diff --git a/core/modules/aggregator/src/Controller/AggregatorController.php b/core/modules/aggregator/src/Controller/AggregatorController.php
index b85ca2c..c5fd4e6 100644
--- a/core/modules/aggregator/src/Controller/AggregatorController.php
+++ b/core/modules/aggregator/src/Controller/AggregatorController.php
@@ -174,9 +174,6 @@ public function pageLast() {
     $items = $this->entityManager()->getStorage('aggregator_item')->loadAll(20);
     $build = $this->buildPageList($items);
 
-    $config = $this->config('system.site');
-    $build['#cache']['tags'] = $config->getCacheTags();
-
     $build['#attached']['feed'][] = array('aggregator/rss', $this->config('system.site')->get('name') . ' ' . $this->t('aggregator'));
     return $build;
   }
diff --git a/core/modules/block/src/BlockForm.php b/core/modules/block/src/BlockForm.php
index 8a204ed..3ff21f6 100644
--- a/core/modules/block/src/BlockForm.php
+++ b/core/modules/block/src/BlockForm.php
@@ -10,7 +10,6 @@
 use Drupal\block\Event\BlockContextEvent;
 use Drupal\block\Event\BlockEvents;
 use Drupal\Component\Utility\Html;
-use Drupal\Core\Cache\Cache;
 use Drupal\Core\Entity\EntityForm;
 use Drupal\Core\Entity\EntityManagerInterface;
 use Drupal\Core\Executable\ExecutableManagerInterface;
@@ -109,11 +108,10 @@ public static function create(ContainerInterface $container) {
    */
   public function form(array $form, FormStateInterface $form_state) {
     $entity = $this->entity;
-    $config = $this->config('system.theme');
 
     // Store theme settings in $form_state for use below.
     if (!$theme = $entity->getTheme()) {
-      $theme = $config->get('default');
+      $theme = $this->config('system.theme')->get('default');
     }
     $form_state->set('block_theme', $theme);
 
diff --git a/core/modules/book/src/Form/BookSettingsForm.php b/core/modules/book/src/Form/BookSettingsForm.php
index dc05eb8..0db0dc5 100644
--- a/core/modules/book/src/Form/BookSettingsForm.php
+++ b/core/modules/book/src/Form/BookSettingsForm.php
@@ -7,7 +7,6 @@
 
 namespace Drupal\book\Form;
 
-use Drupal\Core\Cache\Cache;
 use Drupal\Core\Form\ConfigFormBase;
 use Drupal\Core\Form\FormStateInterface;
 
diff --git a/core/modules/contact/src/ContactFormEditForm.php b/core/modules/contact/src/ContactFormEditForm.php
index 4319abe..cc76152 100644
--- a/core/modules/contact/src/ContactFormEditForm.php
+++ b/core/modules/contact/src/ContactFormEditForm.php
@@ -7,7 +7,6 @@
 
 namespace Drupal\contact;
 
-use Drupal\Core\Cache\Cache;
 use Drupal\Core\Config\ConfigFactoryInterface;
 use Drupal\Core\Entity\EntityForm;
 use Drupal\Core\Entity\EntityTypeInterface;
@@ -35,8 +34,7 @@ public function form(array $form, FormStateInterface $form_state) {
     $form = parent::form($form, $form_state);
 
     $contact_form = $this->entity;
-    $config = $this->config('contact.settings');
-    $default_form = $config->get('default_form');
+    $default_form = $this->config('contact.settings')->get('default_form');
 
     $form['label'] = array(
       '#type' => 'textfield',
diff --git a/core/modules/language/src/Form/NegotiationSelectedForm.php b/core/modules/language/src/Form/NegotiationSelectedForm.php
index 4b212b7..57194f9 100644
--- a/core/modules/language/src/Form/NegotiationSelectedForm.php
+++ b/core/modules/language/src/Form/NegotiationSelectedForm.php
@@ -7,7 +7,6 @@
 
 namespace Drupal\language\Form;
 
-use Drupal\Core\Cache\Cache;
 use Drupal\Core\Form\FormStateInterface;
 use Drupal\Core\Language\LanguageInterface;
 use Drupal\Core\Form\ConfigFormBase;
@@ -42,7 +41,6 @@ public function buildForm(array $form, FormStateInterface $form_state) {
       '#languages' => LanguageInterface::STATE_CONFIGURABLE | LanguageInterface::STATE_SITE_DEFAULT,
       '#default_value' => $config->get('selected_langcode'),
     );
-    $form['#cache']['tags'] = Cache::mergeTags(isset($form['#cache']['tags']) ? $form['#cache']['tags'] : [],  $config->getCacheTags());
 
     return parent::buildForm($form, $form_state);
   }
diff --git a/core/modules/language/src/Form/NegotiationUrlForm.php b/core/modules/language/src/Form/NegotiationUrlForm.php
index dea6aba..fa1cd3e 100644
--- a/core/modules/language/src/Form/NegotiationUrlForm.php
+++ b/core/modules/language/src/Form/NegotiationUrlForm.php
@@ -7,7 +7,6 @@
 
 namespace Drupal\language\Form;
 
