-    $display = $this->prophesize(EntityDisplayWithLayoutInterface::class);
-    $display->getTargetEntityTypeId()->willReturn('the_entity_type_id');
-    $display->getTargetBundle()->willReturn('the_entity_type_bundle');
-    $display->getLayout()->willReturn($this->layoutPlugin);
-    $display->getLayoutId()->willReturn('two_column');
-    $display->getLayoutSettings()->willReturn([]);
-    $display->getComponents()->willReturn([
-      'test1' => [
-        'region' => 'right',
-      ],
-      'non_configurable_field' => [
-        'region' => 'left',
-      ],
-      'non_configurable_field_with_extra_field' => [
-        'region' => 'left',
-      ],
-    ]);
-
-    $expected = [
-      'non_configurable_field' => [
-        '#markup' => 'Non-configurable',
-      ],
-      '_field_layout' => [
-        'left' => [
-          'non_configurable_field_with_extra_field' => [
-            '#markup' => 'Non-configurable with extra field',
-          ],
-        ],
-        'right' => [
-          'test1' => [
-            '#markup' => 'Test1',
-          ],
-        ],
-        '#settings' => [],
-        '#layout' => $this->pluginDefinition,
-        '#theme' => 'layout__twocol',
-        '#attached' => [
-          'library' => [
-            'field_layout/drupal.layout.twocol',
-          ],
-        ],
-      ],
-    ];
-    $this->fieldLayoutBuilder->buildView($build, $display->reveal());
-    $this->assertEquals($expected, $build);
-    $this->assertSame($expected, $build);
-  }
-
-  /**
-   * @covers ::buildForm
-   * @covers ::getFields
-   */
-  public function testBuildForm() {
-    $definitions = [];
-    $non_configurable_field_definition = $this->prophesize(FieldDefinitionInterface::class);
-    $non_configurable_field_definition->isDisplayConfigurable('form')->willReturn(FALSE);
-    $definitions['non_configurable_field'] = $non_configurable_field_definition->reveal();
-    $this->entityFieldManager->getFieldDefinitions('the_entity_type_id', 'the_entity_type_bundle')->willReturn($definitions);
-    $this->entityFieldManager->getExtraFields('the_entity_type_id', 'the_entity_type_bundle')->willReturn([]);
-
-    $build = [
-      'test1' => [
-        '#markup' => 'Test1',
-      ],
-      'test2' => [
-        '#markup' => 'Test2',
-        '#group' => 'existing_group',
-      ],
-      'field_layout' => [
-        '#markup' => 'Field created through the UI happens to be named "Layout"',
-      ],
-      'non_configurable_field' => [
-        '#markup' => 'Non-configurable',
-      ],
-    ];
-
-    $display = $this->prophesize(EntityDisplayWithLayoutInterface::class);
-    $display->getTargetEntityTypeId()->willReturn('the_entity_type_id');
-    $display->getTargetBundle()->willReturn('the_entity_type_bundle');
-    $display->getLayout()->willReturn($this->layoutPlugin);
-    $display->getLayoutId()->willReturn('two_column');
-    $display->getLayoutSettings()->willReturn([]);
-    $display->getComponents()->willReturn([
-      'test1' => [
-        'region' => 'right',
-      ],
-      'test2' => [
-        'region' => 'left',
-      ],
-      'field_layout' => [
-        'region' => 'right',
-      ],
-      'non_configurable_field' => [
-        'region' => 'left',
-      ],
-    ]);
-
-    $expected = [
-      'test1' => [
-        '#markup' => 'Test1',
-        '#group' => 'right',
-      ],
-      'test2' => [
-        '#markup' => 'Test2',
-        '#group' => 'existing_group',
-      ],
-      'field_layout' => [
-        '#markup' => 'Field created through the UI happens to be named "Layout"',
-        '#group' => 'right',
-      ],
-      'non_configurable_field' => [
-        '#markup' => 'Non-configurable',
-      ],
-      '_field_layout' => [
-        'left' => [
-          '#process' => ['\Drupal\Core\Render\Element\RenderElement::processGroup'],
-          '#pre_render' => ['\Drupal\Core\Render\Element\RenderElement::preRenderGroup'],
-        ],
-        'right' => [
-          '#process' => ['\Drupal\Core\Render\Element\RenderElement::processGroup'],
-          '#pre_render' => ['\Drupal\Core\Render\Element\RenderElement::preRenderGroup'],
-        ],
-        '#settings' => [],
-        '#layout' => $this->pluginDefinition,
-        '#theme' => 'layout__twocol',
-        '#attached' => [
-          'library' => [
-            'field_layout/drupal.layout.twocol',
-          ],
-        ],
-      ],
-    ];
-    $this->fieldLayoutBuilder->buildForm($build, $display->reveal());
-    $this->assertEquals($expected, $build);
-    $this->assertSame($expected, $build);
-  }
-
-  /**
-   * @covers ::buildForm
-   */
-  public function testBuildFormEmpty() {
-    $definitions = [];
-    $non_configurable_field_definition = $this->prophesize(FieldDefinitionInterface::class);
-    $non_configurable_field_definition->isDisplayConfigurable('form')->willReturn(FALSE);
-    $definitions['non_configurable_field'] = $non_configurable_field_definition->reveal();
-    $this->entityFieldManager->getFieldDefinitions('the_entity_type_id', 'the_entity_type_bundle')->willReturn($definitions);
-    $this->entityFieldManager->getExtraFields('the_entity_type_id', 'the_entity_type_bundle')->willReturn([]);
-
-    $build = [
-      'non_configurable_field' => [
-        '#markup' => 'Non-configurable',
-      ],
-    ];
-
-    $display = $this->prophesize(EntityDisplayWithLayoutInterface::class);
-    $display->getTargetEntityTypeId()->willReturn('the_entity_type_id');
-    $display->getTargetBundle()->willReturn('the_entity_type_bundle');
-    $display->getLayout()->willReturn($this->layoutPlugin);
-    $display->getLayoutId()->willReturn('two_column');
-    $display->getLayoutSettings()->willReturn([]);
-    $display->getComponents()->willReturn([
-      'test1' => [
-        'region' => 'right',
-      ],
-      'non_configurable_field' => [
-        'region' => 'left',
-      ],
-    ]);
-
-    $expected = [
-      'non_configurable_field' => [
-        '#markup' => 'Non-configurable',
-      ],
-    ];
-    $this->fieldLayoutBuilder->buildForm($build, $display->reveal());
-    $this->assertSame($expected, $build);
-  }
-
-  /**
-   * @covers ::buildForm
-   */
-  public function testBuildFormNoLayout() {
-    $this->entityFieldManager->getFieldDefinitions(Argument::any(), Argument::any())->shouldNotBeCalled();
-
-    $build = [
-      'test1' => [
-        '#markup' => 'Test1',
-      ],
-    ];
-
-    $display = $this->prophesize(EntityDisplayWithLayoutInterface::class);
-    $display->getLayoutId()->willReturn('unknown');
-    $display->getLayoutSettings()->willReturn([]);
-    $display->getComponents()->shouldNotBeCalled();
-
-    $expected = [
-      'test1' => [
-        '#markup' => 'Test1',
-      ],
-    ];
-    $this->fieldLayoutBuilder->buildForm($build, $display->reveal());
-    $this->assertSame($expected, $build);
-  }
-
-}
diff --git a/core/modules/forum/config/optional/core.entity_form_display.comment.comment_forum.default.yml b/core/modules/forum/config/optional/core.entity_form_display.comment.comment_forum.default.yml
index 4738bbb..b426ba2 100644
--- a/core/modules/forum/config/optional/core.entity_form_display.comment.comment_forum.default.yml
+++ b/core/modules/forum/config/optional/core.entity_form_display.comment.comment_forum.default.yml
@@ -31,3 +31,5 @@ content:
       placeholder: ''
     third_party_settings: {  }
 hidden: {  }
+layout_id: layout_default
+layout_settings: {  }
diff --git a/core/modules/forum/config/optional/core.entity_form_display.node.forum.default.yml b/core/modules/forum/config/optional/core.entity_form_display.node.forum.default.yml
index 6773d32..5b09113 100644
--- a/core/modules/forum/config/optional/core.entity_form_display.node.forum.default.yml
+++ b/core/modules/forum/config/optional/core.entity_form_display.node.forum.default.yml
@@ -73,3 +73,5 @@ content:
       placeholder: ''
     third_party_settings: {  }
 hidden: {  }
+layout_id: layout_default
+layout_settings: {  }
diff --git a/core/modules/forum/config/optional/core.entity_form_display.taxonomy_term.forums.default.yml b/core/modules/forum/config/optional/core.entity_form_display.taxonomy_term.forums.default.yml
index 50df98a..434cbda 100644
--- a/core/modules/forum/config/optional/core.entity_form_display.taxonomy_term.forums.default.yml
+++ b/core/modules/forum/config/optional/core.entity_form_display.taxonomy_term.forums.default.yml
@@ -27,3 +27,5 @@ content:
     third_party_settings: {  }
 hidden:
   forum_container: true
+layout_id: layout_default
+layout_settings: {  }
diff --git a/core/modules/forum/config/optional/core.entity_view_display.comment.comment_forum.default.yml b/core/modules/forum/config/optional/core.entity_view_display.comment.comment_forum.default.yml
index befeba8..a7fe3d8 100644
--- a/core/modules/forum/config/optional/core.entity_view_display.comment.comment_forum.default.yml
+++ b/core/modules/forum/config/optional/core.entity_view_display.comment.comment_forum.default.yml
@@ -22,3 +22,5 @@ content:
     weight: 100
     region: content
 hidden: {  }
+layout_id: layout_default
+layout_settings: {  }
diff --git a/core/modules/forum/config/optional/core.entity_view_display.node.forum.default.yml b/core/modules/forum/config/optional/core.entity_view_display.node.forum.default.yml
index f3e8c5c..6ff22bb 100644
--- a/core/modules/forum/config/optional/core.entity_view_display.node.forum.default.yml
+++ b/core/modules/forum/config/optional/core.entity_view_display.node.forum.default.yml
@@ -44,3 +44,5 @@ content:
       link: true
     third_party_settings: {  }
 hidden: {  }
+layout_id: layout_default
+layout_settings: {  }
diff --git a/core/modules/forum/config/optional/core.entity_view_display.node.forum.teaser.yml b/core/modules/forum/config/optional/core.entity_view_display.node.forum.teaser.yml
index 7b174f4..c9bd86d 100644
--- a/core/modules/forum/config/optional/core.entity_view_display.node.forum.teaser.yml
+++ b/core/modules/forum/config/optional/core.entity_view_display.node.forum.teaser.yml
@@ -36,3 +36,5 @@ content:
     third_party_settings: {  }
 hidden:
   comment_forum: true
+layout_id: layout_default
+layout_settings: {  }
diff --git a/core/modules/forum/config/optional/core.entity_view_display.taxonomy_term.forums.default.yml b/core/modules/forum/config/optional/core.entity_view_display.taxonomy_term.forums.default.yml
index b326039..4835e73 100644
--- a/core/modules/forum/config/optional/core.entity_view_display.taxonomy_term.forums.default.yml
+++ b/core/modules/forum/config/optional/core.entity_view_display.taxonomy_term.forums.default.yml
@@ -20,3 +20,5 @@ content:
     label: above
 hidden:
   forum_container: true
+layout_id: layout_default
+layout_settings: {  }
diff --git a/core/modules/image/tests/src/Kernel/ImageFormatterTest.php b/core/modules/image/tests/src/Kernel/ImageFormatterTest.php
index e994f12..ad93a52 100644
--- a/core/modules/image/tests/src/Kernel/ImageFormatterTest.php
+++ b/core/modules/image/tests/src/Kernel/ImageFormatterTest.php
@@ -96,6 +96,8 @@ public function testImageFormatterCacheTags() {
 
