diff --git a/core/includes/config.inc b/core/includes/config.inc
index 8e9ce5e..ddcc651 100644
--- a/core/includes/config.inc
+++ b/core/includes/config.inc
@@ -152,7 +152,7 @@ function config($name) {
  * config_context_leave() is called.
  *
  * @see config_context_leave()
- * @see \Drupal\Core\Config\ConfigFactory
+ * @see \Drupal\Core\Config\ConfigFactoryInterface
  *
  * @param string $context_name
  *   The name of the config context service on the container or a fully
@@ -183,7 +183,7 @@ function config_context_enter($context_name) {
  * Leaves the current config context returning to the previous context.
  *
  * @see config_context_enter()
- * @see \Drupal\Core\Config\ConfigFactory
+ * @see \Drupal\Core\Config\ConfigFactoryInterface
  */
 function config_context_leave() {
   drupal_container()
diff --git a/core/lib/Drupal/Core/Config/ConfigFactory.php b/core/lib/Drupal/Core/Config/ConfigFactory.php
index 60b3d0d..5f7ead4 100644
--- a/core/lib/Drupal/Core/Config/ConfigFactory.php
+++ b/core/lib/Drupal/Core/Config/ConfigFactory.php
@@ -28,7 +28,7 @@
  *
  * @see \Drupal\Core\Config\Context\ContextInterface
  */
-class ConfigFactory {
+class ConfigFactory implements ConfigFactoryInterface {
 
   /**
    * A storage controller instance for reading and writing configuration data.
@@ -65,13 +65,7 @@ public function __construct(StorageInterface $storage, ContextInterface $context
   }
 
   /**
-   * Returns a configuration object for a given name and context.
-   *
-   * @param string $name
-   *   The name of the configuration object to construct.
-   *
-   * @return \Drupal\Core\Config\Config
-   *   A configuration object.
+   * {@inheritdoc}
    */
   public function get($name) {
     $context = $this->getContext();
@@ -124,14 +118,7 @@ public function loadMultiple(array $names) {
   }
 
   /**
-   * Resets and re-initializes configuration objects. Internal use only.
-   *
-   * @param string $name
-   *   (optional) The name of the configuration object to reset. If omitted, all
-   *   configuration objects are reset.
-   *
-   * @return \Drupal\Core\Config\ConfigFactory
-   *   The config factory object.
+   * {@inheritdoc}
    */
   public function reset($name = NULL) {
     if ($name) {
@@ -152,15 +139,7 @@ public function reset($name = NULL) {
   }
 
   /**
-   * Renames a configuration object using the storage controller.
-   *
-   * @param string $old_name
-   *   The old name of the configuration object.
-   * @param string $new_name
-   *   The new name of the configuration object.
-   *
-   * @return \Drupal\Core\Config\Config
-   *   The renamed config object.
+   * {@inheritdoc}
    */
   public function rename($old_name, $new_name) {
     $context = $this->getContext();
@@ -181,13 +160,7 @@ public function rename($old_name, $new_name) {
   }
 
   /**
-   * Sets the config context by adding it to the context stack.
-   *
-   * @param \Drupal\Core\Config\Context\ContextInterface $context
-   *   The configuration context to add.
-   *
-   * @return \Drupal\Core\Config\ConfigFactory
-   *   The config factory object.
+   * {@inheritdoc}
    */
   public function enterContext(ContextInterface $context) {
     // Initialize the context as it is being entered.
@@ -196,20 +169,14 @@ public function enterContext(ContextInterface $context) {
   }
 
   /**
-   * Gets the current config context.
-   *
-   * @return \Drupal\Core\Config\Context\ContextInterface $context
-   *   The current configuration context.
+   * {@inheritdoc}
    */
   public function getContext() {
     return end($this->contextStack);
   }
 
   /**
-   * Leaves the current context by removing it from the context stack.
-   *
-   * @return \Drupal\Core\Config\ConfigFactory
-   *   The config factory object.
+   * {@inheritdoc}
    */
   public function leaveContext() {
     // Ensure at least one context is left on the stack. We already ensured
@@ -222,28 +189,14 @@ public function leaveContext() {
   }
 
   /**
-   * Gets the cache key for a given config name in a particular context.
-   *
-   * @param string $name
-   *   The name of the configuration object.
-   * @param \Drupal\Core\Config\Context\ContextInterface $context
-   *   The configuration context.
-   *
-   * @return string
-   *   The cache key.
+   * {@inheritdoc}
    */
   public function getCacheKey($name, ContextInterface $context) {
     return $name . ':' . $context->getUuid();
   }
 
   /**
-   * Gets all the cache keys that match the provided config name.
-   *
-   * @param string $name
-   *   The name of the configuration object.
-   *
-   * @return array
-   *   An array of cache keys that match the provided config name.
+   * {@inheritdoc}
    */
   public function getCacheKeys($name) {
     $cache_keys = array_keys($this->cache);
@@ -253,13 +206,11 @@ public function getCacheKeys($name) {
   }
 
   /**
-   * Clears the config factory static cache.
-   *
-   * @return \Drupal\Core\Config\ConfigFactory
-   *   The config factory object.
+   * {@inheritdoc}
    */
   public function clearStaticCache() {
     $this->cache = array();
     return $this;
   }
+
 }
diff --git a/core/lib/Drupal/Core/Config/ConfigFactoryInterface.php b/core/lib/Drupal/Core/Config/ConfigFactoryInterface.php
new file mode 100644
index 0000000..4a1b16d
--- /dev/null
+++ b/core/lib/Drupal/Core/Config/ConfigFactoryInterface.php
@@ -0,0 +1,112 @@
+<?php
+
+/**
+ * @file
+ * Contains \Drupal\Core\Config\ConfigFactoryInterface.
+ */
+
+namespace Drupal\Core\Config;
+
+use Drupal\Core\Config\Context\ContextInterface;
+
+/**
+ * Defines the interface for a configuration object factory.
+ */
+interface ConfigFactoryInterface {
+
+  /**
+   * Returns a configuration object for a given name and context.
+   *
+   * @param string $name
+   *   The name of the configuration object to construct.
+   *
+   * @return \Drupal\Core\Config\Config
+   *   A configuration object.
+   */
+  public function get($name);
+
+  /**
+   * Resets and re-initializes configuration objects. Internal use only.
+   *
+   * @param string $name
+   *   (optional) The name of the configuration object to reset. If omitted, all
+   *   configuration objects are reset.
+   *
+   * @return \Drupal\Core\Config\ConfigFactoryInterface
+   *   The config factory object.
+   */
+  public function reset($name = NULL);
+
+  /**
+   * Renames a configuration object using the storage controller.
+   *
+   * @param string $old_name
+   *   The old name of the configuration object.
+   * @param string $new_name
+   *   The new name of the configuration object.
+   *
+   * @return \Drupal\Core\Config\Config
+   *   The renamed config object.
+   */
+  public function rename($old_name, $new_name);
+
+  /**
+   * Sets the config context by adding it to the context stack.
+   *
+   * @param \Drupal\Core\Config\Context\ContextInterface $context
+   *   The configuration context to add.
+   *
+   * @return \Drupal\Core\Config\ConfigFactoryInterface
+   *   The config factory object.
+   */
+  public function enterContext(ContextInterface $context);
+
+  /**
+   * Gets the current config context.
+   *
+   * @return \Drupal\Core\Config\Context\ContextInterface $context
+   *   The current configuration context.
+   */
+  public function getContext();
+
+  /**
+   * Leaves the current context by removing it from the context stack.
+   *
+   * @return \Drupal\Core\Config\ConfigFactoryInterface
+   *   The config factory object.
+   */
+  public function leaveContext();
+
+  /**
+   * Gets the cache key for a given config name in a particular context.
+   *
+   * @param string $name
+   *   The name of the configuration object.
+   * @param \Drupal\Core\Config\Context\ContextInterface $context
+   *   The configuration context.
+   *
+   * @return string
+   *   The cache key.
+   */
+  public function getCacheKey($name, ContextInterface $context);
+
+  /**
+   * Gets all the cache keys that match the provided config name.
+   *
+   * @param string $name
+   *   The name of the configuration object.
+   *
+   * @return array
+   *   An array of cache keys that match the provided config name.
+   */
+  public function getCacheKeys($name);
+
+  /**
+   * Clears the config factory static cache.
+   *
+   * @return \Drupal\Core\Config\ConfigFactoryInterface
+   *   The config factory object.
+   */
+  public function clearStaticCache();
+
+}
diff --git a/core/lib/Drupal/Core/Config/ConfigImporter.php b/core/lib/Drupal/Core/Config/ConfigImporter.php
index f96d965..8321184 100644
--- a/core/lib/Drupal/Core/Config/ConfigImporter.php
+++ b/core/lib/Drupal/Core/Config/ConfigImporter.php
@@ -63,7 +63,7 @@ class ConfigImporter {
   /**
    * The configuration factory.
    *
-   * @var \Drupal\Core\Config\ConfigFactory
+   * @var \Drupal\Core\Config\ConfigFactoryInterface
    */
   protected $configFactory;
 
@@ -110,7 +110,7 @@ class ConfigImporter {
    *   access the source and target storage objects.
    * @param \Symfony\Component\EventDispatcher\EventDispatcherInterface $event_dispatcher
    *   The event dispatcher used to notify subscribers of config import events.
-   * @param \Drupal\Core\Config\ConfigFactory $config_factory
+   * @param \Drupal\Core\Config\ConfigFactoryInterface $config_factory
    *   The config factory that statically caches config objects.
    * @param \Drupal\Core\Entity\EntityManagerInterface $entity_manager
    *   The entity manager used to import config entities.
@@ -119,7 +119,7 @@ class ConfigImporter {
    * @param \Drupal\Component\Uuid\UuidInterface $uuid_service
    *   The UUID service.
    */
-  public function __construct(StorageComparerInterface $storage_comparer, EventDispatcherInterface $event_dispatcher, ConfigFactory $config_factory, EntityManagerInterface $entity_manager, LockBackendInterface $lock, UuidInterface $uuid_service) {
+  public function __construct(StorageComparerInterface $storage_comparer, EventDispatcherInterface $event_dispatcher, ConfigFactoryInterface $config_factory, EntityManagerInterface $entity_manager, LockBackendInterface $lock, UuidInterface $uuid_service) {
     $this->storageComparer = $storage_comparer;
     $this->eventDispatcher = $event_dispatcher;
     $this->configFactory = $config_factory;
diff --git a/core/lib/Drupal/Core/Config/Context/ContextInterface.php b/core/lib/Drupal/Core/Config/Context/ContextInterface.php
index e37d2d0..810c678 100644
--- a/core/lib/Drupal/Core/Config/Context/ContextInterface.php
+++ b/core/lib/Drupal/Core/Config/Context/ContextInterface.php
@@ -17,7 +17,7 @@
  * and contextual data to be used by configuration event listeners.
  *
  * @see \Drupal\Core\Config\Config
- * @see \Drupal\Core\Config\ConfigFactory
+ * @see \Drupal\Core\Config\ConfigFactoryInterface
  * @see \Drupal::config()
  */
 interface ContextInterface {
diff --git a/core/lib/Drupal/Core/Config/Entity/ConfigStorageController.php b/core/lib/Drupal/Core/Config/Entity/ConfigStorageController.php
index 30c1d7c..0bf60eb 100644
--- a/core/lib/Drupal/Core/Config/Entity/ConfigStorageController.php
+++ b/core/lib/Drupal/Core/Config/Entity/ConfigStorageController.php
@@ -11,7 +11,7 @@
 use Drupal\Core\Entity\EntityMalformedException;
 use Drupal\Core\Entity\EntityStorageControllerBase;
 use Drupal\Core\Config\Config;
-use Drupal\Core\Config\ConfigFactory;
+use Drupal\Core\Config\ConfigFactoryInterface;
 use Drupal\Core\Config\StorageInterface;
 use Drupal\Core\Entity\Query\QueryFactory;
 use Drupal\Component\Uuid\UuidInterface;
@@ -58,7 +58,7 @@ class ConfigStorageController extends EntityStorageControllerBase {
   /**
    * The config factory service.
    *
-   * @var \Drupal\Core\Config\ConfigFactory
+   * @var \Drupal\Core\Config\ConfigFactoryInterface
    */
   protected $configFactory;
 
@@ -83,7 +83,7 @@ class ConfigStorageController extends EntityStorageControllerBase {
    *   The entity type for which the instance is created.
    * @param array $entity_info
    *   An array of entity info for the entity type.
-   * @param \Drupal\Core\Config\ConfigFactory $config_factory
+   * @param \Drupal\Core\Config\ConfigFactoryInterface $config_factory
    *   The config factory service.
    * @param \Drupal\Core\Config\StorageInterface $config_storage
    *   The config storage service.
@@ -92,7 +92,7 @@ class ConfigStorageController extends EntityStorageControllerBase {
    * @param \Drupal\Component\Uuid\UuidInterface $uuid_service
    *   The UUID service.
    */
-  public function __construct($entity_type, array $entity_info, ConfigFactory $config_factory, StorageInterface $config_storage, QueryFactory $entity_query_factory, UuidInterface $uuid_service) {
+  public function __construct($entity_type, array $entity_info, ConfigFactoryInterface $config_factory, StorageInterface $config_storage, QueryFactory $entity_query_factory, UuidInterface $uuid_service) {
     parent::__construct($entity_type, $entity_info);
 
     $this->idKey = $this->entityInfo['entity_keys']['id'];
diff --git a/core/lib/Drupal/Core/Extension/ThemeHandler.php b/core/lib/Drupal/Core/Extension/ThemeHandler.php
index 40e59cb..1d34691 100644
--- a/core/lib/Drupal/Core/Extension/ThemeHandler.php
+++ b/core/lib/Drupal/Core/Extension/ThemeHandler.php
@@ -9,7 +9,7 @@
 
 use Drupal\Component\Utility\String;
 use Drupal\Core\Cache\CacheBackendInterface;
-use Drupal\Core\Config\ConfigFactory;
+use Drupal\Core\Config\ConfigFactoryInterface;
 use Drupal\Core\Routing\RouteBuilder;
 use Drupal\Core\SystemListingInfo;
 