-use Drupal\Core\Cache\Cache;
 use Drupal\Core\Form\ConfigFormBase;
 use Drupal\Core\Form\FormStateInterface;
 use Drupal\Core\Language\LanguageManagerInterface;
@@ -132,8 +131,6 @@ public function buildForm(array $form, FormStateInterface $form_state) {
 
     $form_state->setRedirect('language.negotiation');
 
-    $form['#cache']['tags'] = Cache::mergeTags(isset($form['#cache']['tags']) ? $form['#cache']['tags'] : [],  $config->getCacheTags());
-
     return parent::buildForm($form, $form_state);
   }
 
diff --git a/core/modules/locale/src/Form/LocaleSettingsForm.php b/core/modules/locale/src/Form/LocaleSettingsForm.php
index 7685eb3..64460cc 100644
--- a/core/modules/locale/src/Form/LocaleSettingsForm.php
+++ b/core/modules/locale/src/Form/LocaleSettingsForm.php
@@ -6,7 +6,6 @@
 
 namespace Drupal\locale\Form;
 
-use Drupal\Core\Cache\Cache;
 use Drupal\Core\Form\ConfigFormBase;
 use Drupal\Core\Form\FormStateInterface;
 
@@ -86,8 +85,6 @@ public function buildForm(array $form, FormStateInterface $form_state) {
       '#description' => $this->t('How to treat existing translations when automatically updating the interface translations.'),
     );
 
-    $form['#cache']['tags'] = Cache::mergeTags(isset($form['#cache']['tags']) ? $form['#cache']['tags'] : [],  $config->getCacheTags());
-
     return parent::buildForm($form, $form_state);
   }
 
diff --git a/core/modules/search/src/Controller/SearchController.php b/core/modules/search/src/Controller/SearchController.php
index a78a11b..f3e0e06 100644
--- a/core/modules/search/src/Controller/SearchController.php
+++ b/core/modules/search/src/Controller/SearchController.php
@@ -7,7 +7,6 @@
 
 namespace Drupal\search\Controller;
 
-use Drupal\Core\Cache\Cache;
 use Drupal\Core\Config\ConfigFactory;
 use Drupal\Core\Controller\ControllerBase;
 use Drupal\search\SearchPageInterface;
@@ -90,9 +89,7 @@ public function view(Request $request, SearchPageInterface $entity) {
     if ($request->query->has('keys')) {
       if ($plugin->isSearchExecutable()) {
         // Log the search.
-        $config = $this->config('search.settings');
-        $build['#cache']['tags'] = Cache::mergeTags(isset($build['#cache']['tags']) ? $build['#cache']['tags'] : [],  $config->getCacheTags());
-        if ($config->get('logging')) {
+        if ($this->config('search.settings')->get('logging')) {
           $this->logger->notice('Searched %type for %keys.', array('%keys' => $keys, '%type' => $entity->label()));
         }
 
diff --git a/core/modules/taxonomy/src/TermForm.php b/core/modules/taxonomy/src/TermForm.php
index 2323fe7..daa2868 100644
--- a/core/modules/taxonomy/src/TermForm.php
+++ b/core/modules/taxonomy/src/TermForm.php
@@ -7,7 +7,6 @@
 
 namespace Drupal\taxonomy;
 
-use Drupal\Core\Cache\Cache;
 use Drupal\Core\Entity\ContentEntityForm;
 use Drupal\Core\Form\FormStateInterface;
 
@@ -23,7 +22,6 @@ public function form(array $form, FormStateInterface $form_state) {
     $term = $this->entity;
     $vocab_storage = $this->entityManager->getStorage('taxonomy_vocabulary');
     $vocabulary = $vocab_storage->load($term->bundle());
-    $config = $this->config('taxonomy.settings');
 
     $parent = array_keys(taxonomy_term_load_parents($term->id()));
     $form_state->set(['taxonomy', 'parent'], $parent);
@@ -40,7 +38,7 @@ public function form(array $form, FormStateInterface $form_state) {
     // numbers of items so we check for taxonomy.settings:override_selector
     // before loading the full vocabulary. Contrib modules can then intercept
     // before hook_form_alter to provide scalable alternatives.
-    if (!$config->get('override_selector')) {
+    if (!$this->config('taxonomy.settings')->get('override_selector')) {
       $parent = array_keys(taxonomy_term_load_parents($term->id()));
       $children = taxonomy_get_tree($vocabulary->id(), $term->id());
 