     // Generate the render array to verify if the cache tags are as expected.
     $build = $this->display->build($entity);
+    // Build a fake array that provides the structure assumed by the test.
+    $build = [$this->fieldName => $this->display->getFieldFromBuild($this->fieldName, $build)];
 
     $this->assertEquals($entity->{$this->fieldName}[0]->entity->getCacheTags(), $build[$this->fieldName][0]['#cache']['tags'], 'First image cache tags is as expected');
     $this->assertEquals($entity->{$this->fieldName}[1]->entity->getCacheTags(), $build[$this->fieldName][1]['#cache']['tags'], 'Second image cache tags is as expected');
@@ -144,6 +146,8 @@ public function testImageFormatterSvg() {
     $this->display->setComponent($this->fieldName, $component)->save();
 
     $build = $this->display->build($entity);
+    // Build a fake array that provides the structure assumed by the test.
+    $build = [$this->fieldName => $this->display->getFieldFromBuild($this->fieldName, $build)];
 
     // The first image is a PNG, so it is supported by the GD image toolkit.
     // The image style should be applied with its cache tags, image derivative
diff --git a/core/modules/layout_discovery/layout_discovery.info.yml b/core/modules/layout_discovery/layout_discovery.info.yml
index a9a4139..d0c8d3a 100644
--- a/core/modules/layout_discovery/layout_discovery.info.yml
+++ b/core/modules/layout_discovery/layout_discovery.info.yml
@@ -1,6 +1,6 @@
 name: 'Layout Discovery'
 type: module
 description: 'Provides a way for modules or themes to register layouts.'
-package: Core (Experimental)
+package: Core
 version: VERSION
 core: 8.x
diff --git a/core/modules/layout_discovery/layout_discovery.module b/core/modules/layout_discovery/layout_discovery.module
index 3cffee9..bacfff8 100644
--- a/core/modules/layout_discovery/layout_discovery.module
+++ b/core/modules/layout_discovery/layout_discovery.module
@@ -17,23 +17,3 @@ function layout_discovery_help($route_name) {
       return $output;
   }
 }
-
-/**
- * Implements hook_theme().
- */
-function layout_discovery_theme() {
-  return \Drupal::service('plugin.manager.core.layout')->getThemeImplementations();
-}
-
-/**
- * Prepares variables for layout templates.
- *
- * @param array &$variables
- *   An associative array containing:
- *   - content: An associative array containing the properties of the element.
- *     Properties used: #settings, #layout.
- */
-function template_preprocess_layout(&$variables) {
-  $variables['settings'] = isset($variables['content']['#settings']) ? $variables['content']['#settings'] : [];
-  $variables['layout'] = isset($variables['content']['#layout']) ? $variables['content']['#layout'] : [];
-}
diff --git a/core/modules/layout_discovery/tests/src/Kernel/LayoutTest.php b/core/modules/layout_discovery/tests/src/Kernel/LayoutTest.php
index fa8fdd6..b859797 100644
--- a/core/modules/layout_discovery/tests/src/Kernel/LayoutTest.php
+++ b/core/modules/layout_discovery/tests/src/Kernel/LayoutTest.php
@@ -80,6 +80,17 @@ protected function render(array &$elements) {
    * Data provider for testRenderLayout().
    */
   public function renderLayoutData() {
+    $data['layout_default'] = [
+      'layout_default',
+      [],
+      [
+        'content' => [
+          '#markup' => "This is the content\n",
+        ],
+      ],
+      ['This is the content'],
+    ];
+
     $html = [];
     $html[] = '<div data-drupal-selector="edit-layout" class="layout layout--onecol">';
     $html[] = '<div class="layout__region layout__region--content">';
diff --git a/core/modules/node/src/Tests/NodeEntityViewModeAlterTest.php b/core/modules/node/src/Tests/NodeEntityViewModeAlterTest.php
index 901887b..15d2559 100644
--- a/core/modules/node/src/Tests/NodeEntityViewModeAlterTest.php
+++ b/core/modules/node/src/Tests/NodeEntityViewModeAlterTest.php
@@ -43,7 +43,7 @@ public function testNodeViewModeChange() {
     $this->assertNoText('Data that should appear only in the body for the node.', 'Body text not present');
 
