diff --git a/core/includes/bootstrap.inc b/core/includes/bootstrap.inc
index 82ac9ef..d87b737 100644
--- a/core/includes/bootstrap.inc
+++ b/core/includes/bootstrap.inc
@@ -269,7 +269,7 @@ function drupal_get_filename($type, $name, $filename = NULL) {
  * the 'module://', 'profile://' and 'theme://' stream wrappers should be used
  * for other use cases.
  *
- * @param string $type 
+ * @param string $type
  *   The type of the item; one of 'core', 'profile', 'module', 'theme', or
  *   'theme_engine'.
  * @param $name
diff --git a/core/lib/Drupal/Core/StreamWrapper/LocalStream.php b/core/lib/Drupal/Core/StreamWrapper/LocalStream.php
index 9eafe5b..490abcd 100644
--- a/core/lib/Drupal/Core/StreamWrapper/LocalStream.php
+++ b/core/lib/Drupal/Core/StreamWrapper/LocalStream.php
@@ -62,14 +62,14 @@ public static function getType() {
   /**
    * Implements Drupal\Core\StreamWrapper\StreamWrapperInterface::setUri().
    */
-  function setUri($uri) {
+  public function setUri($uri) {
     $this->uri = $uri;
   }
 
   /**
    * Implements Drupal\Core\StreamWrapper\StreamWrapperInterface::getUri().
    */
-  function getUri() {
+  public function getUri() {
     return $this->uri;
   }
 
@@ -109,7 +109,7 @@ protected function getTarget($uri = NULL) {
   /**
    * Implements Drupal\Core\StreamWrapper\StreamWrapperInterface::realpath().
    */
-  function realpath() {
+  public function realpath() {
     return $this->getLocalPath();
   }
 
@@ -578,4 +578,5 @@ public function dir_closedir() {
     // have a return value.
     return TRUE;
   }
+
 }
diff --git a/core/lib/Drupal/Core/StreamWrapper/ModuleStream.php b/core/lib/Drupal/Core/StreamWrapper/ModuleStream.php
index bdfba2a..0a878a3 100644
--- a/core/lib/Drupal/Core/StreamWrapper/ModuleStream.php
+++ b/core/lib/Drupal/Core/StreamWrapper/ModuleStream.php
@@ -69,4 +69,5 @@ public function getName() {
   public function getDescription() {
     return t('Local module files.');
   }
+
 }
diff --git a/core/lib/Drupal/Core/StreamWrapper/ProfileStream.php b/core/lib/Drupal/Core/StreamWrapper/ProfileStream.php
index 0f10819..de03e6d 100644
--- a/core/lib/Drupal/Core/StreamWrapper/ProfileStream.php
+++ b/core/lib/Drupal/Core/StreamWrapper/ProfileStream.php
@@ -50,4 +50,5 @@ public function getName() {
   public function getDescription() {
     return t('Local profile files.');
   }
+
 }
diff --git a/core/lib/Drupal/Core/StreamWrapper/StreamWrapperInterface.php b/core/lib/Drupal/Core/StreamWrapper/StreamWrapperInterface.php
index 7c1c190..ea2297a 100644
--- a/core/lib/Drupal/Core/StreamWrapper/StreamWrapperInterface.php
+++ b/core/lib/Drupal/Core/StreamWrapper/StreamWrapperInterface.php
@@ -67,6 +67,7 @@
 