@@ -45,7 +45,7 @@ class ThemeHandler implements ThemeHandlerInterface {
   /**
    * The config factory to get the enabled themes.
    *
-   * @var \Drupal\Core\Config\ConfigFactory
+   * @var \Drupal\Core\Config\ConfigFactoryInterface
    */
   protected $configFactory;
 
@@ -87,7 +87,7 @@ class ThemeHandler implements ThemeHandlerInterface {
   /**
    * Constructs a new ThemeHandler.
    *
-   * @param \Drupal\Core\Config\ConfigFactory $config_factory
+   * @param \Drupal\Core\Config\ConfigFactoryInterface $config_factory
    *   The config factory to get the enabled themes.
    * @param \Drupal\Core\Extension\ModuleHandlerInterface $module_handler
    *   The module handler to fire themes_enabled/themes_disabled hooks.
@@ -100,7 +100,7 @@ class ThemeHandler implements ThemeHandlerInterface {
    * @param \Drupal\Core\SystemListingInfo $system_list_info
    *   (optional) The system listing info.
    */
-  public function __construct(ConfigFactory $config_factory, ModuleHandlerInterface $module_handler, CacheBackendInterface $cache_backend, InfoParserInterface $info_parser, RouteBuilder $route_builder = NULL, SystemListingInfo $system_list_info = NULL) {
+  public function __construct(ConfigFactoryInterface $config_factory, ModuleHandlerInterface $module_handler, CacheBackendInterface $cache_backend, InfoParserInterface $info_parser, RouteBuilder $route_builder = NULL, SystemListingInfo $system_list_info = NULL) {
     $this->configFactory = $config_factory;
     $this->moduleHandler = $module_handler;
     $this->cacheBackend = $cache_backend;
diff --git a/core/lib/Drupal/Core/Form/ConfigFormBase.php b/core/lib/Drupal/Core/Form/ConfigFormBase.php
index 5c69835..422c02b 100644
--- a/core/lib/Drupal/Core/Form/ConfigFormBase.php
+++ b/core/lib/Drupal/Core/Form/ConfigFormBase.php
@@ -7,7 +7,7 @@
 
 namespace Drupal\Core\Form;
 
-use Drupal\Core\Config\ConfigFactory;
+use Drupal\Core\Config\ConfigFactoryInterface;
 use Drupal\Core\Config\Context\ContextInterface;
 use Drupal\Core\Form\FormBase;
 use Symfony\Component\DependencyInjection\ContainerInterface;
@@ -20,19 +20,19 @@
   /**
    * Stores the configuration factory.
    *
-   * @var \Drupal\Core\Config\ConfigFactory
+   * @var \Drupal\Core\Config\ConfigFactoryInterface
    */
   protected $configFactory;
 
   /**
    * Constructs a \Drupal\system\ConfigFormBase object.
    *
-   * @param \Drupal\Core\Config\ConfigFactory $config_factory
+   * @param \Drupal\Core\Config\ConfigFactoryInterface $config_factory
    *   The factory for configuration objects.
    * @param \Drupal\Core\Config\Context\ContextInterface $context
    *   The configuration context to use.
    */
-  public function __construct(ConfigFactory $config_factory, ContextInterface $context) {
+  public function __construct(ConfigFactoryInterface $config_factory, ContextInterface $context) {
     $this->configFactory = $config_factory;
     $this->configFactory->enterContext($context);
   }
diff --git a/core/lib/Drupal/Core/Form/FormBase.php b/core/lib/Drupal/Core/Form/FormBase.php
index 3dfd81c..bb34f18 100644
--- a/core/lib/Drupal/Core/Form/FormBase.php
+++ b/core/lib/Drupal/Core/Form/FormBase.php
@@ -7,7 +7,7 @@
 
 namespace Drupal\Core\Form;
 
-use Drupal\Core\Config\ConfigFactory;
+use Drupal\Core\Config\ConfigFactoryInterface;
 use Drupal\Core\DependencyInjection\ContainerInjectionInterface;
 use Drupal\Core\DependencyInjection\DependencySerialization;
 use Drupal\Core\Routing\UrlGeneratorInterface;
@@ -44,7 +44,7 @@
   /**
    * The config factory.
    *
-   * @var \Drupal\Core\Config\ConfigFactory
+   * @var \Drupal\Core\Config\ConfigFactoryInterface
    */
   protected $configFactory;
 
@@ -144,13 +144,13 @@ public function setTranslationManager(TranslationInterface $translation_manager)
   /**
    * Sets the config factory for this form.
    *
-   * @param \Drupal\Core\Config\ConfigFactory $config_factory
+   * @param \Drupal\Core\Config\ConfigFactoryInterface $config_factory
    *   The config factory.
    *
    * @return self
    *   The form.
    */
-  public function setConfigFactory(ConfigFactory $config_factory) {
+  public function setConfigFactory(ConfigFactoryInterface $config_factory) {
     $this->configFactory = $config_factory;
     return $this;
   }
diff --git a/core/lib/Drupal/Core/ImageToolkit/ImageToolkitManager.php b/core/lib/Drupal/Core/ImageToolkit/ImageToolkitManager.php
index 43686ff..eceab87 100644
--- a/core/lib/Drupal/Core/ImageToolkit/ImageToolkitManager.php
+++ b/core/lib/Drupal/Core/ImageToolkit/ImageToolkitManager.php
@@ -8,7 +8,7 @@
 namespace Drupal\Core\ImageToolkit;
 
 use Drupal\Core\Cache\CacheBackendInterface;
-use Drupal\Core\Config\ConfigFactory;
+use Drupal\Core\Config\ConfigFactoryInterface;
 use Drupal\Core\Language\LanguageManager;
 use Drupal\Core\Plugin\DefaultPluginManager;
 
@@ -20,7 +20,7 @@ class ImageToolkitManager extends DefaultPluginManager {
   /**
    * The config factory.
    *
-   * @var \Drupal\Core\Config\ConfigFactory
+   * @var \Drupal\Core\Config\ConfigFactoryInterface
    */
   protected $configFactory;
 
@@ -34,10 +34,10 @@ class ImageToolkitManager extends DefaultPluginManager {
    *   Cache backend instance to use.
    * @param \Drupal\Core\Language\LanguageManager $language_manager
    *   The language manager.
-   * @param \Drupal\Core\Config\ConfigFactory $config_factory
+   * @param \Drupal\Core\Config\ConfigFactoryInterface $config_factory
    *   The config factory.
    */
-  public function __construct(\Traversable $namespaces, CacheBackendInterface $cache_backend, LanguageManager $language_manager, ConfigFactory $config_factory) {
+  public function __construct(\Traversable $namespaces, CacheBackendInterface $cache_backend, LanguageManager $language_manager, ConfigFactoryInterface $config_factory) {
     parent::__construct('Plugin/ImageToolkit', $namespaces, 'Drupal\Core\ImageToolkit\Annotation\ImageToolkit');
 
     $this->setCacheBackend($cache_backend, $language_manager, 'image_toolkit_plugins');
diff --git a/core/lib/Drupal/Core/Mail/MailFactory.php b/core/lib/Drupal/Core/Mail/MailFactory.php
index d6bef9f..b69dc21 100644
--- a/core/lib/Drupal/Core/Mail/MailFactory.php
+++ b/core/lib/Drupal/Core/Mail/MailFactory.php
@@ -7,7 +7,7 @@
 
 namespace Drupal\Core\Mail;
 
-use Drupal\Core\Config\ConfigFactory;
+use Drupal\Core\Config\ConfigFactoryInterface;
 use Drupal\Component\Utility\String;
 
 /**
@@ -18,7 +18,7 @@ class MailFactory {
   /**
    * Config object for mail system configurations.
    *
-   * @var \Drupal\Core\Config\Config
+   * @var \Drupal\Core\Config\ConfigFactoryInterface
    */
   protected $mailConfig;
 
@@ -30,12 +30,12 @@ class MailFactory {
   protected $instances = array();
 
   /**
-   * Constructs a MailFActory object.
+   * Constructs a MailFactory object.
    *
-   * @param \Drupal\Core\Config\ConfigFactory $configFactory
+   * @param \Drupal\Core\Config\ConfigFactoryInterface $configFactory
    *   The configuration factory.
    */
-  public function __construct(ConfigFactory $configFactory) {
+  public function __construct(ConfigFactoryInterface $configFactory) {
     $this->mailConfig = $configFactory->get('system.mail');
   }
 
diff --git a/core/lib/Drupal/Core/PathProcessor/PathProcessorDecode.php b/core/lib/Drupal/Core/PathProcessor/PathProcessorDecode.php
index 0674cda..211ecd7 100644
--- a/core/lib/Drupal/Core/PathProcessor/PathProcessorDecode.php
+++ b/core/lib/Drupal/Core/PathProcessor/PathProcessorDecode.php
@@ -7,7 +7,7 @@
 
 namespace Drupal\Core\PathProcessor;
 
-use Drupal\Core\Config\ConfigFactory;
+use Drupal\Core\Config\ConfigFactoryInterface;
 use Symfony\Component\HttpFoundation\Request;
 
 /**
diff --git a/core/lib/Drupal/Core/PathProcessor/PathProcessorFront.php b/core/lib/Drupal/Core/PathProcessor/PathProcessorFront.php
index b5b3cd1..11c66fd 100644
--- a/core/lib/Drupal/Core/PathProcessor/PathProcessorFront.php
+++ b/core/lib/Drupal/Core/PathProcessor/PathProcessorFront.php
@@ -7,7 +7,7 @@
 
 namespace Drupal\Core\PathProcessor;
 
-use Drupal\Core\Config\ConfigFactory;
+use Drupal\Core\Config\ConfigFactoryInterface;
 use Symfony\Component\HttpFoundation\Request;
 
 /**
@@ -18,17 +18,17 @@ class PathProcessorFront implements InboundPathProcessorInterface, OutboundPathP
   /**
    * A config factory for retrieving required config settings.
    *
-   * @var \Drupal\Core\Config\ConfigFactory
+   * @var \Drupal\Core\Config\ConfigFactoryInterface
    */
   protected $config;
 
   /**
    * Constructs a PathProcessorFront object.
    *
-   * @param \Drupal\Core\Config\ConfigFactory $config
+   * @param \Drupal\Core\Config\ConfigFactoryInterface $config
    *   A config factory for retrieving the site front page configuration.
    */
-  public function __construct(ConfigFactory $config) {
+  public function __construct(ConfigFactoryInterface $config) {
     $this->config = $config;
   }
 
diff --git a/core/lib/Drupal/Core/Routing/UrlGenerator.php b/core/lib/Drupal/Core/Routing/UrlGenerator.php
index 1bb4b53..bcb174e 100644
--- a/core/lib/Drupal/Core/Routing/UrlGenerator.php
+++ b/core/lib/Drupal/Core/Routing/UrlGenerator.php
@@ -17,7 +17,7 @@
 
 use Drupal\Component\Utility\Settings;
 use Drupal\Component\Utility\Url;
-use Drupal\Core\Config\ConfigFactory;
+use Drupal\Core\Config\ConfigFactoryInterface;
 use Drupal\Core\PathProcessor\OutboundPathProcessorInterface;
 use Drupal\Core\RouteProcessor\OutboundRouteProcessorInterface;
 
@@ -85,7 +85,7 @@ class UrlGenerator extends ProviderBasedGenerator implements UrlGeneratorInterfa
    * @param \Symfony\Component\HttpKernel\Log\LoggerInterface $logger
    *   An optional logger for recording errors.
    */
-  public function __construct(RouteProviderInterface $provider, OutboundPathProcessorInterface $path_processor, OutboundRouteProcessorInterface $route_processor, ConfigFactory $config, Settings $settings, LoggerInterface $logger = NULL) {
+  public function __construct(RouteProviderInterface $provider, OutboundPathProcessorInterface $path_processor, OutboundRouteProcessorInterface $route_processor, ConfigFactoryInterface $config, Settings $settings, LoggerInterface $logger = NULL) {
     parent::__construct($provider, $logger);
 
     $this->pathProcessor = $path_processor;
diff --git a/core/modules/aggregator/lib/Drupal/aggregator/Form/SettingsForm.php b/core/modules/aggregator/lib/Drupal/aggregator/Form/SettingsForm.php
index 1c59201..f9e18dd 100644
--- a/core/modules/aggregator/lib/Drupal/aggregator/Form/SettingsForm.php
+++ b/core/modules/aggregator/lib/Drupal/aggregator/Form/SettingsForm.php
@@ -10,7 +10,7 @@
 use Drupal\aggregator\Plugin\AggregatorPluginManager;
 use Drupal\Component\Utility\String;
 use Drupal\Core\Config\Context\ContextInterface;
-use Drupal\Core\Config\ConfigFactory;
+use Drupal\Core\Config\ConfigFactoryInterface;
 use Drupal\Core\Plugin\PluginFormInterface;
 use Drupal\Core\StringTranslation\TranslationInterface;
 use Drupal\Core\Form\ConfigFormBase;
@@ -49,7 +49,7 @@ class SettingsForm extends ConfigFormBase {
   /**
    * Constructs a \Drupal\aggregator\SettingsForm object.
    *
-   * @param \Drupal\Core\Config\ConfigFactory $config_factory
+   * @param \Drupal\Core\Config\ConfigFactoryInterface $config_factory
    *   The factory for configuration objects.
    * @param \Drupal\Core\Config\Context\ContextInterface $context
    *   The configuration context to use.
@@ -62,7 +62,7 @@ class SettingsForm extends ConfigFormBase {
    * @param \Drupal\Core\StringTranslation\TranslationInterface $translation_manager
    *   The string translation manager.
    */
-  public function __construct(ConfigFactory $config_factory, ContextInterface $context, AggregatorPluginManager $fetcher_manager, AggregatorPluginManager $parser_manager, AggregatorPluginManager $processor_manager, TranslationInterface $translation_manager) {
+  public function __construct(ConfigFactoryInterface $config_factory, ContextInterface $context, AggregatorPluginManager $fetcher_manager, AggregatorPluginManager $parser_manager, AggregatorPluginManager $processor_manager, TranslationInterface $translation_manager) {
     parent::__construct($config_factory, $context);
     $this->translationManager = $translation_manager;
     $this->managers = array(
diff --git a/core/modules/aggregator/lib/Drupal/aggregator/Plugin/aggregator/processor/DefaultProcessor.php b/core/modules/aggregator/lib/Drupal/aggregator/Plugin/aggregator/processor/DefaultProcessor.php
index 85b7217..e589031 100644
--- a/core/modules/aggregator/lib/Drupal/aggregator/Plugin/aggregator/processor/DefaultProcessor.php
+++ b/core/modules/aggregator/lib/Drupal/aggregator/Plugin/aggregator/processor/DefaultProcessor.php
@@ -13,7 +13,7 @@
 use Drupal\aggregator\Entity\Feed;
 use Drupal\Core\Annotation\Translation;
 use Drupal\Core\Database\Database;
-use Drupal\Core\Config\ConfigFactory;
+use Drupal\Core\Config\ConfigFactoryInterface;
 use Drupal\Core\Plugin\ContainerFactoryPluginInterface;
 use Symfony\Component\DependencyInjection\ContainerInterface;
 
