diff --git a/core/includes/theme.inc b/core/includes/theme.inc
index 951dce5..8d4dd14 100644
--- a/core/includes/theme.inc
+++ b/core/includes/theme.inc
@@ -1366,9 +1366,6 @@ function template_preprocess_page(&$variables) {
   $variables['base_path']         = base_path();
   $variables['front_page']        = \Drupal::url('<front>');
   $variables['language']          = $language_interface;
-  $variables['logo']              = theme_get_setting('logo.url');
-  $variables['site_name']         = String::checkPlain($site_config->get('name'));
-  $variables['site_slogan']       = Xss::filterAdmin($site_config->get('slogan'));
 
   // An exception might be thrown.
   try {
diff --git a/core/modules/system/src/Plugin/Block/SystemBrandingBlock.php b/core/modules/system/src/Plugin/Block/SystemBrandingBlock.php
index 44650dd..b850bf2 100644
--- a/core/modules/system/src/Plugin/Block/SystemBrandingBlock.php
+++ b/core/modules/system/src/Plugin/Block/SystemBrandingBlock.php
@@ -12,6 +12,7 @@
 use Drupal\Core\Config\ConfigFactoryInterface;
 use Drupal\Core\Form\FormStateInterface;
 use Drupal\Core\Plugin\ContainerFactoryPluginInterface;
+use Drupal\Component\Utility\String;
 use Drupal\Component\Utility\Xss;
 use Drupal\Core\Url;
 use Symfony\Component\DependencyInjection\ContainerInterface;
@@ -165,16 +166,16 @@ public function build() {
     $build = array();
     $site_config = $this->configFactory->get('system.site');
 
-    $logo = theme_get_setting('logo');
+    $logo_url = theme_get_setting('logo.url');
     $build['site_logo'] = array(
       '#theme' => 'image',
-      '#uri' => $logo['url'],
+      '#uri' => $logo_url,
       '#alt' => $this->t('Home'),
       '#access' => $this->configuration['use_site_logo'],
     );
 
     $build['site_name'] = array(
-      '#markup' => $site_config->get('name'),
+      '#markup' => String::checkPlain($site_config->get('name')),
       '#access' => $this->configuration['use_site_name'],
     );
 
diff --git a/core/themes/bartik/bartik.theme b/core/themes/bartik/bartik.theme
index 7148e84..0df7389 100644
--- a/core/themes/bartik/bartik.theme
+++ b/core/themes/bartik/bartik.theme
@@ -41,9 +41,6 @@ function bartik_preprocess_html(&$variables) {
  * Implements hook_preprocess_HOOK() for page templates.
  */
 function bartik_preprocess_page(&$variables) {
-  // Set the options that apply to both page and maintenance page.
-  _bartik_process_page($variables);
-
   // Since the title and the shortcut link are both block level elements,
   // positioning them next to each other is much simpler with a wrapper div.
   if (!empty($variables['title_suffix']['add_or_remove_shortcut']) && $variables['title']) {
@@ -76,9 +73,6 @@ function bartik_preprocess_maintenance_page(&$variables) {
 
   // Bartik has custom styling for the maintenance page.
   $variables['#attached']['library'][] = 'bartik/maintenance_page';
-
-  // Set the options that apply to both page and maintenance page.
-  _bartik_process_page($variables);
 }
 