     // Test that the correct build mode has been set.
-    $build = $this->drupalBuildEntityView($node);
+    $build = $this->drupalBuildFullEntityView($node);
     $this->assertEqual($build['#view_mode'], 'teaser', 'The view mode has correctly been set to teaser.');
   }
 
diff --git a/core/modules/node/src/Tests/SummaryLengthTest.php b/core/modules/node/src/Tests/SummaryLengthTest.php
index e953882..536cc6e 100644
--- a/core/modules/node/src/Tests/SummaryLengthTest.php
+++ b/core/modules/node/src/Tests/SummaryLengthTest.php
@@ -46,6 +46,9 @@ public function testSummaryLength() {
     // 200 characters in length and so does not include 'What is a Drupalism?'.
     $content = $this->drupalBuildEntityView($node, 'teaser');
     $this->assertTrue(strlen($content['body'][0]['#markup']) < 200, 'Teaser is less than 200 characters long.');
+
+    // Render the entire content array.
+    $content = $this->drupalBuildFullEntityView($node, 'teaser');
     $this->setRawContent($renderer->renderRoot($content));
     $this->assertText($node->label());
     $this->assertNoRaw($expected);
diff --git a/core/modules/options/tests/options_config_install_test/config/install/core.entity_form_display.node.options_install_test.default.yml b/core/modules/options/tests/options_config_install_test/config/install/core.entity_form_display.node.options_install_test.default.yml
index ff5f0ec..414865c 100644
--- a/core/modules/options/tests/options_config_install_test/config/install/core.entity_form_display.node.options_install_test.default.yml
+++ b/core/modules/options/tests/options_config_install_test/config/install/core.entity_form_display.node.options_install_test.default.yml
@@ -59,3 +59,5 @@ content:
     third_party_settings: {  }
 hidden: {  }
 third_party_settings: {  }
+layout_id: layout_default
+layout_settings: {  }
diff --git a/core/modules/options/tests/options_config_install_test/config/install/core.entity_view_display.node.options_install_test.default.yml b/core/modules/options/tests/options_config_install_test/config/install/core.entity_view_display.node.options_install_test.default.yml
index aaea1cb..13b6334 100644
--- a/core/modules/options/tests/options_config_install_test/config/install/core.entity_view_display.node.options_install_test.default.yml
+++ b/core/modules/options/tests/options_config_install_test/config/install/core.entity_view_display.node.options_install_test.default.yml
@@ -25,3 +25,5 @@ content:
 hidden:
   langcode: true
 third_party_settings: {  }
+layout_id: layout_default
+layout_settings: {  }
diff --git a/core/modules/options/tests/options_config_install_test/config/install/core.entity_view_display.node.options_install_test.teaser.yml b/core/modules/options/tests/options_config_install_test/config/install/core.entity_view_display.node.options_install_test.teaser.yml
index 6e79af9..47f26ea 100644
--- a/core/modules/options/tests/options_config_install_test/config/install/core.entity_view_display.node.options_install_test.teaser.yml
+++ b/core/modules/options/tests/options_config_install_test/config/install/core.entity_view_display.node.options_install_test.teaser.yml
@@ -27,3 +27,5 @@ content:
 hidden:
   langcode: true
 third_party_settings: {  }
+layout_id: layout_default
+layout_settings: {  }
diff --git a/core/modules/rdf/rdf.module b/core/modules/rdf/rdf.module
index 0afcb09..e445e1a 100644
--- a/core/modules/rdf/rdf.module
+++ b/core/modules/rdf/rdf.module
@@ -5,6 +5,7 @@
  * Enables semantically enriched output for Drupal sites in the form of RDFa.
  */
 
+use Drupal\comment\CommentInterface;
 use Drupal\Core\Routing\RouteMatchInterface;
 use Drupal\Core\Template\Attribute;
 use Drupal\rdf\Entity\RdfMapping;
@@ -502,7 +503,19 @@ function rdf_preprocess_comment(&$variables) {
     $variables['title_attributes']['property'] = $title_mapping['properties'];
     $variables['title_attributes']['datatype'] = '';
   }
+}
 
+/**
+ * Implements hook_entity_display_build_alter().
+ */
+function rdf_entity_display_build_alter(&$build, $context) {
+  if (!($context['entity'] instanceof CommentInterface)) {
+    return;
+  }
+
+  $comment = $context['entity'];
+  $rdf_metadata_attributes = [];
+  $mapping = rdf_get_mapping('comment', $comment->bundle());
   // Annotates the parent relationship between the current comment and the node
   // it belongs to. If available, the parent comment is also annotated.
   // @todo When comments are turned into fields, this should be changed.
@@ -514,7 +527,7 @@ function rdf_preprocess_comment(&$variables) {
     // The parent entity URI is precomputed as part of the rdf_data so that it
     // can be cached as part of the entity.
     $parent_entity_attributes['resource'] = $comment->rdf_data['entity_uri'];
-    $variables['rdf_metadata_attributes'][] = $parent_entity_attributes;
+    $rdf_metadata_attributes[] = $parent_entity_attributes;
 
     // Adds the relation to parent comment, if it exists.
     if ($comment->hasParentComment()) {
@@ -522,19 +535,19 @@ function rdf_preprocess_comment(&$variables) {
       // The parent comment URI is precomputed as part of the rdf_data so that
       // it can be cached as part of the entity.
       $parent_comment_attributes['resource'] = $comment->rdf_data['pid_uri'];
-      $variables['rdf_metadata_attributes'][] = $parent_comment_attributes;
+      $rdf_metadata_attributes[] = $parent_comment_attributes;
     }
   }
   // Adds RDF metadata markup above comment body if any.
-  if (!empty($variables['rdf_metadata_attributes']) && isset($variables['content']['comment_body'])) {
+  if (!empty($rdf_metadata_attributes) && isset($build['comment_body'])) {
     $rdf_metadata = [
       '#theme' => 'rdf_metadata',
-      '#metadata' => $variables['rdf_metadata_attributes'],
+      '#metadata' => $rdf_metadata_attributes,
     ];
-    if (!empty($variables['content']['comment_body']['#prefix'])) {
-      $rdf_metadata['#suffix'] = $variables['content']['comment_body']['#prefix'];
+    if (!empty($build['comment_body']['#prefix'])) {
+      $rdf_metadata['#suffix'] = $build['comment_body']['#prefix'];
     }
-    $variables['content']['comment_body']['#prefix'] = drupal_render($rdf_metadata);
+    $build['comment_body']['#prefix'] = drupal_render($rdf_metadata);
   }
 }
 
diff --git a/core/modules/simpletest/src/WebTestBase.php b/core/modules/simpletest/src/WebTestBase.php
index 2491bc8..8e7f094 100644
--- a/core/modules/simpletest/src/WebTestBase.php
+++ b/core/modules/simpletest/src/WebTestBase.php
@@ -210,6 +210,17 @@ public function __construct($test_id = NULL) {
   }
 
   /**
+   * Builds the portion of a renderable view of an entity that contains fields.
+   *
+   * @see ::buildEntityView()
+   */
+  protected function drupalBuildEntityView(EntityInterface $entity, $view_mode = 'full', $langcode = NULL, $reset = FALSE) {
+    $build = $this->drupalBuildFullEntityView($entity, $view_mode, $langcode, $reset);
+    // By default all fields will be nested in the onecol layout.
+    return $build['_layout']['content'];
+  }
+
+  /**
    * Builds the renderable view of an entity.
    *
    * Entities postpone the composition of their renderable arrays to #pre_render
@@ -229,11 +240,13 @@ public function __construct($test_id = NULL) {
    *   the current content language.
    * @param bool $reset
    *   (optional) Whether to clear the cache for this entity.
+   *
    * @return array
+   *   The render array for the given entity.
    *
    * @see drupal_render()
    */
-  protected function drupalBuildEntityView(EntityInterface $entity, $view_mode = 'full', $langcode = NULL, $reset = FALSE) {
+  protected function drupalBuildFullEntityView(EntityInterface $entity, $view_mode = 'full', $langcode = NULL, $reset = FALSE) {
     $ensure_fully_built = function(&$elements) use (&$ensure_fully_built) {
       // If the default values for this element have not been loaded yet, populate
       // them.
diff --git a/core/modules/system/system.module b/core/modules/system/system.module
index a1a6b71..3bf4767 100644
--- a/core/modules/system/system.module
+++ b/core/modules/system/system.module
@@ -268,7 +268,7 @@ function system_theme() {
       ],
       'template' => 'entity-add-list',
     ],
-  ]);
+  ], \Drupal::service('plugin.manager.core.layout')->getThemeImplementations());
 }
 
