diff -u b/core/lib/Drupal/Core/Config/ConfigImporter.php b/core/lib/Drupal/Core/Config/ConfigImporter.php
--- b/core/lib/Drupal/Core/Config/ConfigImporter.php
+++ b/core/lib/Drupal/Core/Config/ConfigImporter.php
@@ -459,7 +459,7 @@
 
       // We're done.
       $this->resetLists();
-      // Leave the context used during import and reset the ConfigFactory's
+      // Leave the context used during import and clear the ConfigFactory's
       // static cache.
       $this->configFactory->leaveContext()->reset();
     }
reverted:
--- b/core/modules/views/lib/Drupal/views/Tests/ViewExecutableTest.php
+++ a/core/modules/views/lib/Drupal/views/Tests/ViewExecutableTest.php
@@ -85,7 +85,7 @@
     $this->installSchema('comment', array('comment', 'node_comment_statistics'));
     parent::setUpFixtures();
 
+    $this->installConfig(array('filter'));
-    $this->installConfig(array('system', 'filter'));
   }
 
   /**
only in patch2:
unchanged:
--- a/core/lib/Drupal/Core/Config/ConfigFactory.php
+++ b/core/lib/Drupal/Core/Config/ConfigFactory.php
@@ -93,15 +93,13 @@ public function get($name) {
    */
   public function reset($name = NULL) {
     if ($name) {
-      // Reinitialize the configuration object in all contexts.
+      // Clear the cached configuration object in all contexts.
       foreach ($this->getCacheKeys($name) as $cache_key) {
-        $this->cache[$cache_key]->init();
+        unset($this->cache[$cache_key]);
       }
     }
     else {
-      foreach ($this->cache as $config) {
-        $config->init();
-      }
+      $this->cache = array();
     }
     return $this;
   }
only in patch2:
unchanged:
--- a/core/modules/views/lib/Drupal/views/Tests/ViewUnitTestBase.php
+++ b/core/modules/views/lib/Drupal/views/Tests/ViewUnitTestBase.php
@@ -29,7 +29,7 @@
    *
    * @var array
    */
-  public static $modules = array('views', 'views_test_config', 'views_test_data');
+  public static $modules = array('system', 'views', 'views_test_config', 'views_test_data');
 
   protected function setUp() {
     parent::setUp();
@@ -62,6 +62,9 @@ protected function setUpFixtures() {
     }
     $query->execute();
 
+    // Tests implementing ViewUnitTestBase depend on the theme system being
+    // properly configured.
+    $this->installConfig(array('system'));
     ViewTestData::importTestViews(get_class($this), array('views_test_config'));
   }