@@ -33,7 +33,7 @@ class DefaultProcessor extends AggregatorPluginSettingsBase implements Processor
   /**
    * Contains the configuration object factory.
    *
-   * @var \Drupal\Core\Config\ConfigFactory
+   * @var \Drupal\Core\Config\ConfigFactoryInterface
    */
   protected $configFactory;
 
@@ -46,10 +46,10 @@ class DefaultProcessor extends AggregatorPluginSettingsBase implements Processor
    *   The plugin_id for the plugin instance.
    * @param array $plugin_definition
    *   The plugin implementation definition.
-   * @param \Drupal\Core\Config\ConfigFactory $config
+   * @param \Drupal\Core\Config\ConfigFactoryInterface $config
    *   The configuration factory object.
    */
-  public function __construct(array $configuration, $plugin_id, array $plugin_definition, ConfigFactory $config) {
+  public function __construct(array $configuration, $plugin_id, array $plugin_definition, ConfigFactoryInterface $config) {
     $this->configFactory = $config;
     // @todo Refactor aggregator plugins to ConfigEntity so merging
     //   the configuration here is not needed.
diff --git a/core/modules/aggregator/tests/modules/aggregator_test/lib/Drupal/aggregator_test/Plugin/aggregator/processor/TestProcessor.php b/core/modules/aggregator/tests/modules/aggregator_test/lib/Drupal/aggregator_test/Plugin/aggregator/processor/TestProcessor.php
index 04a5c5a..d77f59a 100644
--- a/core/modules/aggregator/tests/modules/aggregator_test/lib/Drupal/aggregator_test/Plugin/aggregator/processor/TestProcessor.php
+++ b/core/modules/aggregator/tests/modules/aggregator_test/lib/Drupal/aggregator_test/Plugin/aggregator/processor/TestProcessor.php
@@ -12,7 +12,7 @@
 use Drupal\aggregator\Entity\Feed;
 use Drupal\aggregator\Annotation\AggregatorProcessor;
 use Drupal\Core\Annotation\Translation;
-use Drupal\Core\Config\ConfigFactory;
+use Drupal\Core\Config\ConfigFactoryInterface;
 use Drupal\Core\Plugin\ContainerFactoryPluginInterface;
 use Symfony\Component\DependencyInjection\ContainerInterface;
 
@@ -32,7 +32,7 @@ class TestProcessor extends AggregatorPluginSettingsBase implements ProcessorInt
   /**
    * Contains the configuration object factory.
    *
-   * @var \Drupal\Core\Config\ConfigFactory
+   * @var \Drupal\Core\Config\ConfigFactoryInterface
    */
   protected $configFactory;
 
@@ -57,10 +57,10 @@ public static function create(ContainerInterface $container, array $configuratio
    *   The plugin_id for the plugin instance.
    * @param array $plugin_definition
    *   The plugin implementation definition.
-   * @param \Drupal\Core\Config\ConfigFactory $config
+   * @param \Drupal\Core\Config\ConfigFactoryInterface $config
    *   The configuration factory object.
    */
-  public function __construct(array $configuration, $plugin_id, array $plugin_definition, ConfigFactory $config) {
+  public function __construct(array $configuration, $plugin_id, array $plugin_definition, ConfigFactoryInterface $config) {
     $this->configFactory = $config;
     parent::__construct($configuration + $this->getConfiguration(), $plugin_id, $plugin_definition);
   }
diff --git a/core/modules/basic_auth/lib/Drupal/basic_auth/Authentication/Provider/BasicAuth.php b/core/modules/basic_auth/lib/Drupal/basic_auth/Authentication/Provider/BasicAuth.php
index 573da4c..79fe59f 100644
--- a/core/modules/basic_auth/lib/Drupal/basic_auth/Authentication/Provider/BasicAuth.php
+++ b/core/modules/basic_auth/lib/Drupal/basic_auth/Authentication/Provider/BasicAuth.php
@@ -10,7 +10,7 @@
 use \Drupal\Component\Utility\String;
 use Drupal\Core\Authentication\AuthenticationProviderInterface;
 use Drupal\Core\Config\Config;
-use Drupal\Core\Config\ConfigFactory;
+use Drupal\Core\Config\ConfigFactoryInterface;
 use Symfony\Component\HttpFoundation\Request;
 use Symfony\Component\HttpKernel\Event\GetResponseForExceptionEvent;
 use Symfony\Component\HttpKernel\Exception\UnauthorizedHttpException;
@@ -24,17 +24,17 @@ class BasicAuth implements AuthenticationProviderInterface {
   /**
    * The config factory.
    *
-   * @var \Drupal\Core\Config\ConfigFactory
+   * @var \Drupal\Core\Config\ConfigFactoryInterface
    */
   protected $configFactory;
 
   /**
    * Constructs a HTTP basic authentication provider object.
    *
-   * @param \Drupal\Core\Config\ConfigFactory $config_factory
+   * @param \Drupal\Core\Config\ConfigFactoryInterface $config_factory
    *   The config factory.
    */
-  public function __construct(ConfigFactory $config_factory) {
+  public function __construct(ConfigFactoryInterface $config_factory) {
     $this->configFactory = $config_factory;
   }
 
diff --git a/core/modules/block/lib/Drupal/block/BlockFormController.php b/core/modules/block/lib/Drupal/block/BlockFormController.php
index 5965c21..5189a37 100644
--- a/core/modules/block/lib/Drupal/block/BlockFormController.php
+++ b/core/modules/block/lib/Drupal/block/BlockFormController.php
@@ -8,7 +8,7 @@
 namespace Drupal\block;
 
 use Drupal\Core\Cache\Cache;
-use Drupal\Core\Config\ConfigFactory;
+use Drupal\Core\Config\ConfigFactoryInterface;
 use Drupal\Core\Entity\EntityFormController;
 use Drupal\Core\Entity\EntityManagerInterface;
 use Drupal\Core\Entity\Query\QueryFactory;
@@ -52,7 +52,7 @@ class BlockFormController extends EntityFormController {
   /**
    * The config factory.
    *
-   * @var \Drupal\Core\Config\ConfigFactory
+   * @var \Drupal\Core\Config\ConfigFactoryInterface
    */
   protected $configFactory;
 
@@ -65,10 +65,10 @@ class BlockFormController extends EntityFormController {
    *   The entity query factory.
    * @param \Drupal\Core\Language\LanguageManager $language_manager
    *   The language manager.
-   * @param \Drupal\Core\Config\ConfigFactory $config_factory
+   * @param \Drupal\Core\Config\ConfigFactoryInterface $config_factory
    *   The config factory.
    */
-  public function __construct(EntityManagerInterface $entity_manager, QueryFactory $entity_query_factory, LanguageManager $language_manager, ConfigFactory $config_factory) {
+  public function __construct(EntityManagerInterface $entity_manager, QueryFactory $entity_query_factory, LanguageManager $language_manager, ConfigFactoryInterface $config_factory) {
     $this->storageController = $entity_manager->getStorageController('block');
     $this->entityQueryFactory = $entity_query_factory;
     $this->languageManager = $language_manager;
diff --git a/core/modules/block/lib/Drupal/block/Plugin/Derivative/ThemeLocalTask.php b/core/modules/block/lib/Drupal/block/Plugin/Derivative/ThemeLocalTask.php
index 77a2235..540cf7b 100644
--- a/core/modules/block/lib/Drupal/block/Plugin/Derivative/ThemeLocalTask.php
+++ b/core/modules/block/lib/Drupal/block/Plugin/Derivative/ThemeLocalTask.php
@@ -8,7 +8,7 @@
 namespace Drupal\block\Plugin\Derivative;
 
 use Drupal\Component\Plugin\Derivative\DerivativeBase;
-use Drupal\Core\Config\ConfigFactory;
+use Drupal\Core\Config\ConfigFactoryInterface;
 use Drupal\Core\Plugin\Discovery\ContainerDerivativeInterface;
 use Symfony\Component\DependencyInjection\ContainerInterface;
 
@@ -20,17 +20,17 @@ class ThemeLocalTask extends DerivativeBase implements ContainerDerivativeInterf
   /**
    * Stores the theme settings config object.
    *
-   * @var \Drupal\Core\Config\Config
+   * @var \Drupal\Core\Config\ConfigFactoryInterface
    */
   protected $config;
 
   /**
    * Constructs a new ThemeLocalTask.
    *
-   * @param \Drupal\Core\Config\ConfigFactory $config_factory
+   * @param \Drupal\Core\Config\ConfigFactoryInterface ConfigFactoryInterface
    *   The config factory.
    */
-  public function __construct(ConfigFactory $config_factory) {
+  public function __construct(ConfigFactoryInterface $config_factory) {
     $this->config = $config_factory->get('system.theme');
   }
 
diff --git a/core/modules/block/tests/Drupal/block/Tests/BlockFormControllerTest.php b/core/modules/block/tests/Drupal/block/Tests/BlockFormControllerTest.php
index 69b0a1b..4f8a47c 100644
--- a/core/modules/block/tests/Drupal/block/Tests/BlockFormControllerTest.php
+++ b/core/modules/block/tests/Drupal/block/Tests/BlockFormControllerTest.php
@@ -70,7 +70,7 @@ public function testGetUniqueMachineName() {
       ->disableOriginalConstructor()
       ->getMock();
 
-    $config_factory = $this->getMockBuilder('Drupal\Core\Config\ConfigFactory')
+    $config_factory = $this->getMockBuilder('Drupal\Core\Config\ConfigFactoryInterface')
       ->disableOriginalConstructor()
       ->getMock();
 
diff --git a/core/modules/book/lib/Drupal/book/BookManager.php b/core/modules/book/lib/Drupal/book/BookManager.php
index 9b415a8..9f8522f 100644
--- a/core/modules/book/lib/Drupal/book/BookManager.php
+++ b/core/modules/book/lib/Drupal/book/BookManager.php
@@ -13,7 +13,7 @@
 use Drupal\Core\Language\Language;
 use Drupal\Core\Session\AccountInterface;
 use Drupal\Core\StringTranslation\TranslationInterface;
-use Drupal\Core\Config\ConfigFactory;
+use Drupal\Core\Config\ConfigFactoryInterface;
 use Drupal\node\NodeInterface;
 
 /**
@@ -45,7 +45,7 @@ class BookManager {
   /**
    * Config Factory Service Object.
    *
-   * @var \Drupal\Core\Config\ConfigFactory
+   * @var \Drupal\Core\Config\ConfigFactoryInterface
    */
   protected $configFactory;
 