 /**
diff --git a/core/modules/layout_discovery/templates/layout.html.twig b/core/modules/system/templates/layout.html.twig
similarity index 100%
copy from core/modules/layout_discovery/templates/layout.html.twig
copy to core/modules/system/templates/layout.html.twig
diff --git a/core/modules/user/user.module b/core/modules/user/user.module
index 61faa3b..b1e3f79 100644
--- a/core/modules/user/user.module
+++ b/core/modules/user/user.module
@@ -392,13 +392,14 @@ function user_user_view(array &$build, UserInterface $account, EntityViewDisplay
 }
 
 /**
- * Implements hook_ENTITY_TYPE_view_alter() for user entities.
+ * Implements hook_entity_display_build_alter().
  *
  * This function adds a default alt tag to the user_picture field to maintain
  * accessibility.
  */
-function user_user_view_alter(array &$build, UserInterface $account, EntityViewDisplayInterface $display) {
-  if (user_picture_enabled() && !empty($build['user_picture'])) {
+function user_entity_display_build_alter(&$build, $context) {
+  $account = $context['entity'];
+  if ($account instanceof UserInterface && user_picture_enabled() && !empty($build['user_picture'])) {
     foreach (Element::children($build['user_picture']) as $key) {
       $item = $build['user_picture'][$key]['#item'];
       if (!$item->get('alt')->getValue()) {
diff --git a/core/modules/views/src/Entity/Render/EntityFieldRenderer.php b/core/modules/views/src/Entity/Render/EntityFieldRenderer.php
index 3c38da1..95ef7fe 100644
--- a/core/modules/views/src/Entity/Render/EntityFieldRenderer.php
+++ b/core/modules/views/src/Entity/Render/EntityFieldRenderer.php
@@ -232,6 +232,7 @@ protected function buildFields(array $values) {
             $display->setComponent($field->definition['field_name'], [
               'type' => $field->options['type'],
               'settings' => $field->options['settings'],
+              'region' => $display->getDefaultRegion(),
             ]);
           }
           // Let the display build the render array for the entities.
@@ -240,7 +241,7 @@ protected function buildFields(array $values) {
           // row indexes and field IDs.
           foreach ($display_build as $row_index => $entity_build) {
             foreach ($display_fields['field_ids'] as $field_id => $field) {
-              $build[$row_index][$field_id] = !empty($entity_build[$field->definition['field_name']]) ? $entity_build[$field->definition['field_name']] : [];
+              $build[$row_index][$field_id] = $display->getFieldFromBuild($field->definition['field_name'], $entity_build);
             }
           }
         }
diff --git a/core/profiles/standard/config/install/core.entity_form_display.block_content.basic.default.yml b/core/profiles/standard/config/install/core.entity_form_display.block_content.basic.default.yml
index 7ccb5b0..11465aa 100644
--- a/core/profiles/standard/config/install/core.entity_form_display.block_content.basic.default.yml
+++ b/core/profiles/standard/config/install/core.entity_form_display.block_content.basic.default.yml
@@ -29,3 +29,5 @@ content:
       placeholder: ''
     third_party_settings: {  }
 hidden: {  }
+layout_id: layout_default
+layout_settings: {  }
diff --git a/core/profiles/standard/config/install/core.entity_form_display.comment.comment.default.yml b/core/profiles/standard/config/install/core.entity_form_display.comment.comment.default.yml
index 1010be2..954293f 100644
--- a/core/profiles/standard/config/install/core.entity_form_display.comment.comment.default.yml
+++ b/core/profiles/standard/config/install/core.entity_form_display.comment.comment.default.yml
@@ -31,3 +31,5 @@ content:
       placeholder: ''
     third_party_settings: {  }
 hidden: {  }
+layout_id: layout_default
+layout_settings: {  }
diff --git a/core/profiles/standard/config/install/core.entity_form_display.node.article.default.yml b/core/profiles/standard/config/install/core.entity_form_display.node.article.default.yml
index c94e36e..b8f906c 100644
--- a/core/profiles/standard/config/install/core.entity_form_display.node.article.default.yml
+++ b/core/profiles/standard/config/install/core.entity_form_display.node.article.default.yml
@@ -91,3 +91,5 @@ content:
       placeholder: ''
     third_party_settings: {  }
 hidden: {  }
+layout_id: layout_default
+layout_settings: {  }
diff --git a/core/profiles/standard/config/install/core.entity_form_display.node.page.default.yml b/core/profiles/standard/config/install/core.entity_form_display.node.page.default.yml
index 0b7ffd1..9037c51 100644
--- a/core/profiles/standard/config/install/core.entity_form_display.node.page.default.yml
+++ b/core/profiles/standard/config/install/core.entity_form_display.node.page.default.yml
@@ -65,3 +65,5 @@ content:
       placeholder: ''
     third_party_settings: {  }
 hidden: {  }
+layout_id: layout_default
+layout_settings: {  }
diff --git a/core/profiles/standard/config/install/core.entity_form_display.user.user.default.yml b/core/profiles/standard/config/install/core.entity_form_display.user.user.default.yml
index 6832229..8443df5 100644
--- a/core/profiles/standard/config/install/core.entity_form_display.user.user.default.yml
+++ b/core/profiles/standard/config/install/core.entity_form_display.user.user.default.yml
@@ -33,3 +33,5 @@ content:
     weight: -1
     region: content
 hidden: {  }
+layout_id: layout_default
+layout_settings: {  }
diff --git a/core/profiles/standard/config/install/core.entity_view_display.block_content.basic.default.yml b/core/profiles/standard/config/install/core.entity_view_display.block_content.basic.default.yml
index e494882..f24c9e4 100644
--- a/core/profiles/standard/config/install/core.entity_view_display.block_content.basic.default.yml
+++ b/core/profiles/standard/config/install/core.entity_view_display.block_content.basic.default.yml
@@ -19,3 +19,5 @@ content:
     settings: {  }
     third_party_settings: {  }
 hidden: {  }
+layout_id: layout_default
+layout_settings: {  }
diff --git a/core/profiles/standard/config/install/core.entity_view_display.comment.comment.default.yml b/core/profiles/standard/config/install/core.entity_view_display.comment.comment.default.yml
index 6ae213d..10d9376 100644
--- a/core/profiles/standard/config/install/core.entity_view_display.comment.comment.default.yml
+++ b/core/profiles/standard/config/install/core.entity_view_display.comment.comment.default.yml
@@ -22,3 +22,5 @@ content:
     weight: 100
     region: content
 hidden: {  }
+layout_id: layout_default
+layout_settings: {  }
diff --git a/core/profiles/standard/config/install/core.entity_view_display.node.article.default.yml b/core/profiles/standard/config/install/core.entity_view_display.node.article.default.yml
index 5c43252..512550f 100644
--- a/core/profiles/standard/config/install/core.entity_view_display.node.article.default.yml
+++ b/core/profiles/standard/config/install/core.entity_view_display.node.article.default.yml
@@ -58,3 +58,5 @@ content:
 hidden:
   field_image: true
   field_tags: true
+layout_id: layout_default
+layout_settings: {  }
diff --git a/core/profiles/standard/config/install/core.entity_view_display.node.article.rss.yml b/core/profiles/standard/config/install/core.entity_view_display.node.article.rss.yml
index 84660b6..a0402c3 100644
--- a/core/profiles/standard/config/install/core.entity_view_display.node.article.rss.yml
+++ b/core/profiles/standard/config/install/core.entity_view_display.node.article.rss.yml
@@ -23,3 +23,5 @@ hidden:
   comment: true
   field_image: true
   field_tags: true
+layout_id: layout_default
+layout_settings: {  }
diff --git a/core/profiles/standard/config/install/core.entity_view_display.node.article.teaser.yml b/core/profiles/standard/config/install/core.entity_view_display.node.article.teaser.yml
index 7b96908..4be0fb3 100644
--- a/core/profiles/standard/config/install/core.entity_view_display.node.article.teaser.yml
+++ b/core/profiles/standard/config/install/core.entity_view_display.node.article.teaser.yml
@@ -50,3 +50,5 @@ hidden:
   comment: true
   field_image: true
   field_tags: true
+layout_id: layout_default
+layout_settings: {  }
diff --git a/core/profiles/standard/config/install/core.entity_view_display.node.page.default.yml b/core/profiles/standard/config/install/core.entity_view_display.node.page.default.yml
index 8afd942..4119e46 100644
--- a/core/profiles/standard/config/install/core.entity_view_display.node.page.default.yml
+++ b/core/profiles/standard/config/install/core.entity_view_display.node.page.default.yml
@@ -23,3 +23,5 @@ content:
     weight: 101
     region: content
 hidden: {  }
+layout_id: layout_default
+layout_settings: {  }
diff --git a/core/profiles/standard/config/install/core.entity_view_display.node.page.teaser.yml b/core/profiles/standard/config/install/core.entity_view_display.node.page.teaser.yml
index bc7a68c..63e3903 100644
--- a/core/profiles/standard/config/install/core.entity_view_display.node.page.teaser.yml
+++ b/core/profiles/standard/config/install/core.entity_view_display.node.page.teaser.yml
@@ -25,3 +25,5 @@ content:
     weight: 101
     region: content
 hidden: {  }
+layout_id: layout_default
+layout_settings: {  }
diff --git a/core/profiles/standard/config/install/core.entity_view_display.user.user.compact.yml b/core/profiles/standard/config/install/core.entity_view_display.user.user.compact.yml
index 2ff13ad..c61652f 100644
--- a/core/profiles/standard/config/install/core.entity_view_display.user.user.compact.yml
+++ b/core/profiles/standard/config/install/core.entity_view_display.user.user.compact.yml
@@ -24,3 +24,5 @@ content:
     label: hidden
 hidden:
   member_for: true
+layout_id: layout_default
+layout_settings: {  }
diff --git a/core/profiles/standard/config/install/core.entity_view_display.user.user.default.yml b/core/profiles/standard/config/install/core.entity_view_display.user.user.default.yml
index ef1fdd7..6c9b20f 100644
--- a/core/profiles/standard/config/install/core.entity_view_display.user.user.default.yml
+++ b/core/profiles/standard/config/install/core.entity_view_display.user.user.default.yml
@@ -25,3 +25,5 @@ content:
     third_party_settings: {  }
     label: hidden
 hidden: {  }
+layout_id: layout_default
+layout_settings: {  }
diff --git a/core/modules/field_layout/tests/src/Kernel/FieldLayoutEntityDisplayTest.php b/core/tests/Drupal/KernelTests/Core/Entity/EntityViewDisplayTest.php
similarity index 67%
rename from core/modules/field_layout/tests/src/Kernel/FieldLayoutEntityDisplayTest.php
rename to core/tests/Drupal/KernelTests/Core/Entity/EntityViewDisplayTest.php
index 3ca5e59..fefc173 100644
--- a/core/modules/field_layout/tests/src/Kernel/FieldLayoutEntityDisplayTest.php
+++ b/core/tests/Drupal/KernelTests/Core/Entity/EntityViewDisplayTest.php
@@ -1,20 +1,20 @@
 <?php
 
