only in patch2:
unchanged:
--- a/core/modules/layout/layouts/static/one-col/one-col.yml
+++ b/core/modules/layout/layouts/static/one-col/one-col.yml
@@ -1,7 +1,7 @@
-title: One column
-category: Columns: 1
+title: 'One column'
+category: 'Columns: 1'
 template: one-col
 regions:
   content:
-    label: Middle column
+    label: 'Middle column'
     type: content
\ No newline at end of file
only in patch2:
unchanged:
--- a/core/modules/layout/layouts/static/twocol/two-col.yml
+++ b/core/modules/layout/layouts/static/twocol/two-col.yml
@@ -1,12 +1,12 @@
-title: Two column
-category: Columns: 2
+title: 'Two column'
+category: 'Columns: 2'
 template: two-col
 stylesheets:
   - two-col.css
 regions:
   first:
-    label: Left side
+    label: 'Left side'
     type: content
   second:
-    label: Right side
+    label: 'Right side'
     type: aside
only in patch2:
unchanged:
--- a/core/modules/layout/lib/Drupal/layout/Plugin/Derivative/Layout.php
+++ b/core/modules/layout/lib/Drupal/layout/Plugin/Derivative/Layout.php
@@ -9,7 +9,7 @@
 
 use DirectoryIterator;
 use Drupal\Component\Plugin\Derivative\DerivativeInterface;
-use Drupal\Core\Config\FileStorage;
+use Drupal\Component\Yaml\Yaml;
 
 /**
  * Layout plugin derivative definition.
@@ -93,6 +93,7 @@ public function getDerivativeDefinitions(array $base_plugin_definition) {
    */
   protected function iterateDirectories($dir, $provider) {
     $directories = new DirectoryIterator($dir);
+    $yaml = new Yaml();
     foreach ($directories as $fileinfo) {
       if ($fileinfo->isDir() && !$fileinfo->isDot()) {
         // Keep discovering in subdirectories to arbitrary depth.
@@ -102,9 +103,8 @@ protected function iterateDirectories($dir, $provider) {
         // Declarative layout definitions are defined with a .yml file in a
         // layout subdirectory. This provides all information about the layout
         // such as layout markup template and CSS and JavaScript files to use.
-        $directory = new FileStorage($fileinfo->getPath());
         $key = $provider['provider'] . '__' .  $fileinfo->getBasename('.yml');
-        $this->derivatives[$key] = $directory->read($fileinfo->getBasename('.yml'));
+        $this->derivatives[$key] = $yaml->parse(file_get_contents($fileinfo->getRealPath()));
         $this->derivatives[$key]['theme'] = $key;
         $this->derivatives[$key]['path'] = $fileinfo->getPath();
         $this->derivatives[$key]['provider'] = $provider;
only in patch2:
unchanged:
--- a/core/modules/layout/tests/layouts/static/one-col/one-col.yml
+++ b/core/modules/layout/tests/layouts/static/one-col/one-col.yml
@@ -1,7 +1,7 @@
-title: Single column
-category: Columns: 1
+title: 'Single column'
+category: 'Columns: 1'
 template: one-col
 regions:
   middle:
-    label: Middle column
+    label: 'Middle column'
     type: content
only in patch2:
unchanged:
--- a/core/modules/layout/tests/themes/layout_test_theme/layouts/static/two-col/two-col.yml
+++ b/core/modules/layout/tests/themes/layout_test_theme/layouts/static/two-col/two-col.yml
@@ -1,12 +1,12 @@
-title: Two column
-category: Columns: 2
+title: 'Two column'
+category: 'Columns: 2'
 template: two-col
 stylesheets:
   - two-col.css
 regions:
   left:
-    label: Left side
+    label: 'Left side'
     type: content
   right:
-    label: Right side
+    label: 'Right side'
     type: aside
\ No newline at end of file
only in patch2:
unchanged:
--- a/core/modules/user/tests/modules/user_test_views/test_views/views.view.test_user_uid_argument.yml
+++ b/core/modules/user/tests/modules/user_test_views/test_views/views.view.test_user_uid_argument.yml
@@ -17,7 +17,7 @@ display:
           table: users
           field: uid
           title_enable: true
-          title: %1
+          title: '%1'
           plugin_id: user_uid
     display_plugin: default
     display_title: Master