@@ -59,7 +59,7 @@ class BookManager {
   /**
    * Constructs a BookManager object.
    */
-  public function __construct(Connection $connection, EntityManagerInterface $entity_manager, TranslationInterface $translation, ConfigFactory $config_factory) {
+  public function __construct(Connection $connection, EntityManagerInterface $entity_manager, TranslationInterface $translation, ConfigFactoryInterface $config_factory) {
     $this->connection = $connection;
     $this->entityManager = $entity_manager;
     $this->translation =  $translation;
diff --git a/core/modules/config/lib/Drupal/config/Form/ConfigSync.php b/core/modules/config/lib/Drupal/config/Form/ConfigSync.php
index 5654d45..59d9f0f 100644
--- a/core/modules/config/lib/Drupal/config/Form/ConfigSync.php
+++ b/core/modules/config/lib/Drupal/config/Form/ConfigSync.php
@@ -15,7 +15,7 @@
 use Drupal\Core\Config\StorageComparer;
 use Drupal\Core\Config\ConfigImporter;
 use Drupal\Core\Config\ConfigException;
-use Drupal\Core\Config\ConfigFactory;
+use Drupal\Core\Config\ConfigFactoryInterface;
 use Drupal\Core\Routing\UrlGeneratorInterface;
 use Symfony\Component\EventDispatcher\EventDispatcherInterface;
 use Symfony\Component\DependencyInjection\ContainerInterface;
@@ -83,7 +83,7 @@ class ConfigSync extends FormBase {
    *   The lock object.
    * @param \Symfony\Component\EventDispatcher\EventDispatcherInterface $event_dispatcher
    *   Event dispatcher.
-   * @param \Drupal\Core\Config\ConfigFactory $config_factory
+   * @param \Drupal\Core\Config\ConfigFactoryInterface $config_factory
    *   The config factory.
    * @param \Drupal\Core\Entity\EntityManagerInterface $entity_manager
    *   Entity manager.
@@ -92,7 +92,7 @@ class ConfigSync extends FormBase {
    * @param \Drupal\Component\Uuid\UuidInterface $uuid_service
    * The UUID Service.
    */
-  public function __construct(StorageInterface $sourceStorage, StorageInterface $targetStorage, LockBackendInterface $lock, EventDispatcherInterface $event_dispatcher, ConfigFactory $config_factory, EntityManagerInterface $entity_manager, UrlGeneratorInterface $url_generator, UuidInterface $uuid_service) {
+  public function __construct(StorageInterface $sourceStorage, StorageInterface $targetStorage, LockBackendInterface $lock, EventDispatcherInterface $event_dispatcher, ConfigFactoryInterface $config_factory, EntityManagerInterface $entity_manager, UrlGeneratorInterface $url_generator, UuidInterface $uuid_service) {
     $this->sourceStorage = $sourceStorage;
     $this->targetStorage = $targetStorage;
     $this->lock = $lock;
diff --git a/core/modules/config_translation/lib/Drupal/config_translation/ConfigEntityMapper.php b/core/modules/config_translation/lib/Drupal/config_translation/ConfigEntityMapper.php
index 44e0d7f..15a5049 100644
--- a/core/modules/config_translation/lib/Drupal/config_translation/ConfigEntityMapper.php
+++ b/core/modules/config_translation/lib/Drupal/config_translation/ConfigEntityMapper.php
@@ -8,7 +8,7 @@
 namespace Drupal\config_translation;
 
 use Drupal\Component\Utility\Unicode;
-use Drupal\Core\Config\ConfigFactory;
+use Drupal\Core\Config\ConfigFactoryInterface;
 use Drupal\Core\Entity\EntityInterface;
 use Drupal\Core\Entity\EntityManager;
 use Drupal\Core\Routing\RouteProviderInterface;
@@ -59,7 +59,7 @@ class ConfigEntityMapper extends ConfigNamesMapper {
    *   An array of plugin information as documented in
    *   ConfigNamesMapper::__construct() with the following additional keys:
    *   - entity_type: The name of the entity type this mapper belongs to.
-   * @param \Drupal\Core\Config\ConfigFactory $config_factory
+   * @param \Drupal\Core\Config\ConfigFactoryInterface $config_factory
    *   The configuration factory.
    * @param \Drupal\locale\LocaleConfigManager $locale_config_manager
    *   The locale configuration manager.
@@ -72,7 +72,7 @@ class ConfigEntityMapper extends ConfigNamesMapper {
    * @param \Drupal\Core\Entity\EntityManager $entity_manager
    *   The entity manager.
    */
-  public function __construct($plugin_id, array $plugin_definition, ConfigFactory $config_factory, LocaleConfigManager $locale_config_manager, ConfigMapperManagerInterface $config_mapper_manager, RouteProviderInterface $route_provider, TranslationInterface $translation_manager, EntityManager $entity_manager) {
+  public function __construct($plugin_id, array $plugin_definition, ConfigFactoryInterface $config_factory, LocaleConfigManager $locale_config_manager, ConfigMapperManagerInterface $config_mapper_manager, RouteProviderInterface $route_provider, TranslationInterface $translation_manager, EntityManager $entity_manager) {
     parent::__construct($plugin_id, $plugin_definition, $config_factory, $locale_config_manager, $config_mapper_manager, $route_provider, $translation_manager);
     $this->setType($plugin_definition['entity_type']);
 
diff --git a/core/modules/config_translation/lib/Drupal/config_translation/ConfigNamesMapper.php b/core/modules/config_translation/lib/Drupal/config_translation/ConfigNamesMapper.php
index 2df7387..6398930 100644
--- a/core/modules/config_translation/lib/Drupal/config_translation/ConfigNamesMapper.php
+++ b/core/modules/config_translation/lib/Drupal/config_translation/ConfigNamesMapper.php
@@ -7,7 +7,7 @@
 
 namespace Drupal\config_translation;
 
-use Drupal\Core\Config\ConfigFactory;
+use Drupal\Core\Config\ConfigFactoryInterface;
 use Drupal\Core\Language\Language;
 use Drupal\Core\Plugin\PluginBase;
 use Drupal\Core\Routing\RouteProviderInterface;
@@ -26,7 +26,7 @@ class ConfigNamesMapper extends PluginBase implements ConfigMapperInterface, Con
   /**
    * The configuration factory.
    *
-   * @var \Drupal\Core\Config\ConfigFactory
+   * @var \Drupal\Core\Config\ConfigFactoryInterface
    */
   protected $configFactory;
 
@@ -73,7 +73,7 @@ class ConfigNamesMapper extends PluginBase implements ConfigMapperInterface, Con
    *     Defaults to 20.
    *   - list_controller: (optional) Class name for list controller used to
    *     generate lists of this type of configuration.
-   * @param \Drupal\Core\Config\ConfigFactory $config_factory
+   * @param \Drupal\Core\Config\ConfigFactoryInterface $config_factory
    *   The configuration factory.
    * @param \Drupal\locale\LocaleConfigManager $locale_config_manager
    *   The locale configuration manager.
@@ -88,7 +88,7 @@ class ConfigNamesMapper extends PluginBase implements ConfigMapperInterface, Con
    *   Throws an exception if the route specified by the 'base_route_name' in
    *   the plugin definition could not be found by the route provider.
    */
-  public function __construct($plugin_id, array $plugin_definition, ConfigFactory $config_factory, LocaleConfigManager $locale_config_manager, ConfigMapperManagerInterface $config_mapper_manager, RouteProviderInterface $route_provider, TranslationInterface $translation_manager) {
+  public function __construct($plugin_id, array $plugin_definition, ConfigFactoryInterface $config_factory, LocaleConfigManager $locale_config_manager, ConfigMapperManagerInterface $config_mapper_manager, RouteProviderInterface $route_provider, TranslationInterface $translation_manager) {
     $this->pluginId = $plugin_id;
     $this->pluginDefinition = $plugin_definition;
 
diff --git a/core/modules/config_translation/tests/Drupal/config_translation/Tests/ConfigNamesMapperTest.php b/core/modules/config_translation/tests/Drupal/config_translation/Tests/ConfigNamesMapperTest.php
index 3df6ac0..7746a22 100644
--- a/core/modules/config_translation/tests/Drupal/config_translation/Tests/ConfigNamesMapperTest.php
+++ b/core/modules/config_translation/tests/Drupal/config_translation/Tests/ConfigNamesMapperTest.php
@@ -8,7 +8,7 @@
 namespace Drupal\config_translation\Tests;
 
 use Drupal\config_translation\ConfigNamesMapper;
-use Drupal\Core\Config\ConfigFactory;
+use Drupal\Core\Config\ConfigFactoryInterface;
 use Drupal\Core\Language\Language;
 use Drupal\Tests\UnitTestCase;
 use Symfony\Component\Routing\Route;
@@ -646,10 +646,10 @@ public function setConfigNames(array $config_names) {
   /**
    * Sets the configuration factory.
    *
-   * @var \Drupal\Core\Config\ConfigFactory $config_factory
+   * @var \Drupal\Core\Config\ConfigFactoryInterface $config_factory
    *   The config factory to set.
    */
-  public function setConfigFactory(ConfigFactory $config_factory) {
+  public function setConfigFactory(ConfigFactoryInterface $config_factory) {
     $this->configFactory = $config_factory;
   }
 
diff --git a/core/modules/contact/lib/Drupal/contact/Access/ContactPageAccess.php b/core/modules/contact/lib/Drupal/contact/Access/ContactPageAccess.php
index 182cc1a..3df8129 100644
--- a/core/modules/contact/lib/Drupal/contact/Access/ContactPageAccess.php
+++ b/core/modules/contact/lib/Drupal/contact/Access/ContactPageAccess.php
@@ -8,7 +8,7 @@
 namespace Drupal\contact\Access;
 
 use Drupal\Core\Access\StaticAccessCheckInterface;
-use Drupal\Core\Config\ConfigFactory;
+use Drupal\Core\Config\ConfigFactoryInterface;
 use Drupal\Core\Session\AccountInterface;
 use Drupal\user\UserDataInterface;
 use Symfony\Component\Routing\Route;
@@ -22,7 +22,7 @@ class ContactPageAccess implements StaticAccessCheckInterface {
   /**
    * The contact settings config object.
    *
-   * @var \Drupal\Core\Config\ConfigFactory
+   * @var \Drupal\Core\Config\ConfigFactoryInterface
    */
   protected $configFactory;
 
@@ -36,12 +36,12 @@ class ContactPageAccess implements StaticAccessCheckInterface {
   /**
    * Constructs a ContactPageAccess instance.
    *
-   * @param \Drupal\Core\Config\ConfigFactory $config_factory
+   * @param \Drupal\Core\Config\ConfigFactoryInterface $config_factory
    *   The config factory.
    * @param \Drupal\user\UserDataInterface $user_data
    *   The user data service.
    */
-  public function __construct(ConfigFactory $config_factory, UserDataInterface $user_data) {
+  public function __construct(ConfigFactoryInterface $config_factory, UserDataInterface $user_data) {
     $this->configFactory = $config_factory;
     $this->userData = $user_data;
   }
diff --git a/core/modules/field/lib/Drupal/field/FieldInfo.php b/core/modules/field/lib/Drupal/field/FieldInfo.php
index 7abc9db..dfa0156 100644
--- a/core/modules/field/lib/Drupal/field/FieldInfo.php
+++ b/core/modules/field/lib/Drupal/field/FieldInfo.php
@@ -8,7 +8,7 @@
 namespace Drupal\field;
 
 use Drupal\Core\Cache\CacheBackendInterface;
-use Drupal\Core\Config\ConfigFactory;
+use Drupal\Core\Config\ConfigFactoryInterface;
 use Drupal\Core\Field\FieldTypePluginManager;
 use Drupal\Core\Extension\ModuleHandlerInterface;
 use Drupal\field\FieldInterface;
@@ -57,7 +57,7 @@ class FieldInfo {
   /**
    * The config factory.
    *
-   * @var \Drupal\Core\Config\ConfigFactory
+   * @var \Drupal\Core\Config\ConfigFactoryInterface
    */
   protected $config;
 
@@ -129,14 +129,14 @@ class FieldInfo {
    *
    * @param \Drupal\Core\Cache\CacheBackendInterface $cache_backend
    *   The cache backend to use.
-   * @param \Drupal\Core\Config\ConfigFactory $config
+   * @param \Drupal\Core\Config\ConfigFactoryInterface $config
    *   The configuration factory object to use.
    * @param \Drupal\Core\Extension\ModuleHandlerInterface $module_handler
    *   The module handler class to use for invoking hooks.
    * @param \Drupal\Core\Field\FieldTypePluginManager $field_type_manager
    *   The 'field type' plugin manager.
    */
-  public function __construct(CacheBackendInterface $cache_backend, ConfigFactory $config, ModuleHandlerInterface $module_handler, FieldTypePluginManager $field_type_manager) {
+  public function __construct(CacheBackendInterface $cache_backend, ConfigFactoryInterface $config, ModuleHandlerInterface $module_handler, FieldTypePluginManager $field_type_manager) {
     $this->cacheBackend = $cache_backend;
     $this->moduleHandler = $module_handler;
     $this->config = $config;
diff --git a/core/modules/field/lib/Drupal/field/FieldInstanceStorageController.php b/core/modules/field/lib/Drupal/field/FieldInstanceStorageController.php
index 3e69ae6..1b91def 100644
--- a/core/modules/field/lib/Drupal/field/FieldInstanceStorageController.php
+++ b/core/modules/field/lib/Drupal/field/FieldInstanceStorageController.php
@@ -12,7 +12,7 @@
 use Drupal\Core\Entity\EntityManagerInterface;
 use Drupal\Core\Entity\Query\QueryFactory;
 use Symfony\Component\DependencyInjection\ContainerInterface;
-use Drupal\Core\Config\ConfigFactory;
+use Drupal\Core\Config\ConfigFactoryInterface;
 use Drupal\Component\Uuid\UuidInterface;
 use Drupal\Core\Config\StorageInterface;
 use Drupal\Core\Extension\ModuleHandler;
@@ -56,7 +56,7 @@ class FieldInstanceStorageController extends ConfigStorageController {
    *   The entity type for which the instance is created.
    * @param array $entity_info
    *   An array of entity info for the entity type.
-   * @param \Drupal\Core\Config\ConfigFactory $config_factory
+   * @param \Drupal\Core\Config\ConfigFactoryInterface $config_factory
    *   The config factory service.
    * @param \Drupal\Core\Config\StorageInterface $config_storage
    *   The config storage service.
@@ -71,7 +71,7 @@ class FieldInstanceStorageController extends ConfigStorageController {
    * @param \Drupal\Core\KeyValueStore\StateInterface $state
    *   The state key value store.
    */
-  public function __construct($entity_type, array $entity_info, ConfigFactory $config_factory, StorageInterface $config_storage, QueryFactory $entity_query_factory, UuidInterface $uuid_service, EntityManagerInterface $entity_manager, ModuleHandler $module_handler, StateInterface $state) {
+  public function __construct($entity_type, array $entity_info, ConfigFactoryInterface $config_factory, StorageInterface $config_storage, QueryFactory $entity_query_factory, UuidInterface $uuid_service, EntityManagerInterface $entity_manager, ModuleHandler $module_handler, StateInterface $state) {
     parent::__construct($entity_type, $entity_info, $config_factory, $config_storage, $entity_query_factory, $uuid_service);
     $this->entityManager = $entity_manager;
     $this->moduleHandler = $module_handler;
diff --git a/core/modules/field/lib/Drupal/field/FieldStorageController.php b/core/modules/field/lib/Drupal/field/FieldStorageController.php
index 3f6408f..2788689 100644
--- a/core/modules/field/lib/Drupal/field/FieldStorageController.php
+++ b/core/modules/field/lib/Drupal/field/FieldStorageController.php
@@ -8,12 +8,11 @@
 namespace Drupal\field;
 