-namespace Drupal\Tests\field_layout\Kernel;
+namespace Drupal\KernelTests\Core\Entity;
 
-use Drupal\field_layout\Entity\FieldLayoutEntityViewDisplay;
+use Drupal\Core\Entity\Entity\EntityViewDisplay;
 use Drupal\KernelTests\KernelTestBase;
 
 /**
- * @coversDefaultClass \Drupal\field_layout\Entity\FieldLayoutEntityDisplayTrait
- * @group field_layout
+ * @coversDefaultClass \Drupal\Core\Entity\Entity\EntityViewDisplay
+ * @group Entity
  */
-class FieldLayoutEntityDisplayTest extends KernelTestBase {
+class EntityViewDisplayTest extends KernelTestBase {
 
   /**
    * {@inheritdoc}
    */
-  protected static $modules = ['layout_discovery', 'field_layout', 'entity_test', 'field_layout_test', 'system'];
+  protected static $modules = ['entity_test', 'field_layout_test'];
 
   /**
    * @covers ::preSave
@@ -22,7 +22,7 @@ class FieldLayoutEntityDisplayTest extends KernelTestBase {
    */
   public function testPreSave() {
     // Create an entity display with one hidden and one visible field.
-    $entity_display = FieldLayoutEntityViewDisplay::create([
+    $entity_display = EntityViewDisplay::create([
       'targetEntityType' => 'entity_test',
       'bundle' => 'entity_test',
       'mode' => 'default',
@@ -38,12 +38,6 @@ public function testPreSave() {
       'langcode' => 'en',
       'status' => TRUE,
       'dependencies' => [],
-      'third_party_settings' => [
-        'field_layout' => [
-          'id' => 'layout_onecol',
-          'settings' => [],
-        ],
-      ],
       'id' => 'entity_test.entity_test.default',
       'targetEntityType' => 'entity_test',
       'bundle' => 'entity_test',
@@ -57,6 +51,8 @@ public function testPreSave() {
         ],
       ],
       'hidden' => [],
+      'layout_id' => 'layout_default',
+      'layout_settings' => [],
     ];
     $this->assertEntityValues($expected, $entity_display->toArray());
 
@@ -67,8 +63,6 @@ public function testPreSave() {
     // The dependencies have been updated.
     $expected['dependencies']['module'] = [
       'entity_test',
-      'field_layout',
-      'layout_discovery',
     ];
     // A third party setting is added by the entity_test module.
     $expected['third_party_settings']['entity_test'] = ['foo' => 'bar'];
@@ -83,15 +77,9 @@ public function testPreSave() {
 
     // Assign a new layout that has default settings and complex dependencies,
     // but do not save yet.
-    $entity_display->setLayoutId('test_layout_main_and_footer');
+    $entity_display->setLayoutFromId('test_layout_main_and_footer');
 
-    // The default settings were added.
-    $expected['third_party_settings']['field_layout'] = [
-      'id' => 'test_layout_main_and_footer',
-      'settings' => [
-        'setting_1' => 'Default',
-      ],
-    ];
+    $expected['layout_id'] = 'test_layout_main_and_footer';
     // The field was moved to the default region.
     $expected['content']['foo'] = [
       'type' => 'visible',
@@ -102,23 +90,26 @@ public function testPreSave() {
     ];
     $this->assertEntityValues($expected, $entity_display->toArray());
 
+    $entity_display->save();
     // After saving, the dependencies have been updated.
-    $entity_display->save();
     $expected['dependencies']['module'] = [
       'dependency_from_annotation',
       'dependency_from_calculateDependencies',
       'entity_test',
-      'field_layout',
       'field_layout_test',
     ];
+    // The default settings were added.
+    $expected['layout_settings'] = [
+      'setting_1' => 'Default',
+    ];
     $this->assertEntityValues($expected, $entity_display->toArray());
 
     // Assign a layout with provided settings.
-    $entity_display->setLayoutId('test_layout_main_and_footer', ['setting_1' => 'foobar']);
+    $entity_display->setLayoutFromId('test_layout_main_and_footer', ['setting_1' => 'foobar']);
     $entity_display->save();
 
     // The setting overrides the default value.
-    $expected['third_party_settings']['field_layout']['settings']['setting_1'] = 'foobar';
+    $expected['layout_settings']['setting_1'] = 'foobar';
     $this->assertEntityValues($expected, $entity_display->toArray());
 
     // Move a field to the non-default region.
@@ -132,37 +123,19 @@ public function testPreSave() {
     $this->assertEntityValues($expected, $entity_display->toArray());
 
     // Assign a different layout that shares the same non-default region.
-    $entity_display->setLayoutId('test_layout_content_and_footer');
+    $entity_display->setLayoutFromId('test_layout_content_and_footer');
     $entity_display->save();
 
     // The dependencies have been updated.
     $expected['dependencies']['module'] = [
       'entity_test',
-      'field_layout',
       'field_layout_test',
     ];
     // The layout has been updated.
-    $expected['third_party_settings']['field_layout'] = [
-      'id' => 'test_layout_content_and_footer',
-      'settings' => [],
-    ];
+    $expected['layout_id'] = 'test_layout_content_and_footer';
+    $expected['layout_settings'] = [];
     // The field remains in its current region instead of moving to the default.
     $this->assertEntityValues($expected, $entity_display->toArray());
-
-    $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');
-
-    // The dependencies have been updated.
-    $expected['dependencies']['module'] = [
-      'entity_test',
-    ];
-    // All field_layout settings were removed.
-    unset($expected['third_party_settings']['field_layout']);
-    // The field has returned to the default content region.
-    $expected['content']['foo']['region'] = 'content';
-    $this->assertEntityValues($expected, $entity_display->toArray());
   }
 