 /**
@@ -108,23 +102,3 @@ function bartik_preprocess_block(&$variables) {
 function bartik_preprocess_menu(&$variables) {
   $variables['attributes']['class'][] = 'clearfix';
 }
-
-/**
- * Helper function for handling the site name and slogan.
- */
-function _bartik_process_page(&$variables) {
-  $site_config = \Drupal::config('system.site');
-  // Always print the site name and slogan, but if they are toggled off, we'll
-  // just hide them visually.
-  $variables['hide_site_name']   = theme_get_setting('features.name') ? FALSE : TRUE;
-  $variables['hide_site_slogan'] = theme_get_setting('features.slogan') ? FALSE : TRUE;
-  if ($variables['hide_site_name']) {
-    // If toggle_name is FALSE, the site_name will be empty, so we rebuild it.
-    $variables['site_name'] = String::checkPlain($site_config->get('name'));
-  }
-  if ($variables['hide_site_slogan']) {
-    // If toggle_site_slogan is FALSE, the site_slogan will be empty, so we
-    // rebuild it.
-    $variables['site_slogan'] = Xss::filterAdmin($site_config->get('slogan'));
-  }
-}
diff --git a/core/themes/bartik/templates/page.html.twig b/core/themes/bartik/templates/page.html.twig
index 231b057..be03746 100644
--- a/core/themes/bartik/templates/page.html.twig
+++ b/core/themes/bartik/templates/page.html.twig
@@ -20,17 +20,6 @@
  * Site identity:
  * - front_page: The URL of the front page. Use this instead of base_path when
  *   linking to the front page. This includes the language domain or prefix.
- * - logo: The url of the logo image, as defined in theme settings.
- * - site_name: The name of the site. This is empty when displaying the site
- *   name has been disabled in the theme settings.
- * - site_slogan: The slogan of the site. This is empty when displaying the site
- *   slogan has been disabled in theme settings.
- * - hide_site_name: A flag indicating if the site name has been toggled off on
- *   the theme settings page. If hidden, the "visually-hidden" class is added
- *   to make the site name visually hidden, but still accessible.
- * - hide_site_slogan: A flag indicating if the site slogan has been toggled off
- *   on the theme settings page. If hidden, the "visually-hidden" class is
- *   added to make the site slogan visually hidden, but still accessible.
  *
  * Page content (in order of occurrence in the default page.html.twig):
  * - title_prefix: Additional output populated by modules, intended to be
diff --git a/core/themes/classy/templates/layout/page.html.twig b/core/themes/classy/templates/layout/page.html.twig
index 94c90a5..52b05c4 100644
--- a/core/themes/classy/templates/layout/page.html.twig
+++ b/core/themes/classy/templates/layout/page.html.twig
@@ -19,11 +19,6 @@
  * Site identity:
  * - front_page: The URL of the front page. Use this instead of base_path when
  *   linking to the front page. This includes the language domain or prefix.
- * - logo: The url of the logo image, as defined in theme settings.
- * - site_name: The name of the site. This is empty when displaying the site
- *   name has been disabled in the theme settings.
- * - site_slogan: The slogan of the site. This is empty when displaying the site
- *   slogan has been disabled in theme settings.
  *
  * Page content (in order of occurrence in the default page.html.twig):
  * - title_prefix: Additional output populated by modules, intended to be
diff --git a/core/themes/seven/seven.theme b/core/themes/seven/seven.theme
index 621cf82..fff9da4 100644
--- a/core/themes/seven/seven.theme
+++ b/core/themes/seven/seven.theme
@@ -148,6 +148,7 @@ function seven_element_info_alter(&$type) {
 function seven_preprocess_install_page(&$variables) {
   // Seven has custom styling for the install page.
   $variables['#attached']['library'][] = 'seven/install-page';
+  $variables['site_name'] = String::checkPlain($site_config->get('name'));
 }
 
 /**
@@ -156,6 +157,7 @@ function seven_preprocess_install_page(&$variables) {
 function seven_preprocess_maintenance_page(&$variables) {
   // Seven has custom styling for the maintenance page.
   $variables['#attached']['library'][] = 'seven/maintenance-page';
+  $variables['site_name'] = String::checkPlain($site_config->get('name'));  
 }
 
 /**
diff --git a/core/themes/seven/templates/page.html.twig b/core/themes/seven/templates/page.html.twig
index 4110987..0cdf4a4 100644
--- a/core/themes/seven/templates/page.html.twig
+++ b/core/themes/seven/templates/page.html.twig
@@ -20,11 +20,6 @@
  * Site identity:
  * - front_page: The URL of the front page. Use this instead of base_path when
  *   linking to the front page. This includes the language domain or prefix.
- * - logo: The url of the logo image, as defined in theme settings.
- * - site_name: The name of the site. This is empty when displaying the site
- *   name has been disabled in the theme settings.
- * - site_slogan: The slogan of the site. This is empty when displaying the site
- *   slogan has been disabled in theme settings.
  *
  * Page content (in order of occurrence in the default page.html.twig):
  * - title_prefix: Additional output populated by modules, intended to be