 use Drupal\Component\Uuid\UuidInterface;
-use Drupal\Core\Config\Config;
 use Drupal\Core\Config\Entity\ConfigStorageController;
 use Drupal\Core\Entity\EntityManagerInterface;
 use Drupal\Core\Entity\Query\QueryFactory;
 use Symfony\Component\DependencyInjection\ContainerInterface;
-use Drupal\Core\Config\ConfigFactory;
+use Drupal\Core\Config\ConfigFactoryInterface;
 use Drupal\Core\Config\StorageInterface;
 use Drupal\Core\Extension\ModuleHandler;
 use Drupal\Core\KeyValueStore\StateInterface;
@@ -51,7 +50,7 @@ class FieldStorageController extends ConfigStorageController {
    *   The entity type for which the instance is created.
    * @param array $entity_info
    *   An array of entity info for the entity type.
-   * @param \Drupal\Core\Config\ConfigFactory $config_factory
+   * @param \Drupal\Core\Config\ConfigFactoryInterface $config_factory
    *   The config factory service.
    * @param \Drupal\Core\Config\StorageInterface $config_storage
    *   The config storage service.
@@ -66,7 +65,7 @@ class FieldStorageController extends ConfigStorageController {
    * @param \Drupal\Core\KeyValueStore\StateInterface $state
    *   The state key value store.
    */
-  public function __construct($entity_type, array $entity_info, ConfigFactory $config_factory, StorageInterface $config_storage, QueryFactory $entity_query_factory, UuidInterface $uuid_service, EntityManagerInterface $entity_manager, ModuleHandler $module_handler, StateInterface $state) {
+  public function __construct($entity_type, array $entity_info, ConfigFactoryInterface $config_factory, StorageInterface $config_storage, QueryFactory $entity_query_factory, UuidInterface $uuid_service, EntityManagerInterface $entity_manager, ModuleHandler $module_handler, StateInterface $state) {
     parent::__construct($entity_type, $entity_info, $config_factory, $config_storage, $entity_query_factory, $uuid_service);
     $this->entityManager = $entity_manager;
     $this->moduleHandler = $module_handler;
diff --git a/core/modules/filter/lib/Drupal/filter/FilterFormatFormControllerBase.php b/core/modules/filter/lib/Drupal/filter/FilterFormatFormControllerBase.php
index 5ca05c2..98ff3fb 100644
--- a/core/modules/filter/lib/Drupal/filter/FilterFormatFormControllerBase.php
+++ b/core/modules/filter/lib/Drupal/filter/FilterFormatFormControllerBase.php
@@ -7,7 +7,7 @@
 
 namespace Drupal\filter;
 
-use Drupal\Core\Config\ConfigFactory;
+use Drupal\Core\Config\ConfigFactoryInterface;
 use Drupal\Core\Entity\EntityFormController;
 use Drupal\Core\Entity\Query\QueryFactory;
 use Drupal\filter\Plugin\Filter\FilterNull;
@@ -21,7 +21,7 @@
   /**
    * The config factory.
    *
-   * @var \Drupal\Core\Config\ConfigFactory
+   * @var \Drupal\Core\Config\ConfigFactoryInterface
    */
   protected $configFactory;
 
@@ -35,12 +35,12 @@
   /**
    * Constructs a new FilterFormatFormControllerBase.
    *
-   * @param \Drupal\Core\Config\ConfigFactory $config_factory
+   * @param \Drupal\Core\Config\ConfigFactoryInterface $config_factory
    *   The config factory.
    * @param \Drupal\Core\Entity\Query\QueryFactory $query_factory
    *   The entity query factory.
    */
-  public function __construct(ConfigFactory $config_factory, QueryFactory $query_factory) {
+  public function __construct(ConfigFactoryInterface $config_factory, QueryFactory $query_factory) {
     $this->configFactory = $config_factory;
     $this->queryFactory = $query_factory;
   }
diff --git a/core/modules/filter/lib/Drupal/filter/FilterFormatListController.php b/core/modules/filter/lib/Drupal/filter/FilterFormatListController.php
index cd94f86..1289fe9 100644
--- a/core/modules/filter/lib/Drupal/filter/FilterFormatListController.php
+++ b/core/modules/filter/lib/Drupal/filter/FilterFormatListController.php
@@ -8,7 +8,7 @@
 namespace Drupal\filter;
 
 use Drupal\Component\Utility\String;
-use Drupal\Core\Config\ConfigFactory;
+use Drupal\Core\Config\ConfigFactoryInterface;
 use Drupal\Core\Config\Entity\DraggableListController;
 use Drupal\Core\Entity\EntityControllerInterface;
 use Drupal\Core\Entity\EntityInterface;
@@ -29,7 +29,7 @@ class FilterFormatListController extends DraggableListController implements Enti
   /**
    * The config factory service.
    *
-   * @var \Drupal\Core\Config\ConfigFactory
+   * @var \Drupal\Core\Config\ConfigFactoryInterface
    */
   protected $configFactory;
 
@@ -44,10 +44,10 @@ class FilterFormatListController extends DraggableListController implements Enti
    *   The entity storage controller class.
    * @param \Drupal\Core\Extension\ModuleHandlerInterface $module_handler
    *   The module handler to invoke hooks on.
-   * @param \Drupal\Core\Config\ConfigFactory $config_factory
+   * @param \Drupal\Core\Config\ConfigFactoryInterface $config_factory
    *   The config factory.
    */
-  public function __construct($entity_type, array $entity_info, EntityStorageControllerInterface $storage, ModuleHandlerInterface $module_handler, ConfigFactory $config_factory) {
+  public function __construct($entity_type, array $entity_info, EntityStorageControllerInterface $storage, ModuleHandlerInterface $module_handler, ConfigFactoryInterface $config_factory) {
     parent::__construct($entity_type, $entity_info, $storage, $module_handler);
 
     $this->configFactory = $config_factory;
diff --git a/core/modules/forum/lib/Drupal/forum/Controller/ForumController.php b/core/modules/forum/lib/Drupal/forum/Controller/ForumController.php
index 2372e71..237b97d 100644
--- a/core/modules/forum/lib/Drupal/forum/Controller/ForumController.php
+++ b/core/modules/forum/lib/Drupal/forum/Controller/ForumController.php
@@ -7,7 +7,7 @@
 
 namespace Drupal\forum\Controller;
 
-use Drupal\Core\Config\Config;
+use Drupal\Core\Config\ConfigFactoryInterface;
 use Drupal\Core\Controller\ControllerInterface;
 use Drupal\Core\DependencyInjection\ContainerInjectionInterface;
 use Drupal\Core\Entity\EntityManagerInterface;
@@ -40,7 +40,7 @@ class ForumController implements ContainerInjectionInterface {
   /**
    * Config object for forum.settings.
    *
-   * @var \Drupal\Core\Config\Config
+   * @var \Drupal\Core\Config\ConfigFactoryInterface
    */
   protected $config;
 
@@ -68,7 +68,7 @@ class ForumController implements ContainerInjectionInterface {
   /**
    * Constructs a ForumController object.
    *
-   * @param \Drupal\Core\Config\Config $config
+   * @param \Drupal\Core\Config\ConfigFactoryInterface $config
    *   Config object for forum.settings.
    * @param \Drupal\forum\ForumManagerInterface $forum_manager
    *   The forum manager service.
@@ -81,8 +81,8 @@ class ForumController implements ContainerInjectionInterface {
    * @param \Drupal\Core\StringTranslation\TranslationInterface $translation_manager
    *   The translation manager service.
    */
-  public function __construct(Config $config, ForumManagerInterface $forum_manager, VocabularyStorageControllerInterface $vocabulary_storage_controller, TermStorageControllerInterface $term_storage_controller, EntityManagerInterface $entity_manager, TranslationInterface $translation_manager) {
-    $this->config = $config;
+  public function __construct(ConfigFactoryInterface $config, ForumManagerInterface $forum_manager, VocabularyStorageControllerInterface $vocabulary_storage_controller, TermStorageControllerInterface $term_storage_controller, EntityManagerInterface $entity_manager, TranslationInterface $translation_manager) {
+    $this->config = $config->get('forum.settings');
     $this->forumManager = $forum_manager;
     $this->vocabularyStorageController = $vocabulary_storage_controller;
     $this->termStorageController = $term_storage_controller;
@@ -95,7 +95,7 @@ public function __construct(Config $config, ForumManagerInterface $forum_manager
    */
   public static function create(ContainerInterface $container) {
     return new static(
-      $container->get('config.factory')->get('forum.settings'),
+      $container->get('config.factory'),
       $container->get('forum_manager'),
       $container->get('entity.manager')->getStorageController('taxonomy_vocabulary'),
       $container->get('entity.manager')->getStorageController('taxonomy_term'),
diff --git a/core/modules/forum/lib/Drupal/forum/Form/Overview.php b/core/modules/forum/lib/Drupal/forum/Form/Overview.php
index 560d535..7947b3a 100644
--- a/core/modules/forum/lib/Drupal/forum/Form/Overview.php
+++ b/core/modules/forum/lib/Drupal/forum/Form/Overview.php
@@ -9,7 +9,6 @@
 
 use Drupal\Core\Entity\EntityManagerInterface;
 use Drupal\taxonomy\Form\OverviewTerms;
-use Drupal\Core\Config\ConfigFactory;
 use Drupal\Core\Extension\ModuleHandlerInterface;
 use Symfony\Component\DependencyInjection\ContainerInterface;
 use Symfony\Component\HttpKernel\Exception\NotFoundHttpException;
diff --git a/core/modules/forum/lib/Drupal/forum/ForumBreadcrumbBuilder.php b/core/modules/forum/lib/Drupal/forum/ForumBreadcrumbBuilder.php
index e49f093..d0bdea1 100644
--- a/core/modules/forum/lib/Drupal/forum/ForumBreadcrumbBuilder.php
+++ b/core/modules/forum/lib/Drupal/forum/ForumBreadcrumbBuilder.php
@@ -8,7 +8,7 @@
 namespace Drupal\forum;
 
 use Drupal\Core\Breadcrumb\BreadcrumbBuilderBase;
-use Drupal\Core\Config\ConfigFactory;
+use Drupal\Core\Config\ConfigFactoryInterface;
 use Drupal\Core\Entity\EntityManagerInterface;
 use Drupal\forum\ForumManagerInterface;
 use Symfony\Cmf\Component\Routing\RouteObjectInterface;
@@ -21,7 +21,7 @@ class ForumBreadcrumbBuilder extends BreadcrumbBuilderBase {
   /**
    * Configuration object for this builder.
    *
-   * @var \Drupal\Core\Config\Config
+   * @var \Drupal\Core\Config\ConfigFactoryInterface
    */
   protected $config;
 
@@ -44,14 +44,14 @@ class ForumBreadcrumbBuilder extends BreadcrumbBuilderBase {
    *
    * @param \Drupal\Core\Entity\EntityManagerInterface $entity_manager
    *   The entity manager.
-   * @param \Drupal\Core\Config\ConfigFactory $configFactory
+   * @param \Drupal\Core\Config\ConfigFactoryInterface $configFactory
    *   The configuration factory.
    * @param \Drupal\forum\ForumManagerInterface $forum_manager
    *   The forum manager service.
    */
-  public function __construct(EntityManagerInterface $entity_manager, ConfigFactory $configFactory, ForumManagerInterface $forum_manager) {
+  public function __construct(EntityManagerInterface $entity_manager, ConfigFactoryInterface $config_factory, ForumManagerInterface $forum_manager) {
     $this->entityManager = $entity_manager;
-    $this->config = $configFactory->get('forum.settings');
+    $this->config = $config_factory->get('forum.settings');
     $this->forumManager = $forum_manager;
   }
 
diff --git a/core/modules/forum/lib/Drupal/forum/ForumManager.php b/core/modules/forum/lib/Drupal/forum/ForumManager.php
index 5c530c7..bcc7372 100644
--- a/core/modules/forum/lib/Drupal/forum/ForumManager.php
+++ b/core/modules/forum/lib/Drupal/forum/ForumManager.php
@@ -7,7 +7,7 @@
 
 namespace Drupal\forum;
 
-use Drupal\Core\Config\ConfigFactory;
+use Drupal\Core\Config\ConfigFactoryInterface;
 use Drupal\Core\Database\Connection;
 use Drupal\Core\Entity\EntityManagerInterface;
 use Drupal\Core\StringTranslation\TranslationInterface;
@@ -43,7 +43,7 @@ class ForumManager implements ForumManagerInterface {
   /**
    * Forum settings config object.
    *
-   * @var \Drupal\Core\Config\ConfigFactory
+   * @var \Drupal\Core\Config\ConfigFactoryInterface
    */
   protected $configFactory;
 
@@ -113,7 +113,7 @@ class ForumManager implements ForumManagerInterface {
   /**
    * Constructs the forum manager service.
    *
-   * @param \Drupal\Core\Config\ConfigFactory $config_factory
+   * @param \Drupal\Core\Config\ConfigFactoryInterface $config_factory
    *   The config factory service.
    * @param \Drupal\Core\Entity\EntityManagerInterface $entity_manager
    *   The entity manager service.
@@ -124,7 +124,7 @@ class ForumManager implements ForumManagerInterface {
    * @param \Drupal\Core\StringTranslation\TranslationInterface $translation_manager
    *   The translation manager service.
    */
-  public function __construct(ConfigFactory $config_factory, EntityManagerInterface $entity_manager, Connection $connection, FieldInfo $field_info, TranslationInterface $translation_manager) {
+  public function __construct(ConfigFactoryInterface $config_factory, EntityManagerInterface $entity_manager, Connection $connection, FieldInfo $field_info, TranslationInterface $translation_manager) {
     $this->configFactory = $config_factory;
     $this->entityManager = $entity_manager;
     $this->connection = $connection;
diff --git a/core/modules/forum/tests/Drupal/forum/Tests/ForumManagerTest.php b/core/modules/forum/tests/Drupal/forum/Tests/ForumManagerTest.php
index 8d3be5f..89f1460 100644
--- a/core/modules/forum/tests/Drupal/forum/Tests/ForumManagerTest.php
+++ b/core/modules/forum/tests/Drupal/forum/Tests/ForumManagerTest.php
@@ -34,7 +34,7 @@ public function testGetIndex() {
       ->disableOriginalConstructor()
       ->getMock();
 