   /**
    * Not visible in the UI or accessible via web, but readable and writable.
+   *
    * E.g. the temporary directory for uploads.
    */
   const HIDDEN = 0x000C;
diff --git a/core/lib/Drupal/Core/StreamWrapper/ThemeStream.php b/core/lib/Drupal/Core/StreamWrapper/ThemeStream.php
index cf5ce38..a02b01a 100644
--- a/core/lib/Drupal/Core/StreamWrapper/ThemeStream.php
+++ b/core/lib/Drupal/Core/StreamWrapper/ThemeStream.php
@@ -77,12 +77,15 @@ protected function getOwnerName() {
       case 'current':
         $name = $this->getActiveTheme();
         break;
+
       case 'default':
         $name = $this->themeHandler->getDefault();
         break;
+
       case 'admin':
         $name = $this->configFactory->get('system.theme')->get('admin');
         break;
+
     }
     // Return name only for installed themes.
     if ($this->themeHandler->themeExists($name)) {
@@ -124,4 +127,5 @@ public function getName() {
   public function getDescription() {
     return t('Local theme files.');
   }
+
 }
diff --git a/core/modules/system/src/Tests/File/SystemStreamTest.php b/core/modules/system/src/Tests/File/SystemStreamTest.php
index 02b75ab..1f7d42f 100644
--- a/core/modules/system/src/Tests/File/SystemStreamTest.php
+++ b/core/modules/system/src/Tests/File/SystemStreamTest.php
@@ -7,7 +7,7 @@
 
 namespace Drupal\system\Tests\File;
 
-use Drupal\Component\Utility\String;
+use Drupal\Component\Utility\SafeMarkup;
 use Drupal\Core\Site\Settings;
 use Drupal\simpletest\KernelTestBase;
 
@@ -26,6 +26,13 @@ class SystemStreamTest extends KernelTestBase {
   public static $modules = array('system', 'file', 'file_test');
 
   /**
+   * The profile to install as a basis for testing.
+   *
+   * @var string
+   */
+  protected $profile = 'standard';
+
+  /**
    * {@inheritdoc}
    */
   public static function getInfo() {
@@ -44,9 +51,9 @@ public function setUp() {
     drupal_static_reset('file_get_stream_wrappers');
 
     // Add default profile for the purposes of this test.
-    new Settings(Settings::getAll() + array(
-      'install_profile' => 'standard'
-    ));
+//    new Settings(Settings::getAll() + array(
+//      'install_profile' => 'standard'
+//    ));
   }
 
   /**
@@ -67,16 +74,16 @@ public function testInvalidStreamUriException() {
     );
 
     /** @var \Drupal\Core\StreamWrapper\ModuleStream $instance */
-    $instance = file_stream_wrapper_get_instance_by_scheme('module');
+    $instance = \Drupal::service('stream_wrapper_manager')->getViaScheme('module');
 
     foreach ($bad_uris as $bad_uri) {
       try {
         $instance->dirname($bad_uri);
-        $this->fail(String::format('Invalid uri %uri not detected.', array('%uri' => $bad_uri)));
+        $this->fail(SafeMarkup::format('Invalid uri %uri not detected.', array('%uri' => $bad_uri)));
       }
       catch (\InvalidArgumentException $e) {
         if ($e->getMessage() == 'Malformed uri parameter passed: ' . $bad_uri) {
-          $this->pass(String::format('Throw exception on invalid uri %uri supplied.', array('%uri' => $bad_uri)));
+          $this->pass(SafeMarkup::format('Throw exception on invalid uri %uri supplied.', array('%uri' => $bad_uri)));
         }
         else {
           throw new \InvalidArgumentException($e);
@@ -91,7 +98,7 @@ public function testInvalidStreamUriException() {
   public function testModuleStream() {
     // Generate a module stream wrapper instance.
     /** @var \Drupal\Core\StreamWrapper\ModuleStream $instance */
-    $instance = file_stream_wrapper_get_instance_by_scheme('module');
+    $instance = \Drupal::service('stream_wrapper_manager')->getViaScheme('module');
 
     // dirname()
     $data = $this->providerModuleStream('dirname');
@@ -107,7 +114,7 @@ public function testModuleStream() {
   }
 
   /**
-   * Provides test data for testModuleStream()
+   * Provides test data for testModuleStream().
    */
   protected function providerModuleStream($method) {
     $uris = array(
@@ -159,7 +166,7 @@ protected function providerModuleStream($method) {
   public function testProfileStream() {
     // Generate a profile stream wrapper instance.
     /** @var \Drupal\Core\StreamWrapper\ProfileStream $instance */
-    $instance = file_stream_wrapper_get_instance_by_scheme('profile');
+    $instance = \Drupal::service('stream_wrapper_manager')->getViaScheme('profile');
 