   /**
diff --git a/core/tests/Drupal/Tests/Core/Config/Entity/EntityDisplayBaseTest.php b/core/tests/Drupal/Tests/Core/Config/Entity/EntityDisplayBaseTest.php
index 8dd7e77..45aa24c 100644
--- a/core/tests/Drupal/Tests/Core/Config/Entity/EntityDisplayBaseTest.php
+++ b/core/tests/Drupal/Tests/Core/Config/Entity/EntityDisplayBaseTest.php
@@ -2,6 +2,8 @@
 
 namespace Drupal\Tests\Core\Config\Entity;
 
+use Drupal\Core\DependencyInjection\ContainerBuilder;
+use Drupal\Core\Layout\LayoutPluginManagerInterface;
 use Drupal\Tests\UnitTestCase;
 
 /**
@@ -59,6 +61,11 @@ public function testGetTargetBundle() {
    * @covers ::setTargetBundle
    */
   public function testSetTargetBundle() {
+    $layout_plugin_manager = $this->prophesize(LayoutPluginManagerInterface::class);
+    $container = new ContainerBuilder();
+    $container->set('plugin.manager.core.layout', $layout_plugin_manager->reveal());
+    \Drupal::setContainer($container);
+
     $mock = $this->getMockForAbstractClass('\Drupal\Core\Entity\EntityDisplayBase', [], '', FALSE);
     $reflection = new \ReflectionProperty($mock, 'bundle');
     $reflection->setAccessible(TRUE);
diff --git a/core/tests/Drupal/Tests/Core/Entity/Display/EntityFormDisplayTest.php b/core/tests/Drupal/Tests/Core/Entity/Display/EntityFormDisplayTest.php
new file mode 100644
index 0000000..289f100
--- /dev/null
+++ b/core/tests/Drupal/Tests/Core/Entity/Display/EntityFormDisplayTest.php
@@ -0,0 +1,226 @@
+<?php
+
+namespace Drupal\Tests\Core\Entity\Display;
+
+use Drupal\Core\DependencyInjection\ContainerBuilder;
+use Drupal\Core\Entity\Entity\EntityFormDisplay;
+use Drupal\Core\Entity\EntityFieldManagerInterface;
+use Drupal\Core\Entity\EntityTypeInterface;
+use Drupal\Core\Entity\EntityTypeManagerInterface;
+use Drupal\Core\Entity\FieldableEntityInterface;
+use Drupal\Core\Field\FieldDefinitionInterface;
+use Drupal\Core\Field\WidgetPluginManager;
+use Drupal\Core\Form\FormState;
+use Drupal\Core\Layout\LayoutDefault;
+use Drupal\Core\Layout\LayoutDefinition;
+use Drupal\Core\Layout\LayoutPluginManagerInterface;
+use Drupal\Core\Render\RendererInterface;
+use Drupal\Tests\UnitTestCase;
+
+/**
+ * @coversDefaultClass \Drupal\Core\Entity\Entity\EntityFormDisplay
+ * @group Entity
+ */
+class EntityFormDisplayTest extends UnitTestCase {
+
+  /**
+   * The entity field manager.
+   *
+   * @var \Drupal\Core\Entity\EntityFieldManagerInterface|\Prophecy\Prophecy\ProphecyInterface
+   */
+  protected $entityFieldManager;
+
+  /**
+   * A layout definition.
+   *
+   * @var \Drupal\Core\Layout\LayoutDefinition
+   */
+  protected $pluginDefinition;
+
+  /**
+   * {@inheritdoc}
+   */
+  protected function setUp() {
+    parent::setUp();
+
+    $this->pluginDefinition = new LayoutDefinition([
+      'library' => 'system/drupal.layout.twocol',
+      'theme_hook' => 'layout__twocol',
+      'regions' => [
+        'left' => [
+          'label' => 'Left',
+        ],
+        'right' => [
+          'label' => 'Right',
+        ],
+      ],
+    ]);
+    $layout_plugin = new LayoutDefault([], 'two_column', $this->pluginDefinition);
+
+    $layout_plugin_manager = $this->prophesize(LayoutPluginManagerInterface::class);
+    $layout_plugin_manager->getDefinition('unknown', FALSE)->willReturn(NULL);
+    $layout_plugin_manager->getDefinition('two_column', FALSE)->willReturn($this->pluginDefinition);
+    $layout_plugin_manager->createInstance('two_column', [])->willReturn($layout_plugin);
+
+    $renderer = $this->prophesize(RendererInterface::class);
+
+    $entity_type = $this->prophesize(EntityTypeInterface::class);
+    $entity_type->entityClassImplements(FieldableEntityInterface::class)->willReturn(TRUE);
+
+    $entity_type_manager = $this->prophesize(EntityTypeManagerInterface::class);
+    $entity_type_manager->getDefinition('the_entity_type_id')->willReturn($entity_type->reveal());
+
+    $widget_manager = $this->prophesize(WidgetPluginManager::class);
+
+    $this->entityFieldManager = $this->prophesize(EntityFieldManagerInterface::class);
+
+    $container = new ContainerBuilder();
+    $container->set('entity_field.manager', $this->entityFieldManager->reveal());
+    $container->set('entity_type.manager', $entity_type_manager->reveal());
+    $container->set('plugin.manager.field.widget', $widget_manager->reveal());
+    $container->set('renderer', $renderer->reveal());
+    $container->set('plugin.manager.core.layout', $layout_plugin_manager->reveal());
+    \Drupal::setContainer($container);
+  }
+
+  /**
+   * @covers ::applyLayout
+   * @covers ::getFields
+   */
+  public function testApplyLayout() {
+    $non_configurable_field_definition = $this->prophesize(FieldDefinitionInterface::class);
+    $non_configurable_field_definition->isDisplayConfigurable('form')->willReturn(FALSE);
+
+    $definitions = [];
+    $definitions['non_configurable_field'] = $non_configurable_field_definition->reveal();
+    $this->entityFieldManager->getFieldDefinitions('the_entity_type_id', 'the_entity_type_bundle')->willReturn($definitions);
+
+    $this->entityFieldManager->getExtraFields('the_entity_type_id', 'the_entity_type_bundle')->willReturn([]);
+
+    $build = [
+      'test1' => [
+        '#markup' => 'Test1',
+      ],
+      'test2' => [
+        '#markup' => 'Test2',
+        '#group' => 'existing_group',
+      ],
+      'layout' => [
+        '#markup' => 'Field created through the UI happens to be named "Layout"',
+      ],
+      'non_configurable_field' => [
+        '#markup' => 'Non-configurable',
+      ],
+    ];
+
+    $display = new EntityFormDisplay(
+      [
+        'targetEntityType' => 'the_entity_type_id',
+        'bundle' => 'the_entity_type_bundle',
+        'layout_id' => 'two_column',
+        'layout_settings' => [],
+        'content' => [
+          'test1' => [
+            'region' => 'right',
+          ],
+          'test2' => [
+            'region' => 'left',
+          ],
+          'layout' => [
+            'region' => 'right',
+          ],
+          'non_configurable_field' => [
+            'region' => 'left',
+          ],
+        ],
+      ],
+      'entity_form_display'
+    );
+
+    $expected = [
+      'test1' => [
+        '#markup' => 'Test1',
+        '#group' => 'right',
+      ],
+      'test2' => [
+        '#markup' => 'Test2',
+        '#group' => 'existing_group',
+      ],
+      'layout' => [
+        '#markup' => 'Field created through the UI happens to be named "Layout"',
+        '#group' => 'right',
+      ],
+      'non_configurable_field' => [
+        '#markup' => 'Non-configurable',
+      ],
+      '_layout' => [
+        'left' => [
+          '#process' => ['\Drupal\Core\Render\Element\RenderElement::processGroup'],
+          '#pre_render' => ['\Drupal\Core\Render\Element\RenderElement::preRenderGroup'],
+        ],
+        'right' => [
+          '#process' => ['\Drupal\Core\Render\Element\RenderElement::processGroup'],
+          '#pre_render' => ['\Drupal\Core\Render\Element\RenderElement::preRenderGroup'],
+        ],
+        '#settings' => [],
+        '#layout' => $this->pluginDefinition,
+        '#theme' => 'layout__twocol',
+        '#attached' => [
+          'library' => [
+            'system/drupal.layout.twocol',
+          ],
+        ],
+      ],
+    ];
+
+    $build = $display->applyLayout($build, new FormState(), []);
+    $this->assertEquals($expected, $build);
+    $this->assertSame($expected, $build);
+  }
+
+  /**
+   * @covers ::applyLayout
+   * @covers ::getFields
+   */
+  public function testApplyLayoutEmpty() {
+    $definitions = [];