-    $config_factory = $this->getMockBuilder('\Drupal\Core\Config\ConfigFactory')
+    $config_factory = $this->getMockBuilder('\Drupal\Core\Config\ConfigFactoryInterface')
       ->disableOriginalConstructor()
       ->getMock();
 
diff --git a/core/modules/language/lib/Drupal/language/Form/ContentLanguageSettingsForm.php b/core/modules/language/lib/Drupal/language/Form/ContentLanguageSettingsForm.php
index a253854..bd445dc 100644
--- a/core/modules/language/lib/Drupal/language/Form/ContentLanguageSettingsForm.php
+++ b/core/modules/language/lib/Drupal/language/Form/ContentLanguageSettingsForm.php
@@ -7,7 +7,7 @@
 
 namespace Drupal\language\Form;
 
-use Drupal\Core\Config\ConfigFactory;
+use Drupal\Core\Config\ConfigFactoryInterface;
 use Drupal\Core\Config\Context\ContextInterface;
 use Drupal\Core\Entity\EntityManagerInterface;
 use Drupal\Core\Form\ConfigFormBase;
@@ -28,14 +28,14 @@ class ContentLanguageSettingsForm extends ConfigFormBase {
   /**
    * Constructs a ContentLanguageSettingsForm object.
    *
-   * @param \Drupal\Core\Config\ConfigFactory $config_factory
+   * @param \Drupal\Core\Config\ConfigFactoryInterface $config_factory
    *   The config factory.
    * @param \Drupal\Core\Config\Context\ContextInterface $context
    *   The configuration context to use.
    * @param \Drupal\Core\Entity\EntityManagerInterface $entity_manager
    *   The entity manager.
    */
-  public function __construct(ConfigFactory $config_factory, ContextInterface $context, EntityManagerInterface $entity_manager) {
+  public function __construct(ConfigFactoryInterface $config_factory, ContextInterface $context, EntityManagerInterface $entity_manager) {
     parent::__construct($config_factory, $context);
 
     $this->entityManager = $entity_manager;
diff --git a/core/modules/language/lib/Drupal/language/Form/NegotiationBrowserForm.php b/core/modules/language/lib/Drupal/language/Form/NegotiationBrowserForm.php
index 2271b14..a5c84ff 100644
--- a/core/modules/language/lib/Drupal/language/Form/NegotiationBrowserForm.php
+++ b/core/modules/language/lib/Drupal/language/Form/NegotiationBrowserForm.php
@@ -7,7 +7,7 @@
 
 namespace Drupal\language\Form;
 
-use Drupal\Core\Config\ConfigFactory;
+use Drupal\Core\Config\ConfigFactoryInterface;
 use Drupal\Core\Config\Context\ContextInterface;
 use Drupal\Core\Extension\ModuleHandlerInterface;
 use Drupal\Core\Form\ConfigFormBase;
@@ -31,7 +31,7 @@ class NegotiationBrowserForm extends ConfigFormBase {
    * @param \Drupal\Core\Extension\ModuleHandlerInterface $module_handler
    *   The module handler
    */
-  public function __construct(ConfigFactory $config_factory, ContextInterface $context, ModuleHandlerInterface $module_handler) {
+  public function __construct(ConfigFactoryInterface $config_factory, ContextInterface $context, ModuleHandlerInterface $module_handler) {
     parent::__construct($config_factory, $context);
     $this->moduleHandler = $module_handler;
   }
diff --git a/core/modules/language/lib/Drupal/language/HttpKernel/PathProcessorLanguage.php b/core/modules/language/lib/Drupal/language/HttpKernel/PathProcessorLanguage.php
index d212c7b..796c686 100644
--- a/core/modules/language/lib/Drupal/language/HttpKernel/PathProcessorLanguage.php
+++ b/core/modules/language/lib/Drupal/language/HttpKernel/PathProcessorLanguage.php
@@ -8,7 +8,7 @@
 namespace Drupal\language\HttpKernel;
 
 use Drupal\Component\Utility\Settings;
-use Drupal\Core\Config\ConfigFactory;
+use Drupal\Core\Config\ConfigFactoryInterface;
 use Drupal\Core\Language\Language;
 use Drupal\Core\Language\LanguageManager;
 use Drupal\Core\PathProcessor\InboundPathProcessorInterface;
@@ -24,7 +24,7 @@ class PathProcessorLanguage implements InboundPathProcessorInterface, OutboundPa
   /**
    * A config factory for retrieving required config settings.
    *
-   * @var \Drupal\Core\Config\ConfigFactory
+   * @var \Drupal\Core\Config\ConfigFactoryInterface
    */
   protected $config;
 
@@ -53,14 +53,14 @@ class PathProcessorLanguage implements InboundPathProcessorInterface, OutboundPa
   /**
    * Constructs a PathProcessorLanguage object.
    *
-   * @param \Drupal\Core\Config\ConfigFactory $config
+   * @param \Drupal\Core\Config\ConfigFactoryInterface $config
    *   A config factory object for retrieving configuration settings.
    *
    * @param array $languages
    *   An array of languages, keyed by language code, representing the languages
    *   currently enabled on the site.
    */
-  public function __construct(ConfigFactory $config, Settings $settings, LanguageManager $language_manager, array $languages = array()) {
+  public function __construct(ConfigFactoryInterface $config, Settings $settings, LanguageManager $language_manager, array $languages = array()) {
     $this->config = $config;
     $this->mixedModeSessions = $settings->get('mixed_mode_sessions', FALSE);
     $this->languageManager = $language_manager;
diff --git a/core/modules/locale/lib/Drupal/locale/LocaleTranslation.php b/core/modules/locale/lib/Drupal/locale/LocaleTranslation.php
index b0983de..2c4590f 100644
--- a/core/modules/locale/lib/Drupal/locale/LocaleTranslation.php
+++ b/core/modules/locale/lib/Drupal/locale/LocaleTranslation.php
@@ -8,7 +8,7 @@
 namespace Drupal\locale;
 
 use Drupal\Core\Cache\CacheBackendInterface;
-use Drupal\Core\Config\ConfigFactory;
+use Drupal\Core\Config\ConfigFactoryInterface;
 use Drupal\Core\DestructableInterface;
 use Drupal\Core\Language\Language;
 use Drupal\Core\Lock\LockBackendAbstract;
@@ -35,7 +35,7 @@ class LocaleTranslation implements TranslatorInterface, DestructableInterface {
   /**
    * The configuration factory.
    *
-   * @var \Drupal\Core\Config\ConfigFactory
+   * @var \Drupal\Core\Config\ConfigFactoryInterface
    */
   protected $configFactory;
 
@@ -71,10 +71,10 @@ class LocaleTranslation implements TranslatorInterface, DestructableInterface {
    *   The cache backend.
    * @param \Drupal\Core\Lock\LockBackendInterface $lock
    *   The lock backend.
-   * @param \Drupal\Core\Config\ConfigFactory $config_factory
+   * @param \Drupal\Core\Config\ConfigFactoryInterface $config_factory
    *   The config factory.
    */
-  public function __construct(StringStorageInterface $storage, CacheBackendInterface $cache, LockBackendInterface $lock, ConfigFactory $config_factory) {
+  public function __construct(StringStorageInterface $storage, CacheBackendInterface $cache, LockBackendInterface $lock, ConfigFactoryInterface $config_factory) {
     $this->storage = $storage;
     $this->cache = $cache;
     $this->lock = $lock;
diff --git a/core/modules/rest/lib/Drupal/rest/EventSubscriber/RouteSubscriber.php b/core/modules/rest/lib/Drupal/rest/EventSubscriber/RouteSubscriber.php
index e7d9ea3..d65274a 100644
--- a/core/modules/rest/lib/Drupal/rest/EventSubscriber/RouteSubscriber.php
+++ b/core/modules/rest/lib/Drupal/rest/EventSubscriber/RouteSubscriber.php
@@ -7,8 +7,8 @@
 
 namespace Drupal\rest\EventSubscriber;
 
-use Drupal\Core\Config\ConfigFactory;
 use Drupal\Core\Routing\RouteSubscriberBase;
+use Drupal\Core\Config\ConfigFactoryInterface;
 use Drupal\rest\Plugin\Type\ResourcePluginManager;
 use Symfony\Component\Routing\RouteCollection;
 
@@ -27,7 +27,7 @@ class RouteSubscriber extends RouteSubscriberBase {
   /**
    * The Drupal configuration factory.
    *
-   * @var \Drupal\Core\Config\ConfigFactory
+   * @var \Drupal\Core\Config\ConfigFactoryInterface
    */
   protected $config;
 
@@ -36,10 +36,10 @@ class RouteSubscriber extends RouteSubscriberBase {
    *
    * @param \Drupal\rest\Plugin\Type\ResourcePluginManager $manager
    *   The resource plugin manager.
-   * @param \Drupal\Core\Config\ConfigFactory $config
+   * @param \Drupal\Core\Config\ConfigFactoryInterface $config
    *   The configuration factory holding resource settings.
    */
-  public function __construct(ResourcePluginManager $manager, ConfigFactory $config) {
+  public function __construct(ResourcePluginManager $manager, ConfigFactoryInterface $config) {
     $this->manager = $manager;
     $this->config = $config;
   }
diff --git a/core/modules/search/lib/Drupal/search/Form/SearchSettingsForm.php b/core/modules/search/lib/Drupal/search/Form/SearchSettingsForm.php
index 0d3e115..8351644 100644
--- a/core/modules/search/lib/Drupal/search/Form/SearchSettingsForm.php
+++ b/core/modules/search/lib/Drupal/search/Form/SearchSettingsForm.php
@@ -7,7 +7,7 @@
 namespace Drupal\search\Form;
 
 use Drupal\Core\Cache\Cache;
-use Drupal\Core\Config\ConfigFactory;
+use Drupal\Core\Config\ConfigFactoryInterface;
 use Drupal\Core\Config\Context\ContextInterface;
 use Drupal\Core\Extension\ModuleHandlerInterface;
 use Drupal\Core\KeyValueStore\StateInterface;
@@ -52,7 +52,7 @@ class SearchSettingsForm extends ConfigFormBase {
   /**
    * Constructs a \Drupal\search\Form\SearchSettingsForm object.
    *
-   * @param \Drupal\Core\Config\ConfigFactory $config_factory
+   * @param \Drupal\Core\Config\ConfigFactoryInterface $config_factory
    *   The configuration factory object that manages search settings.
    * @param \Drupal\Core\Config\Context\ContextInterface $context
    *   The context interface
@@ -63,7 +63,7 @@ class SearchSettingsForm extends ConfigFormBase {
    * @param \Drupal\Core\KeyValueStore\StateInterface $state
    *   The state key/value store interface, gives access to state based config settings.
    */
-  public function __construct(ConfigFactory $config_factory, ContextInterface $context, SearchPluginManager $manager, ModuleHandlerInterface $module_handler, StateInterface $state) {
+  public function __construct(ConfigFactoryInterface $config_factory, ContextInterface $context, SearchPluginManager $manager, ModuleHandlerInterface $module_handler, StateInterface $state) {
     parent::__construct($config_factory, $context);
     $this->searchSettings = $config_factory->get('search.settings');
     $this->searchPluginManager = $manager;
diff --git a/core/modules/search/lib/Drupal/search/SearchPluginManager.php b/core/modules/search/lib/Drupal/search/SearchPluginManager.php
index dac919b..093fd8e 100644
--- a/core/modules/search/lib/Drupal/search/SearchPluginManager.php
+++ b/core/modules/search/lib/Drupal/search/SearchPluginManager.php
@@ -8,7 +8,7 @@
 namespace Drupal\search;
 
 use Drupal\Component\Utility\NestedArray;
-use Drupal\Core\Config\ConfigFactory;
+use Drupal\Core\Config\ConfigFactoryInterface;
 use Drupal\Core\Plugin\DefaultPluginManager;
 use Drupal\Core\Session\AccountInterface;
 use Drupal\Core\Cache\CacheBackendInterface;
@@ -22,14 +22,14 @@ class SearchPluginManager extends DefaultPluginManager {
   /**
    * The config factory.
    *
-   * @var \Drupal\Core\Config\ConfigFactory
+   * @var \Drupal\Core\Config\ConfigFactoryInterface
    */
   protected $configFactory;
 
   /**
    * {@inheritdoc}
    */
-  public function __construct(\Traversable $namespaces, ConfigFactory $config_factory, CacheBackendInterface $cache_backend, LanguageManager $language_manager) {
+  public function __construct(\Traversable $namespaces, ConfigFactoryInterface $config_factory, CacheBackendInterface $cache_backend, LanguageManager $language_manager) {
     parent::__construct('Plugin/Search', $namespaces, 'Drupal\search\Annotation\SearchPlugin');
 
     $this->configFactory = $config_factory;
diff --git a/core/modules/statistics/lib/Drupal/statistics/StatisticsSettingsForm.php b/core/modules/statistics/lib/Drupal/statistics/StatisticsSettingsForm.php
index e8646cd..3cfb80d 100644
--- a/core/modules/statistics/lib/Drupal/statistics/StatisticsSettingsForm.php
+++ b/core/modules/statistics/lib/Drupal/statistics/StatisticsSettingsForm.php
@@ -9,7 +9,7 @@
 use Drupal\Core\Config\Context\ContextInterface;
 use Drupal\Core\Extension\ModuleHandlerInterface;
 use Drupal\Core\Form\ConfigFormBase;
-use Drupal\Core\Config\ConfigFactory;
+use Drupal\Core\Config\ConfigFactoryInterface;
 use Symfony\Component\DependencyInjection\ContainerInterface;
 