     // dirname()
     $data = $this->providerProfileStream('dirname');
@@ -175,7 +182,7 @@ public function testProfileStream() {
   }
 
   /**
-   * Provides test data for testProfileStream()
+   * Provides test data for testProfileStream().
    */
   protected function providerProfileStream($method) {
     $uris = array(
@@ -194,8 +201,8 @@ protected function providerProfileStream($method) {
           array('profile://minimal/config/install', "Get the dirname of a resource located in a profile's subdirectory."),
           array('profile://minimal/config/install', "Get the dirname of a non-existent resource in profile's subdirectory."),
           array(new \InvalidArgumentException(), "Fail returning the dirname of a non-existent profile."),
-          array('profile://standard', String::format('Get the dirname of %current.', array('%current' => 'profile://current'))),
-          array('profile://standard', String::format('Get the dirname of a resource in %current path.', array('%current' => 'profile://current'))),
+          array('profile://standard', SafeMarkup::format('Get the dirname of %current.', array('%current' => 'profile://current'))),
+          array('profile://standard', SafeMarkup::format('Get the dirname of a resource in %current path.', array('%current' => 'profile://current'))),
         ));
 
       case 'realpath':
@@ -205,8 +212,8 @@ protected function providerProfileStream($method) {
           array($base_path . '/core/profiles/minimal/config/install/block.block.stark_login.yml', "Get the realpath of a resource located in a profile's subdirectory."),
           array($base_path . '/core/profiles/minimal/config/install/node.type.article.yml', "Get the realpath of a non-existent resource in profile's subdirectory."),
           array(new \InvalidArgumentException(), "Fail returning the realpath for a non-existent profile."),
-          array($base_path . '/core/profiles/standard', String::format('Get the realpath of %current.', array('%current' => 'profile://current'))),
-          array($base_path . '/core/profiles/standard/standard.info.yml', String::format('Get the realpath of a resource in %current path.', array('%current' => 'profile://current'))),
+          array($base_path . '/core/profiles/standard', SafeMarkup::format('Get the realpath of %current.', array('%current' => 'profile://current'))),
+          array($base_path . '/core/profiles/standard/standard.info.yml', SafeMarkup::format('Get the realpath of a resource in %current path.', array('%current' => 'profile://current'))),
         ));
 
       case 'getExternalUrl':
@@ -216,8 +223,8 @@ protected function providerProfileStream($method) {
           array($base_url . 'core/profiles/minimal/config/install/block.block.stark_login.yml', "Return the external url of a file located in a subdirectory."),
           array($base_url . 'core/profiles/minimal/config/install/node.type.article.yml', "Return the external url of a non-existent file located in a subdirectory."),
           array(new \InvalidArgumentException(), "Fail returning the external uri for a disabled profile."),
-          array($base_url . 'core/profiles/standard', String::format('Lookup the external url of %current for a partial URI.', array('%current' => 'profile://current'))),
-          array($base_url . 'core/profiles/standard/standard.info.yml', String::format('Lookup the external url of %current for a resource.', array('%current' => 'profile://current'))),
+          array($base_url . 'core/profiles/standard', SafeMarkup::format('Lookup the external url of %current for a partial URI.', array('%current' => 'profile://current'))),
+          array($base_url . 'core/profiles/standard/standard.info.yml', SafeMarkup::format('Lookup the external url of %current for a resource.', array('%current' => 'profile://current'))),
         ));
     }
   }
@@ -234,20 +241,20 @@ public function testThemeStream() {
     $theme_handler->install(array('bartik', 'seven', 'stark'));
 