@@ -90,8 +88,6 @@ public function form(array $form, FormStateInterface $form_state) {
       '#value' => $term->id(),
     );
 
-    $form['#cache']['tags'] = Cache::mergeTags(isset($form['#cache']['tags']) ? $form['#cache']['tags'] : [],  $config->getCacheTags());
-
     return parent::form($form, $form_state, $term);
   }
 
diff --git a/core/modules/user/src/AccountForm.php b/core/modules/user/src/AccountForm.php
index 3bb8779..7ed3cbd 100644
--- a/core/modules/user/src/AccountForm.php
+++ b/core/modules/user/src/AccountForm.php
@@ -74,7 +74,6 @@ public function form(array $form, FormStateInterface $form_state) {
     $account = $this->entity;
     $user = $this->currentUser();
     $config = \Drupal::config('user.settings');
-    $form['#cache']['tags'] = $config->getCacheTags();
 
     $language_interface = \Drupal::languageManager()->getCurrentLanguage();
     $register = $account->isAnonymous();
diff --git a/core/modules/user/src/Form/UserCancelForm.php b/core/modules/user/src/Form/UserCancelForm.php
index 1626457..0297e70 100644
--- a/core/modules/user/src/Form/UserCancelForm.php
+++ b/core/modules/user/src/Form/UserCancelForm.php
@@ -7,7 +7,6 @@
 
 namespace Drupal\user\Form;
 
-use Drupal\Core\Cache\Cache;
 use Drupal\Core\Entity\ContentEntityConfirmFormBase;
 use Drupal\Core\Form\FormStateInterface;
 
@@ -77,7 +76,6 @@ public function getConfirmText() {
   public function buildForm(array $form, FormStateInterface $form_state) {
     $user = $this->currentUser();
     $this->cancelMethods = user_cancel_methods();
-    $config = $this->config('user.settings');
 
     // Display account cancellation method selection, if allowed.
     $admin_access = $user->hasPermission('administer users');
@@ -100,7 +98,7 @@ public function buildForm(array $form, FormStateInterface $form_state) {
       '#description' => $this->t('When enabled, the user must confirm the account cancellation via email.'),
     );
     // Also allow to send account canceled notification mail, if enabled.
-    $default_notify = $config->get('notify.status_canceled');
+    $default_notify = $this->config('user.settings')->get('notify.status_canceled');
     $form['user_cancel_notify'] = array(
       '#type' => 'checkbox',
       '#title' => $this->t('Notify user when account is canceled'),
@@ -114,8 +112,6 @@ public function buildForm(array $form, FormStateInterface $form_state) {
 
     $form = parent::buildForm($form, $form_state);
 
-    $form['#cache']['tags'] = Cache::mergeTags(isset($form['#cache']['tags']) ? $form['#cache']['tags'] : [],  $config->getCacheTags());
-
     return $form;
   }
 
diff --git a/sites/default/default.settings.php b/sites/default/default.settings.php
index 7cc10be..76d26fc 100644
--- a/sites/default/default.settings.php
+++ b/sites/default/default.settings.php
@@ -607,40 +607,3 @@
 # if (file_exists(__DIR__ . '/settings.local.php')) {
 #   include __DIR__ . '/settings.local.php';
 # }
-
-/**
- * Trusted host configuration.
- *
- * Drupal core can use the Symfony trusted host mechanism to prevent HTTP Host
- * header spoofing.
- *
- * To enable the trusted host mechanism, you enable your allowable hosts
- * in $settings['trusted_host_patterns']. This should be an array of regular
- * expression patterns, without delimiters, representing the hosts you would
- * like to allow.
- *
- * For example:
- * @code
- * $settings['trusted_host_patterns'] = array(
- *   '^www\.example\.com$',
- * );
- * @endcode
- * will allow the site to only run from www.example.com.
- *
- * If you are running multisite, or if you are running your site from
- * different domain names (eg, you don't redirect http://www.example.com to
- * http://example.com), you should specify all of the host patterns that are
- * allowed by your site.
- *
- * For example:
- * @code
- * $settings['trusted_host_patterns'] = array(
- *   '^example\.com$',
- *   '^.+\.example\.com$',
- *   '^example\.org',
- *   '^.+\.example\.org',
- * );
- * @endcode
- * will allow the site to run off of all variants of example.com and
- * example.org, with all subdomains included.
- */