 /**
@@ -27,14 +27,14 @@ class StatisticsSettingsForm extends ConfigFormBase {
   /**
    * Constructs a \Drupal\user\StatisticsSettingsForm object.
    *
-   * @param \Drupal\Core\Config\ConfigFactory $config_factory
+   * @param \Drupal\Core\Config\ConfigFactoryInterface $config_factory
    *   The factory for configuration objects.
    * @param \Drupal\Core\Config\Context\ContextInterface $context
    *   The configuration context to use.
    * @param \Drupal\Core\Extension\ModuleHandlerInterface $module_handler
    *   The module handler.
    */
-  public function __construct(ConfigFactory $config_factory, ContextInterface $context, ModuleHandlerInterface $module_handler) {
+  public function __construct(ConfigFactoryInterface $config_factory, ContextInterface $context, ModuleHandlerInterface $module_handler) {
     parent::__construct($config_factory, $context);
 
     $this->moduleHandler = $module_handler;
diff --git a/core/modules/system/lib/Drupal/system/Form/CronForm.php b/core/modules/system/lib/Drupal/system/Form/CronForm.php
index 5d94762..a882f63 100644
--- a/core/modules/system/lib/Drupal/system/Form/CronForm.php
+++ b/core/modules/system/lib/Drupal/system/Form/CronForm.php
@@ -7,7 +7,7 @@
 
 namespace Drupal\system\Form;
 
-use Drupal\Core\Config\ConfigFactory;
+use Drupal\Core\Config\ConfigFactoryInterface;
 use Drupal\Core\Config\Context\ContextInterface;
 use Drupal\Core\KeyValueStore\StateInterface;
 use Drupal\Core\Form\ConfigFormBase;
@@ -29,14 +29,14 @@ class CronForm extends ConfigFormBase {
   /**
    * Constructs a CronForm object.
    *
-   * @param \Drupal\Core\Config\ConfigFactory $config_factory
+   * @param \Drupal\Core\Config\ConfigFactoryInterface $config_factory
    *   The factory for configuration objects.
    * @param \Drupal\Core\Config\Context\ContextInterface $context
    *   The configuration context used for this configuration object.
    * @param \Drupal\Core\KeyValueStore\StateInterface $state
    *   The state key value store.
    */
-  public function __construct(ConfigFactory $config_factory, ContextInterface $context, StateInterface $state) {
+  public function __construct(ConfigFactoryInterface $config_factory, ContextInterface $context, StateInterface $state) {
     parent::__construct($config_factory, $context);
     $this->state = $state;
   }
diff --git a/core/modules/system/lib/Drupal/system/Form/ImageToolkitForm.php b/core/modules/system/lib/Drupal/system/Form/ImageToolkitForm.php
index 6e3ebeb..af576b1 100644
--- a/core/modules/system/lib/Drupal/system/Form/ImageToolkitForm.php
+++ b/core/modules/system/lib/Drupal/system/Form/ImageToolkitForm.php
@@ -7,7 +7,7 @@
 
 namespace Drupal\system\Form;
 
-use Drupal\Core\Config\ConfigFactory;
+use Drupal\Core\Config\ConfigFactoryInterface;
 use Drupal\Core\Config\Context\ContextInterface;
 use Drupal\Core\Form\ConfigFormBase;
 use Drupal\Core\ImageToolkit\ImageToolkitManager;
@@ -28,14 +28,14 @@ class ImageToolkitForm extends ConfigFormBase {
   /**
    * Constructs a ImageToolkitForm object.
    *
-   * @param \Drupal\Core\Config\ConfigFactory $config_factory
+   * @param \Drupal\Core\Config\ConfigFactoryInterface $config_factory
    *   The factory for configuration objects.
    * @param \Drupal\Core\Config\Context\ContextInterface $context
    *   The configuration context used for this configuration object.
    * @param \Drupal\Core\ImageToolkit\ImageToolkitManager $manager
    *   The image toolkit plugin manager.
    */
-  public function __construct(ConfigFactory $config_factory, ContextInterface $context, ImageToolkitManager $manager) {
+  public function __construct(ConfigFactoryInterface $config_factory, ContextInterface $context, ImageToolkitManager $manager) {
     parent::__construct($config_factory, $context);
 
     foreach ($manager->getAvailableToolkits() as $id => $definition) {
diff --git a/core/modules/system/lib/Drupal/system/Form/PerformanceForm.php b/core/modules/system/lib/Drupal/system/Form/PerformanceForm.php
index f596078..c2d53b9 100644
--- a/core/modules/system/lib/Drupal/system/Form/PerformanceForm.php
+++ b/core/modules/system/lib/Drupal/system/Form/PerformanceForm.php
@@ -8,7 +8,7 @@
 namespace Drupal\system\Form;
 
 use Drupal\Core\Form\ConfigFormBase;
-use Drupal\Core\Config\ConfigFactory;
+use Drupal\Core\Config\ConfigFactoryInterface;
 use Drupal\Core\Config\Context\ContextInterface;
 use Drupal\Core\Cache\CacheBackendInterface;
 use Symfony\Component\DependencyInjection\ContainerInterface;
@@ -28,13 +28,13 @@ class PerformanceForm extends ConfigFormBase {
   /**
    * Constructs a PerformanceForm object.
    *
-   * @param \Drupal\Core\Config\ConfigFactory $config_factory
+   * @param \Drupal\Core\Config\ConfigFactoryInterface $config_factory
    *   The factory for configuration objects.
    * @param \Drupal\Core\Config\Context\ContextInterface $context
    *   The configuration context used for this configuration object.
    * @param \Drupal\Core\Cache\CacheBackendInterface $page_cache
    */
-  public function __construct(ConfigFactory $config_factory, ContextInterface $context, CacheBackendInterface $page_cache) {
+  public function __construct(ConfigFactoryInterface $config_factory, ContextInterface $context, CacheBackendInterface $page_cache) {
     parent::__construct($config_factory, $context);
 
     $this->pageCache = $page_cache;
diff --git a/core/modules/system/lib/Drupal/system/Form/RegionalForm.php b/core/modules/system/lib/Drupal/system/Form/RegionalForm.php
index a75ff7f..352f80e 100644
--- a/core/modules/system/lib/Drupal/system/Form/RegionalForm.php
+++ b/core/modules/system/lib/Drupal/system/Form/RegionalForm.php
@@ -7,7 +7,7 @@
 
 namespace Drupal\system\Form;
 
-use Drupal\Core\Config\ConfigFactory;
+use Drupal\Core\Config\ConfigFactoryInterface;
 use Drupal\Core\Config\Context\ContextInterface;
 use Drupal\Core\Locale\CountryManagerInterface;
 use Drupal\Core\Form\ConfigFormBase;
@@ -28,14 +28,14 @@ class RegionalForm extends ConfigFormBase {
   /**
    * Constructs a RegionalForm object.
    *
-   * @param \Drupal\Core\Config\ConfigFactory $config_factory
+   * @param \Drupal\Core\Config\ConfigFactoryInterface $config_factory
    *   The factory for configuration objects.
    * @param \Drupal\Core\Config\Context\ContextInterface $context
    *   The configuration context used for this configuration object.
    * @param \Drupal\Core\Locale\CountryManagerInterface $country_manager
    *   The country manager.
    */
-  public function __construct(ConfigFactory $config_factory, ContextInterface $context, CountryManagerInterface $country_manager) {
+  public function __construct(ConfigFactoryInterface $config_factory, ContextInterface $context, CountryManagerInterface $country_manager) {
     parent::__construct($config_factory, $context);
     $this->countryManager = $country_manager;
   }
diff --git a/core/modules/system/lib/Drupal/system/Form/SiteInformationForm.php b/core/modules/system/lib/Drupal/system/Form/SiteInformationForm.php
index 34e3584..b7960ec 100644
--- a/core/modules/system/lib/Drupal/system/Form/SiteInformationForm.php
+++ b/core/modules/system/lib/Drupal/system/Form/SiteInformationForm.php
@@ -7,7 +7,7 @@
 
 namespace Drupal\system\Form;
 
-use Drupal\Core\Config\ConfigFactory;
+use Drupal\Core\Config\ConfigFactoryInterface;
 use Drupal\Core\Config\Context\ContextInterface;
 use Drupal\Core\Path\AliasManagerInterface;
 use Drupal\Core\Form\ConfigFormBase;
@@ -28,14 +28,14 @@ class SiteInformationForm extends ConfigFormBase {
   /**
    * Constructs a SiteInformationForm object.
    *
-   * @param \Drupal\Core\Config\ConfigFactory $config_factory
+   * @param \Drupal\Core\Config\ConfigFactoryInterface $config_factory
    *   The factory for configuration objects.
    * @param \Drupal\Core\Config\Context\ContextInterface $context
    *   The configuration context used for this configuration object.
    * @param \Drupal\Core\Path\AliasManagerInterface $alias_manager
    *   The path alias manager.
    */
-  public function __construct(ConfigFactory $config_factory, ContextInterface $context, AliasManagerInterface $alias_manager) {
+  public function __construct(ConfigFactoryInterface $config_factory, ContextInterface $context, AliasManagerInterface $alias_manager) {
     parent::__construct($config_factory, $context);
 
     $this->aliasManager = $alias_manager;
diff --git a/core/modules/system/lib/Drupal/system/Form/SiteMaintenanceModeForm.php b/core/modules/system/lib/Drupal/system/Form/SiteMaintenanceModeForm.php
index 693dc28..73170c6 100644
--- a/core/modules/system/lib/Drupal/system/Form/SiteMaintenanceModeForm.php
+++ b/core/modules/system/lib/Drupal/system/Form/SiteMaintenanceModeForm.php
@@ -7,7 +7,7 @@
 
 namespace Drupal\system\Form;
 
-use Drupal\Core\Config\ConfigFactory;
+use Drupal\Core\Config\ConfigFactoryInterface;
 use Drupal\Core\Config\Context\ContextInterface;
 use Drupal\Core\KeyValueStore\StateInterface;
 use Drupal\Core\Form\ConfigFormBase;
@@ -28,14 +28,14 @@ class SiteMaintenanceModeForm extends ConfigFormBase {
   /**
    * Constructs a new SiteMaintenanceModeForm.
    *
-   * @param \Drupal\Core\Config\ConfigFactory $config_factory
+   * @param \Drupal\Core\Config\ConfigFactoryInterface $config_factory
    *   The factory for configuration objects.
    * @param \Drupal\Core\Config\Context\ContextInterface $context
    *   The configuration context to use.
    * @param \Drupal\Core\KeyValueStore\StateInterface $state
    *   The state keyvalue collection to use.
    */
-  public function __construct(ConfigFactory $config_factory, ContextInterface $context, StateInterface $state) {
+  public function __construct(ConfigFactoryInterface $config_factory, ContextInterface $context, StateInterface $state) {
     parent::__construct($config_factory, $context);
     $this->state = $state;
   }
diff --git a/core/modules/system/lib/Drupal/system/Form/ThemeSettingsForm.php b/core/modules/system/lib/Drupal/system/Form/ThemeSettingsForm.php
index ec76227..e6b5b5b 100644
--- a/core/modules/system/lib/Drupal/system/Form/ThemeSettingsForm.php
+++ b/core/modules/system/lib/Drupal/system/Form/ThemeSettingsForm.php
@@ -11,7 +11,7 @@
 use Symfony\Component\DependencyInjection\ContainerInterface;
 use Symfony\Component\HttpKernel\Exception\NotFoundHttpException;
 use Drupal\Core\Cache\Cache;
-use Drupal\Core\Config\ConfigFactory;
+use Drupal\Core\Config\ConfigFactoryInterface;
 use Drupal\Core\Config\Context\ContextInterface;
 use Drupal\Core\Extension\ModuleHandlerInterface;
 use Drupal\Core\Form\ConfigFormBase;
@@ -31,14 +31,14 @@ class ThemeSettingsForm extends ConfigFormBase {
   /**
    * Constructs a ThemeSettingsForm object.
    *
-   * @param \Drupal\Core\Config\ConfigFactory $config_factory
+   * @param \Drupal\Core\Config\ConfigFactoryInterface $config_factory
    *   The factory for configuration objects.
    * @param \Drupal\Core\Config\Context\ContextInterface $context
    *   The configuration context to use.
-   * @param \Drupal\Core\Extension\ModuleHandlerInterface
+   * @param \Drupal\Core\Extension\ModuleHandlerInterface $module_handler
    *   The module handler instance to use.
    */
-  public function __construct(ConfigFactory $config_factory, ContextInterface $context, ModuleHandlerInterface $module_handler) {
+  public function __construct(ConfigFactoryInterface $config_factory, ContextInterface $context, ModuleHandlerInterface $module_handler) {
     parent::__construct($config_factory, $context);
 