     // Set admin theme to Seven.
-    $system_theme = \Drupal::config('system.theme');
+    $system_theme = \Drupal::configFactory()->getEditable('system.theme');
     $this->assertNull($system_theme->get('admin'), 'No admin theme was set.');
     $system_theme->set('admin', 'seven')->save();
-    $this->assertEqual($system_theme->get('admin'), 'seven', String::format('Make %seven the admin theme.', array('%seven' => 'Seven')));
+    $this->assertEqual($system_theme->get('admin'), 'seven', SafeMarkup::format('Make %seven the admin theme.', array('%seven' => 'Seven')));
 
     // Set default theme to Bartik.
     $theme_handler->setDefault('bartik');
-    $this->assertEqual($theme_handler->getDefault(), 'bartik', String::format('Make %bartik the default theme.', array('%bartik' => 'Bartik')));
+    $this->assertEqual($theme_handler->getDefault(), 'bartik', SafeMarkup::format('Make %bartik the default theme.', array('%bartik' => 'Bartik')));
 
     // Uninstall Stark theme.
     $theme_handler->uninstall(array('stark'));
 
     /** @var \Drupal\Core\StreamWrapper\ThemeStream $instance */
-    $instance = file_stream_wrapper_get_instance_by_scheme('theme');
+    $instance = \Drupal::service('stream_wrapper_manager')->getViaScheme('theme');
 
     // dirname()
     $data = $this->providerThemeStream('dirname');
@@ -287,12 +294,12 @@ protected function providerThemeStream($method) {
           array('theme://seven', "Get the dirname of a resource located in a theme directory."),
           array('theme://bartik/color', "Get the dirname of a resource located in a theme's subdirectory."),
           array(new \InvalidArgumentException(), "Fail returning the dirname of a non-existent theme."),
-          array('theme://bartik', String::format('Get the dirname of %current.', array('%current' => 'theme://current'))),
-          array('theme://bartik', String::format('Get the dirname of a resource in %current.', array('%current' => 'theme://current'))),
-          array('theme://bartik', String::format('Get the dirname of %default.', array('%default' => 'theme://default'))),
-          array('theme://bartik', String::format('Get the dirname of a resource in %default.', array('%default' => 'theme://default'))),
-          array('theme://seven', String::format('Get the dirname of %admin.', array('%admin' => 'theme://admin'))),
-          array('theme://seven', String::format('Get the dirname of a non-existent resource in %admin.', array('%admin' => 'theme://admin'))),
+          array('theme://bartik', SafeMarkup::format('Get the dirname of %current.', array('%current' => 'theme://current'))),
+          array('theme://bartik', SafeMarkup::format('Get the dirname of a resource in %current.', array('%current' => 'theme://current'))),
+          array('theme://bartik', SafeMarkup::format('Get the dirname of %default.', array('%default' => 'theme://default'))),
+          array('theme://bartik', SafeMarkup::format('Get the dirname of a resource in %default.', array('%default' => 'theme://default'))),
+          array('theme://seven', SafeMarkup::format('Get the dirname of %admin.', array('%admin' => 'theme://admin'))),
+          array('theme://seven', SafeMarkup::format('Get the dirname of a non-existent resource in %admin.', array('%admin' => 'theme://admin'))),
           array(new \InvalidArgumentException(), "Fail returning the dirname for an uninstalled theme."),
         ));
 