+    $non_configurable_field_definition = $this->prophesize(FieldDefinitionInterface::class);
+    $non_configurable_field_definition->isDisplayConfigurable('form')->willReturn(FALSE);
+    $definitions['non_configurable_field'] = $non_configurable_field_definition->reveal();
+    $this->entityFieldManager->getFieldDefinitions('the_entity_type_id', 'the_entity_type_bundle')->willReturn($definitions);
+    $this->entityFieldManager->getExtraFields('the_entity_type_id', 'the_entity_type_bundle')->willReturn([]);
+
+    $build = [
+      'non_configurable_field' => [
+        '#markup' => 'Non-configurable',
+      ],
+    ];
+
+    $display = new EntityFormDisplay(
+      [
+        'targetEntityType' => 'the_entity_type_id',
+        'bundle' => 'the_entity_type_bundle',
+        'layout_id' => 'two_column',
+        'layout_settings' => [],
+        'content' => [
+          'test1' => [
+            'region' => 'right',
+          ],
+          'non_configurable_field' => [
+            'region' => 'left',
+          ],
+        ],
+      ],
+      'entity_form_display'
+    );
+
+    $expected = [
+      'non_configurable_field' => [
+        '#markup' => 'Non-configurable',
+      ],
+    ];
+    $build = $display->applyLayout($build, new FormState(), []);
+    $this->assertSame($expected, $build);
+  }
+
+}
diff --git a/core/tests/Drupal/Tests/Core/Entity/Display/EntityViewDisplayTest.php b/core/tests/Drupal/Tests/Core/Entity/Display/EntityViewDisplayTest.php
new file mode 100644
index 0000000..952d116
--- /dev/null
+++ b/core/tests/Drupal/Tests/Core/Entity/Display/EntityViewDisplayTest.php
@@ -0,0 +1,176 @@
+<?php
+
+namespace Drupal\Tests\Core\Entity\Display;
+
+use Drupal\Core\DependencyInjection\ContainerBuilder;
+use Drupal\Core\Entity\Entity\EntityViewDisplay;
+use Drupal\Core\Entity\EntityFieldManagerInterface;
+use Drupal\Core\Entity\EntityTypeInterface;
+use Drupal\Core\Entity\EntityTypeManagerInterface;
+use Drupal\Core\Entity\FieldableEntityInterface;
+use Drupal\Core\Field\FieldDefinitionInterface;
+use Drupal\Core\Field\FormatterPluginManager;
+use Drupal\Core\Layout\LayoutDefault;
+use Drupal\Core\Layout\LayoutDefinition;
+use Drupal\Core\Layout\LayoutPluginManagerInterface;
+use Drupal\Core\Render\RendererInterface;
+use Drupal\Tests\UnitTestCase;
+
+/**
+ * @coversDefaultClass \Drupal\Core\Entity\Entity\EntityViewDisplay
+ * @group Entity
+ */
+class EntityViewDisplayTest extends UnitTestCase {
+
+  /**
+   * The entity field manager.
+   *
+   * @var \Drupal\Core\Entity\EntityFieldManagerInterface|\Prophecy\Prophecy\ProphecyInterface
+   */
+  protected $entityFieldManager;
+
+  /**
+   * A layout definition.
+   *
+   * @var \Drupal\Core\Layout\LayoutDefinition
+   */
+  protected $pluginDefinition;
+
+  /**
+   * {@inheritdoc}
+   */
+  protected function setUp() {
+    parent::setUp();
+
+    $this->pluginDefinition = new LayoutDefinition([
+      'library' => 'system/drupal.layout.twocol',
+      'theme_hook' => 'layout__twocol',
+      'regions' => [
+        'left' => [
+          'label' => 'Left',
+        ],
+        'right' => [
+          'label' => 'Right',
+        ],
+      ],
+    ]);
+    $layout_plugin = new LayoutDefault([], 'two_column', $this->pluginDefinition);
+
+    $layout_plugin_manager = $this->prophesize(LayoutPluginManagerInterface::class);
+    $layout_plugin_manager->getDefinition('unknown', FALSE)->willReturn(NULL);
+    $layout_plugin_manager->getDefinition('two_column', FALSE)->willReturn($this->pluginDefinition);
+    $layout_plugin_manager->createInstance('two_column', [])->willReturn($layout_plugin);
+
+    $renderer = $this->prophesize(RendererInterface::class);
+
+    $entity_type = $this->prophesize(EntityTypeInterface::class);
+    $entity_type->entityClassImplements(FieldableEntityInterface::class)->willReturn(TRUE);
+
+    $entity_type_manager = $this->prophesize(EntityTypeManagerInterface::class);
+    $entity_type_manager->getDefinition('the_entity_type_id')->willReturn($entity_type->reveal());
+
+    $formatter_manager = $this->prophesize(FormatterPluginManager::class);
+
+    $this->entityFieldManager = $this->prophesize(EntityFieldManagerInterface::class);
+
+    $container = new ContainerBuilder();
+    $container->set('entity_field.manager', $this->entityFieldManager->reveal());
+    $container->set('entity_type.manager', $entity_type_manager->reveal());
+    $container->set('plugin.manager.field.formatter', $formatter_manager->reveal());
+    $container->set('renderer', $renderer->reveal());
+    $container->set('plugin.manager.core.layout', $layout_plugin_manager->reveal());
+    \Drupal::setContainer($container);
+  }
+
+  /**
+   * @covers ::applyLayout
+   * @covers ::getFields
+   */
+  public function testApplyLayout() {
+    $non_configurable_field_definition = $this->prophesize(FieldDefinitionInterface::class);
+    $non_configurable_field_definition->isDisplayConfigurable('view')->willReturn(FALSE);
+
+    $definitions = [];
+    $definitions['non_configurable_field'] = $non_configurable_field_definition->reveal();
+    $definitions['non_configurable_field_with_extra_field'] = $non_configurable_field_definition->reveal();
+    $this->entityFieldManager->getFieldDefinitions('the_entity_type_id', 'the_entity_type_bundle')->willReturn($definitions);
+
+    $extra_fields = [];
+    $extra_fields['display']['non_configurable_field_with_extra_field'] = [
+      'label' => 'This non-configurable field is also defined in hook_entity_extra_field_info()',
+    ];
+    $this->entityFieldManager->getExtraFields('the_entity_type_id', 'the_entity_type_bundle')->willReturn($extra_fields);
+
+    $build = [
+      'test1' => [
+        '#markup' => 'Test1',
+      ],
+      'non_configurable_field' => [
+        '#markup' => 'Non-configurable',
+      ],
+      'non_configurable_field_with_extra_field' => [
+        '#markup' => 'Non-configurable with extra field',
+      ],
+    ];
+
+    $display = new EntityViewDisplay(
+      [
+        'targetEntityType' => 'the_entity_type_id',
+        'bundle' => 'the_entity_type_bundle',
+        'layout_id' => 'two_column',
+        'layout_settings' => [],
+        'content' => [
+          'test1' => [
+            'region' => 'right',
+          ],
+          'non_configurable_field' => [
+            'region' => 'left',
+          ],
+          'non_configurable_field_with_extra_field' => [
+            'region' => 'left',
+          ],
+        ],
+      ],
+      'entity_view_display'
+    );
+
+    $expected = [
+      'non_configurable_field' => [
+        '#markup' => 'Non-configurable',
+      ],
+      '_layout' => [
+        'left' => [
+          'non_configurable_field_with_extra_field' => [
+            '#markup' => 'Non-configurable with extra field',
+          ],
+        ],
+        'right' => [
+          'test1' => [
+            '#markup' => 'Test1',
+          ],
+        ],
+        '#settings' => [],
+        '#layout' => $this->pluginDefinition,
+        '#theme' => 'layout__twocol',
+        '#attached' => [
+          'library' => [
+            'system/drupal.layout.twocol',
+          ],
+        ],
+      ],
+    ];
+
+    $method_ref = new \ReflectionMethod($display, 'applyLayout');
+    $method_ref->setAccessible(TRUE);
+    $method_ref->invokeArgs($display, [&$build]);
+    $this->assertEquals($expected, $build);
+    $this->assertSame($expected, $build);
+
+    // Use getFieldFromBuild() to manipulate the array.
+    $field_element = &$display->getFieldFromBuild('test1', $build);
