diff --git a/core/includes/theme.inc b/core/includes/theme.inc
index 25cc7c4..e70656b 100644
--- a/core/includes/theme.inc
+++ b/core/includes/theme.inc
@@ -16,6 +16,7 @@
 use Drupal\Component\Utility\Unicode;
 use Drupal\Core\Config\Config;
 use Drupal\Core\Config\StorageException;
+use Drupal\Core\Extension\ThemeHandler;
 use Drupal\Core\Render\RenderableInterface;
 use Drupal\Core\Template\Attribute;
 use Drupal\Core\Theme\ThemeSettings;
@@ -319,7 +320,7 @@ function theme_get_setting($setting_name, $theme = NULL) {
       // If the theme does not support a particular feature, override the global
       // setting and set the value to NULL.
       if (!empty($theme_object->info['features'])) {
-        foreach (_system_default_theme_features() as $feature) {
+        foreach (ThemeHandler::$defaultFeatures as $feature) {
           if (!in_array($feature, $theme_object->info['features'])) {
             $cache[$theme]->set('features.' . $feature, NULL);
           }
diff --git a/core/lib/Drupal/Core/Extension/ThemeHandler.php b/core/lib/Drupal/Core/Extension/ThemeHandler.php
index 59cfd99..425ed03 100644
--- a/core/lib/Drupal/Core/Extension/ThemeHandler.php
+++ b/core/lib/Drupal/Core/Extension/ThemeHandler.php
@@ -9,6 +9,7 @@
 
 use Drupal\Core\Config\ConfigFactoryInterface;
 use Drupal\Core\State\StateInterface;
+use Drupal\Core\Theme\ThemeFeatures;
 
 /**
  * Default theme handler using the config system to store installation statuses.
@@ -16,21 +17,6 @@
 class ThemeHandler implements ThemeHandlerInterface {
 
   /**
-   * Contains the features enabled for themes by default.
-   *
-   * @var array
-   *
-   * @see _system_default_theme_features()
-   */
-  protected $defaultFeatures = array(
-    'favicon',
-    'logo',
-    'node_user_picture',
-    'comment_user_picture',
-    'comment_user_verification',
-  );
-
-  /**
    * A list of all currently available themes.
    *
    * @var array
@@ -271,7 +257,7 @@ public function rebuildThemeData() {
         'breadcrumb' => 'Breadcrumb',
       ),
       'description' => '',
-      'features' => $this->defaultFeatures,
+      'features' => ThemeFeatures::defaults(),
       'screenshot' => 'screenshot.png',
       'php' => DRUPAL_MINIMUM_PHP,
       'libraries' => array(),
diff --git a/core/lib/Drupal/Core/Theme/ThemeFeatures.php b/core/lib/Drupal/Core/Theme/ThemeFeatures.php
new file mode 100644
index 0000000..493c2c0
--- /dev/null
+++ b/core/lib/Drupal/Core/Theme/ThemeFeatures.php
@@ -0,0 +1,27 @@
+<?php
+
+/**
+ * @file
+ * Contains \Drupal\Core\Theme\ThemeFeatures.
+ */
+
+namespace Drupal\Core\Theme;
+
+class ThemeFeatures {
+
+  /**
+   * Returns the features enabled for themes by default.
+   *
+   * @return string[]
+   */
+  public static function defaults() {
+    return [
+      'favicon',
+      'logo',
+      'node_user_picture',
+      'comment_user_picture',
+      'comment_user_verification',
+    ];
+  }
+
+}
diff --git a/core/modules/system/system.module b/core/modules/system/system.module
index ae6142f..fa9f0fc 100644
--- a/core/modules/system/system.module
+++ b/core/modules/system/system.module
@@ -12,6 +12,7 @@
 use Drupal\Core\Database\Query\AlterableInterface;
 use Drupal\Core\Extension\Extension;
 use Drupal\Core\Extension\ExtensionDiscovery;
+use Drupal\Core\Extension\ThemeHandler;
 use Drupal\Core\Form\FormStateInterface;
 use Drupal\Core\KeyValueStore\KeyValueDatabaseExpirableFactory;
 use Drupal\Core\PageCache\RequestPolicyInterface;
@@ -20,6 +21,7 @@
 use Drupal\Core\Language\LanguageInterface;
 use Drupal\Core\Menu\MenuTreeParameters;
 use Drupal\Core\Extension\ModuleHandler;
+use Drupal\Core\Theme\ThemeFeatures;
 use Drupal\Core\Url;
 use Drupal\Core\Block\BlockPluginInterface;
 use Drupal\user\UserInterface;
@@ -1063,16 +1065,13 @@ function system_rebuild_module_data() {
 /**
  * Returns an array of default theme features.
  *
- * @see \Drupal\Core\Extension\ThemeHandler::$defaultFeatures
+ * @see \Drupal\Core\Theme\ThemeFeatures::defaults()
+ *
+ * @deprecated in Drupal 8.0.x, will be removed before Drupal 9.0.0.
+ *   Use \Drupal\Core\Theme\ThemeFeatures::defaults() instead.
  */
 function _system_default_theme_features() {
-  return array(
-    'favicon',
-    'logo',
-    'node_user_picture',
-    'comment_user_picture',
-    'comment_user_verification',
-  );
+  return ThemeFeatures::defaults();
 }
 
 /**