@@ -303,12 +310,12 @@ protected function providerThemeStream($method) {
           array($base_path . '/core/themes/seven/style.css', "Get the realpath of a resource located in a theme directory."),
           array($base_path . '/core/themes/bartik/color/preview.js', "Get the realpath of a resource located in a theme's subdirectory."),
           array(new \InvalidArgumentException(), "Fail returning the realpath of a non-existent theme."),
-          array($base_path . '/core/themes/bartik', String::format('Get the realpath of %current.', array('%current' => 'theme://current'))),
-          array($base_path . '/core/themes/bartik/logo.png', String::format('Get the realpath of a resource in %current.', array('%current' => 'theme://current'))),
-          array($base_path . '/core/themes/bartik', String::format('Get the realpath of %default.', array('%default' => 'theme://default'))),
-          array($base_path . '/core/themes/bartik/bartik.info.yml', String::format('Get the realpath of a resource in %default.', array('%default' => 'theme://default'))),
-          array($base_path . '/core/themes/seven', String::format('Get the realpath of %admin.', array('%admin' => 'theme://admin'))),
-          array($base_path . '/core/themes/seven/fake.info.yml', String::format('Get the realpath of a non-existent resource in %admin.', array('%admin' => 'theme://admin'))),
+          array($base_path . '/core/themes/bartik', SafeMarkup::format('Get the realpath of %current.', array('%current' => 'theme://current'))),
+          array($base_path . '/core/themes/bartik/logo.png', SafeMarkup::format('Get the realpath of a resource in %current.', array('%current' => 'theme://current'))),
+          array($base_path . '/core/themes/bartik', SafeMarkup::format('Get the realpath of %default.', array('%default' => 'theme://default'))),
+          array($base_path . '/core/themes/bartik/bartik.info.yml', SafeMarkup::format('Get the realpath of a resource in %default.', array('%default' => 'theme://default'))),
+          array($base_path . '/core/themes/seven', SafeMarkup::format('Get the realpath of %admin.', array('%admin' => 'theme://admin'))),
+          array($base_path . '/core/themes/seven/fake.info.yml', SafeMarkup::format('Get the realpath of a non-existent resource in %admin.', array('%admin' => 'theme://admin'))),
           array(new \InvalidArgumentException(), "Fail returning the realpath for an uninstalled theme."),
         ));
 
@@ -319,12 +326,12 @@ protected function providerThemeStream($method) {
           array($base_url . 'core/themes/seven/style.css', "Lookup theme's external url for a resource located in a subdirectory."),
           array($base_url . 'core/themes/bartik/color/preview.js', "Lookup theme's external url for a resource."),
           array(new \InvalidArgumentException(), "Fail returning a non-existent theme's external url."),
-          array($base_url . 'core/themes/bartik', String::format('Lookup real external url of %current for a partial URI.', array('%current' => 'theme://current'))),
-          array($base_url . 'core/themes/bartik/logo.png', String::format('Lookup external url of %current for a resource.', array('%current' => 'theme://current'))),
-          array($base_url . 'core/themes/bartik', String::format('Lookup external url of %default for a partial URI.', array('%default' => 'theme://default'))),
-          array($base_url . 'core/themes/bartik/bartik.info.yml', String::format('Lookup external url of %default for a resource.', array('%default' => 'theme://default'))),
-          array($base_url . 'core/themes/seven', String::format('Lookup external url of %admin for a partial URI.', array('%admin' => 'theme://admin'))),
-          array($base_url . 'core/themes/seven/fake.info.yml', String::format('Lookup external url of %admin for a resource.', array('%admin' => 'theme://admin'))),
+          array($base_url . 'core/themes/bartik', SafeMarkup::format('Lookup real external url of %current for a partial URI.', array('%current' => 'theme://current'))),
+          array($base_url . 'core/themes/bartik/logo.png', SafeMarkup::format('Lookup external url of %current for a resource.', array('%current' => 'theme://current'))),
+          array($base_url . 'core/themes/bartik', SafeMarkup::format('Lookup external url of %default for a partial URI.', array('%default' => 'theme://default'))),
+          array($base_url . 'core/themes/bartik/bartik.info.yml', SafeMarkup::format('Lookup external url of %default for a resource.', array('%default' => 'theme://default'))),
+          array($base_url . 'core/themes/seven', SafeMarkup::format('Lookup external url of %admin for a partial URI.', array('%admin' => 'theme://admin'))),
+          array($base_url . 'core/themes/seven/fake.info.yml', SafeMarkup::format('Lookup external url of %admin for a resource.', array('%admin' => 'theme://admin'))),
           array(new \InvalidArgumentException(), "Fail returning a disabled theme's external url."),
         ));
     }