+    $field_element['#title'] = 'My title';
+    $expected['_layout']['right']['test1']['#title'] = 'My title';
+    $this->assertEquals($expected, $build);
+  }
+
+}
diff --git a/core/themes/stable/templates/layout/layout--onecol.html.twig b/core/themes/stable/templates/layout/layout--onecol.html.twig
new file mode 100644
index 0000000..64b9b4e
--- /dev/null
+++ b/core/themes/stable/templates/layout/layout--onecol.html.twig
@@ -0,0 +1,25 @@
+{#
+/**
+ * @file
+ * Default theme implementation to display a one-column layout.
+ *
+ * Available variables:
+ * - content: The content for this layout.
+ * - attributes: HTML attributes for the layout <div>.
+ *
+ * @ingroup themeable
+ */
+#}
+{%
+  set classes = [
+    'layout',
+    'layout--onecol',
+  ]
+%}
+{% if content %}
+  <div{{ attributes.addClass(classes) }}>
+    <div class="layout__region layout__region--content">
+      {{ content.content }}
+    </div>
+  </div>
+{% endif %}
diff --git a/core/themes/stable/templates/layout/layout--threecol-25-50-25.html.twig b/core/themes/stable/templates/layout/layout--threecol-25-50-25.html.twig
new file mode 100644
index 0000000..8525525
--- /dev/null
+++ b/core/themes/stable/templates/layout/layout--threecol-25-50-25.html.twig
@@ -0,0 +1,54 @@
+{#
+/**
+ * @file
+ * Default theme implementation for a three column layout.
+ *
+ * This template provides a three column 25%-50%-25% display layout, with
+ * additional areas for the top and the bottom.
+ *
+ * Available variables:
+ * - content: The content for this layout.
+ * - attributes: HTML attributes for the layout <div>.
+ *
+ * @ingroup themeable
+ */
+#}
+{%
+  set classes = [
+    'layout',
+    'layout--threecol-25-50-25',
+  ]
+%}
+{% if content %}
+  <div{{ attributes.addClass(classes) }}>
+    {% if content.top %}
+      <div class="layout__region layout__region--top">
+        {{ content.top }}
+      </div>
+    {% endif %}
+
+    {% if content.first %}
+      <div class="layout__region layout__region--first">
+        {{ content.first }}
+      </div>
+    {% endif %}
+
+    {% if content.second %}
+      <div class="layout__region layout__region--second">
+        {{ content.second }}
+      </div>
+    {% endif %}
+
+    {% if content.third %}
+      <div class="layout__region layout__region--third">
+        {{ content.third }}
+      </div>
+    {% endif %}
+
+    {% if content.bottom %}
+      <div class="layout__region layout__region--bottom">
+        {{ content.bottom }}
+      </div>
+    {% endif %}
+  </div>
+{% endif %}
diff --git a/core/themes/stable/templates/layout/layout--threecol-33-34-33.html.twig b/core/themes/stable/templates/layout/layout--threecol-33-34-33.html.twig
new file mode 100644
index 0000000..5eabb04
--- /dev/null
+++ b/core/themes/stable/templates/layout/layout--threecol-33-34-33.html.twig
@@ -0,0 +1,54 @@
+{#
+/**
+ * @file
+ * Default theme implementation for a three column layout.
+ *
+ * This template provides a three column 33%-34%-33% display layout, with
+ * additional areas for the top and the bottom.
+ *
+ * Available variables:
+ * - content: The content for this layout.
+ * - attributes: HTML attributes for the layout <div>.
+ *
+ * @ingroup themeable
+ */
+#}
+{%
+  set classes = [
+    'layout',
+    'layout--threecol-33-34-33',
+  ]
+%}
+{% if content %}
+  <div{{ attributes.addClass(classes) }}>
+    {% if content.top %}
+      <div class="layout__region layout__region--top">
+        {{ content.top }}
+      </div>
+    {% endif %}
+
+    {% if content.first %}
+      <div class="layout__region layout__region--first">
+        {{ content.first }}
+      </div>
+    {% endif %}
+
+    {% if content.second %}
+      <div class="layout__region layout__region--second">
+        {{ content.second }}
+      </div>
+    {% endif %}
+
+    {% if content.third %}
+      <div class="layout__region layout__region--third">
+        {{ content.third }}
+      </div>
+    {% endif %}
+
+    {% if content.bottom %}
+      <div class="layout__region layout__region--bottom">
+        {{ content.bottom }}
+      </div>
+    {% endif %}
+  </div>
+{% endif %}
diff --git a/core/themes/stable/templates/layout/layout--twocol-bricks.html.twig b/core/themes/stable/templates/layout/layout--twocol-bricks.html.twig
new file mode 100644
index 0000000..1099577
--- /dev/null
+++ b/core/themes/stable/templates/layout/layout--twocol-bricks.html.twig
@@ -0,0 +1,66 @@
+{#
+/**
+ * @file
+ * Default theme implementation for a two column layout.
+ *
+ * This template provides a two column display layout with full width areas at
+ * the top, bottom and in the middle.
+ *
+ * Available variables:
+ * - content: The content for this layout.
+ * - attributes: HTML attributes for the layout <div>.
+ *
+ * @ingroup themeable
+ */
+#}
+{%
+  set classes = [
+    'layout',
+    'layout--twocol-bricks',
+  ]
+%}
+{% if content %}
+  <div{{ attributes.addClass(classes) }}>
+    {% if content.top %}
+      <div class="layout__region layout__region--top">
+        {{ content.top }}
+      </div>
+    {% endif %}
+
+    {% if content.first_above %}
+      <div class="layout__region layout__region--first-above">
+        {{ content.first_above }}
+      </div>
+    {% endif %}
+
+    {% if content.second_above %}
+      <div class="layout__region layout__region--second-above">
+        {{ content.second_above }}
+      </div>
+    {% endif %}
+
+    {% if content.middle %}
+      <div class="layout__region layout__region--middle">
+        {{ content.middle }}
+      </div>
+    {% endif %}
+
+    {% if content.first_below %}
+      <div class="layout__region layout__region--first-below">
+        {{ content.first_below }}
+      </div>
+    {% endif %}
+
+    {% if content.second_below %}
+      <div class="layout__region layout__region--second-below">
+        {{ content.second_below }}
+      </div>
+    {% endif %}
+
+    {% if content.bottom %}
+      <div class="layout__region layout__region--bottom">
+        {{ content.bottom }}
+      </div>
+    {% endif %}
+  </div>
+{% endif %}
diff --git a/core/themes/stable/templates/layout/layout--twocol.html.twig b/core/themes/stable/templates/layout/layout--twocol.html.twig
new file mode 100644
index 0000000..b416cbd
--- /dev/null
+++ b/core/themes/stable/templates/layout/layout--twocol.html.twig
@@ -0,0 +1,45 @@
+{#
+/**
+ * @file
+ * Default theme implementation to display a two-column layout.
+ *
+ * Available variables:
+ * - content: The content for this layout.
+ * - attributes: HTML attributes for the layout <div>.
+ *
+ * @ingroup themeable
+ */
+#}
+{%
+  set classes = [
+    'layout',
+    'layout--twocol',
+  ]
+%}
+{% if content %}
+  <div{{ attributes.addClass(classes) }}>
+    {% if content.top %}
+      <div class="layout__region layout__region--top">
+        {{ content.top }}
+      </div>
+    {% endif %}
+
+    {% if content.first %}
+      <div class="layout__region layout__region--first">
+        {{ content.first }}
+      </div>
+    {% endif %}
+
+    {% if content.second %}
+      <div class="layout__region layout__region--second">
+        {{ content.second }}
+      </div>
+    {% endif %}
+
+    {% if content.bottom %}
+      <div class="layout__region layout__region--bottom">
+        {{ content.bottom }}
+      </div>
+    {% endif %}
+  </div>
+{% endif %}
diff --git a/core/modules/layout_discovery/templates/layout.html.twig b/core/themes/stable/templates/layout/layout.html.twig
similarity index 100%
rename from core/modules/layout_discovery/templates/layout.html.twig
rename to core/themes/stable/templates/layout/layout.html.twig