     $this->moduleHandler = $module_handler;
diff --git a/core/modules/system/lib/Drupal/system/PathBasedBreadcrumbBuilder.php b/core/modules/system/lib/Drupal/system/PathBasedBreadcrumbBuilder.php
index 1f59256..050b341 100644
--- a/core/modules/system/lib/Drupal/system/PathBasedBreadcrumbBuilder.php
+++ b/core/modules/system/lib/Drupal/system/PathBasedBreadcrumbBuilder.php
@@ -8,7 +8,7 @@
 namespace Drupal\system;
 
 use Drupal\Core\Breadcrumb\BreadcrumbBuilderBase;
-use Drupal\Core\Config\ConfigFactory;
+use Drupal\Core\Config\ConfigFactoryInterface;
 use Drupal\Core\Controller\TitleResolverInterface;
 use Drupal\Core\Access\AccessManager;
 use Drupal\Core\Entity\EntityManagerInterface;
@@ -87,12 +87,12 @@ class PathBasedBreadcrumbBuilder extends BreadcrumbBuilderBase {
    *   The dynamic router service.
    * @param \Drupal\Core\PathProcessor\InboundPathProcessorInterface $path_processor
    *   The inbound path processor.
-   * @param \Drupal\Core\Config\ConfigFactory $config_factory
+   * @param \Drupal\Core\Config\ConfigFactoryInterface $config_factory
    *   The config factory service.
    * @param \Drupal\Core\Controller\TitleResolverInterface $title_resolver
    *   The title resolver service.
    */
-  public function __construct(Request $request, EntityManagerInterface $entity_manager, AccessManager $access_manager, RequestMatcherInterface $router, InboundPathProcessorInterface $path_processor, ConfigFactory $config_factory, TitleResolverInterface $title_resolver) {
+  public function __construct(Request $request, EntityManagerInterface $entity_manager, AccessManager $access_manager, RequestMatcherInterface $router, InboundPathProcessorInterface $path_processor, ConfigFactoryInterface $config_factory, TitleResolverInterface $title_resolver) {
     $this->request = $request;
     $this->accessManager = $access_manager;
     $this->menuStorage = $entity_manager->getStorageController('menu');
diff --git a/core/modules/taxonomy/lib/Drupal/taxonomy/TermFormController.php b/core/modules/taxonomy/lib/Drupal/taxonomy/TermFormController.php
index 925d83c..dfc4118 100644
--- a/core/modules/taxonomy/lib/Drupal/taxonomy/TermFormController.php
+++ b/core/modules/taxonomy/lib/Drupal/taxonomy/TermFormController.php
@@ -8,7 +8,7 @@
 namespace Drupal\taxonomy;
 
 use Drupal\Core\Cache\Cache;
-use Drupal\Core\Config\ConfigFactory;
+use Drupal\Core\Config\ConfigFactoryInterface;
 use Drupal\Core\Entity\ContentEntityFormController;
 use Drupal\Core\Entity\EntityManagerInterface;
 use Drupal\Core\Language\Language;
@@ -22,7 +22,7 @@ class TermFormController extends ContentEntityFormController {
   /**
    * The config factory.
    *
-   * @var \Drupal\Core\Config\ConfigFactory
+   * @var \Drupal\Core\Config\ConfigFactoryInterface
    */
   protected $configFactory;
 
@@ -31,10 +31,10 @@ class TermFormController extends ContentEntityFormController {
    *
    * @param \Drupal\Core\Entity\EntityManagerInterface $entity_manager
    *   The entity manager.
-   * @param \Drupal\Core\Config\ConfigFactory $config_factory
+   * @param \Drupal\Core\Config\ConfigFactoryInterface $config_factory
    *   The config factory.
    */
-  public function __construct(EntityManagerInterface $entity_manager, ConfigFactory $config_factory) {
+  public function __construct(EntityManagerInterface $entity_manager, ConfigFactoryInterface $config_factory) {
     parent::__construct($entity_manager);
     $this->configFactory = $config_factory;
   }
diff --git a/core/modules/update/lib/Drupal/update/UpdateFetcher.php b/core/modules/update/lib/Drupal/update/UpdateFetcher.php
index 6893210..c8a5e90 100644
--- a/core/modules/update/lib/Drupal/update/UpdateFetcher.php
+++ b/core/modules/update/lib/Drupal/update/UpdateFetcher.php
@@ -7,7 +7,7 @@
 
 namespace Drupal\update;
 
-use Drupal\Core\Config\ConfigFactory;
+use Drupal\Core\Config\ConfigFactoryInterface;
 use Guzzle\Http\ClientInterface;
 use Guzzle\Http\Exception\RequestException;
 
@@ -38,12 +38,12 @@ class UpdateFetcher {
   /**
    * Constructs a UpdateFetcher.
    *
-   * @param \Drupal\Core\Config\ConfigFactory $config_factory
+   * @param \Drupal\Core\Config\ConfigFactoryInterface $config_factory
    *   The config factory.
    * @param \Guzzle\Http\ClientInterface $http_client
    *   A Guzzle client object.
    */
-  public function __construct(ConfigFactory $config_factory, ClientInterface $http_client) {
+  public function __construct(ConfigFactoryInterface $config_factory, ClientInterface $http_client) {
     $this->fetchUrl = $config_factory->get('update.settings')->get('fetch.url');
     $this->httpClient = $http_client;
   }
diff --git a/core/modules/user/lib/Drupal/user/AccountSettingsForm.php b/core/modules/user/lib/Drupal/user/AccountSettingsForm.php
index ace1834..0a9ce82 100644
--- a/core/modules/user/lib/Drupal/user/AccountSettingsForm.php
+++ b/core/modules/user/lib/Drupal/user/AccountSettingsForm.php
@@ -8,7 +8,7 @@
 namespace Drupal\user;
 
 use Drupal\Core\Form\ConfigFormBase;
-use Drupal\Core\Config\ConfigFactory;
+use Drupal\Core\Config\ConfigFactoryInterface;
 use Drupal\Core\Config\Context\ContextInterface;
 use Drupal\Core\Extension\ModuleHandler;
 use Symfony\Component\DependencyInjection\ContainerInterface;
@@ -28,14 +28,14 @@ class AccountSettingsForm extends ConfigFormBase {
   /**
    * Constructs a \Drupal\user\AccountSettingsForm object.
    *
-   * @param \Drupal\Core\Config\ConfigFactory $config_factory
+   * @param \Drupal\Core\Config\ConfigFactoryInterface $config_factory
    *   The factory for configuration objects.
    * @param \Drupal\Core\Config\Context\ContextInterface $context
    *   The configuration context.
    * @param \Drupal\Core\Extension\ModuleHandler $module_handler
    *   The module handler.
    */
-  public function __construct(ConfigFactory $config_factory, ContextInterface $context, ModuleHandler $module_handler) {
+  public function __construct(ConfigFactoryInterface $config_factory, ContextInterface $context, ModuleHandler $module_handler) {
     parent::__construct($config_factory, $context);
     $this->moduleHandler = $module_handler;
   }
diff --git a/core/modules/user/lib/Drupal/user/Form/UserCancelForm.php b/core/modules/user/lib/Drupal/user/Form/UserCancelForm.php
index e1a3c6a..b9a0451 100644
--- a/core/modules/user/lib/Drupal/user/Form/UserCancelForm.php
+++ b/core/modules/user/lib/Drupal/user/Form/UserCancelForm.php
@@ -7,7 +7,7 @@
 
 namespace Drupal\user\Form;
 
-use Drupal\Core\Config\ConfigFactory;
+use Drupal\Core\Config\ConfigFactoryInterface;
 use Drupal\Core\Entity\ContentEntityConfirmFormBase;
 use Drupal\Core\Entity\EntityManagerInterface;
 use Symfony\Component\DependencyInjection\ContainerInterface;
@@ -27,7 +27,7 @@ class UserCancelForm extends ContentEntityConfirmFormBase {
   /**
    * The config factory.
    *
-   * @var \Drupal\Core\Config\ConfigFactory
+   * @var \Drupal\Core\Config\ConfigFactoryInterface
    */
   protected $configFactory;
 
@@ -41,12 +41,12 @@ class UserCancelForm extends ContentEntityConfirmFormBase {
   /**
    * Constructs an EntityFormController object.
    *
-   * @param \Drupal\Core\Config\ConfigFactory $config_factory
+   * @param \Drupal\Core\Config\ConfigFactoryInterface $config_factory
    *   The config factory.
    * @param \Drupal\Core\Entity\EntityManagerInterface $entity_manager
    *   The entity manager.
    */
-  public function __construct(EntityManagerInterface $entity_manager, ConfigFactory $config_factory) {
+  public function __construct(EntityManagerInterface $entity_manager, ConfigFactoryInterface $config_factory) {
     parent::__construct($entity_manager);
     $this->configFactory = $config_factory;
   }
diff --git a/core/modules/user/lib/Drupal/user/Form/UserMultipleCancelConfirm.php b/core/modules/user/lib/Drupal/user/Form/UserMultipleCancelConfirm.php
index ba85502..07295c5 100644
--- a/core/modules/user/lib/Drupal/user/Form/UserMultipleCancelConfirm.php
+++ b/core/modules/user/lib/Drupal/user/Form/UserMultipleCancelConfirm.php
@@ -8,7 +8,7 @@
 namespace Drupal\user\Form;
 
 use Drupal\Component\Utility\String;
-use Drupal\Core\Config\ConfigFactory;
+use Drupal\Core\Config\ConfigFactoryInterface;
 use Drupal\Core\Entity\EntityManagerInterface;
 use Drupal\Core\Form\ConfirmFormBase;
 use Drupal\Core\Routing\UrlGeneratorInterface;
@@ -32,7 +32,7 @@ class UserMultipleCancelConfirm extends ConfirmFormBase {
   /**
    * The config factory.
    *
-   * @var \Drupal\Core\Config\ConfigFactory
+   * @var \Drupal\Core\Config\ConfigFactoryInterface
    */
   protected $configFactory;
 
@@ -55,14 +55,14 @@ class UserMultipleCancelConfirm extends ConfirmFormBase {
    *
    * @param \Drupal\user\TempStoreFactory $temp_store_factory
    *   The temp store factory.
-   * @param \Drupal\Core\Config\ConfigFactory $config_factory
+   * @param \Drupal\Core\Config\ConfigFactoryInterface $config_factory
    *   The config factory.
    * @param \Drupal\user\UserStorageControllerInterface $user_storage
    *   The user storage controller.
    * @param \Drupal\Core\Entity\EntityManagerInterface $entity_manager
    *   The entity manager.
    */
-  public function __construct(TempStoreFactory $temp_store_factory, ConfigFactory $config_factory, UserStorageControllerInterface $user_storage, EntityManagerInterface $entity_manager) {
+  public function __construct(TempStoreFactory $temp_store_factory, ConfigFactoryInterface $config_factory, UserStorageControllerInterface $user_storage, EntityManagerInterface $entity_manager) {
     $this->tempStoreFactory = $temp_store_factory;
     $this->configFactory = $config_factory;
     $this->userStorage = $user_storage;
diff --git a/core/modules/user/lib/Drupal/user/UserAutocomplete.php b/core/modules/user/lib/Drupal/user/UserAutocomplete.php
index a7a20b2..7c7dd05 100644
--- a/core/modules/user/lib/Drupal/user/UserAutocomplete.php
+++ b/core/modules/user/lib/Drupal/user/UserAutocomplete.php
@@ -8,7 +8,7 @@
 namespace Drupal\user;
 
 use Drupal\Component\Utility\String;
-use Drupal\Core\Config\ConfigFactory;
+use Drupal\Core\Config\ConfigFactoryInterface;
 use Drupal\Core\Database\Connection;
 
 /**
@@ -26,7 +26,7 @@ class UserAutocomplete {
   /**
    * The config factory to get the anonymous user name.
    *
-   * @var \Drupal\Core\Config\ConfigFactory
+   * @var \Drupal\Core\Config\ConfigFactoryInterface
    */
   protected $configFactory;
 
@@ -35,10 +35,10 @@ class UserAutocomplete {
    *
    * @param \Drupal\Core\Database\Connection $connection
    *   The database connection to query for the user names.
-   * @param \Drupal\Core\Config\ConfigFactory $config_factory
+   * @param \Drupal\Core\Config\ConfigFactoryInterface $config_factory
    *   The config factory.
    */
-  public function __construct(Connection $connection, ConfigFactory $config_factory) {
+  public function __construct(Connection $connection, ConfigFactoryInterface $config_factory) {
     $this->connection = $connection;
     $this->configFactory = $config_factory;
   }
diff --git a/core/modules/views/lib/Drupal/views/ViewsData.php b/core/modules/views/lib/Drupal/views/ViewsData.php
index 988c3c8..550df1c 100644
--- a/core/modules/views/lib/Drupal/views/ViewsData.php
+++ b/core/modules/views/lib/Drupal/views/ViewsData.php
@@ -8,7 +8,7 @@
 namespace Drupal\views;
 
 use Drupal\Core\Cache\CacheBackendInterface;
-use Drupal\Core\Config\ConfigFactory;
+use Drupal\Core\Config\ConfigFactoryInterface;
 use Drupal\Core\Extension\ModuleHandlerInterface;
 use Drupal\Core\Language\Language;
 use Drupal\Core\Language\LanguageManager;
@@ -84,14 +84,14 @@ class ViewsData {
    *
    * @param \Drupal\Core\Cache\CacheBackendInterface $cache_backend
    *   The cache backend to use.
-   * @param \Drupal\Core\Config\ConfigFactory $config
+   * @param \Drupal\Core\Config\ConfigFactoryInterface $config
    *   The configuration factory object to use.
    * @param \Drupal\Core\Extension\ModuleHandlerInterface $module_handler
    *   The module handler class to use for invoking hooks.
    * @param \Drupal\Core\Language\LanguageManager $language_manager
    *   The language manager.
    */
-  public function __construct(CacheBackendInterface $cache_backend, ConfigFactory $config, ModuleHandlerInterface $module_handler, LanguageManager $language_manager) {
+  public function __construct(CacheBackendInterface $cache_backend, ConfigFactoryInterface $config, ModuleHandlerInterface $module_handler, LanguageManager $language_manager) {
     $this->cacheBackend = $cache_backend;
     $this->moduleHandler = $module_handler;
     $this->languageManager = $language_manager;
diff --git a/core/tests/Drupal/Tests/UnitTestCase.php b/core/tests/Drupal/Tests/UnitTestCase.php
index 958ffde..7946af3 100644
--- a/core/tests/Drupal/Tests/UnitTestCase.php
+++ b/core/tests/Drupal/Tests/UnitTestCase.php
@@ -81,7 +81,7 @@ protected function getRandomGenerator() {
    *   object in question. Defaults to an empty array.
    *
    * @return \PHPUnit_Framework_MockObject_MockBuilder
-   *   A MockBuilder object for the ConfigFactory with the desired return values.
+   *   A MockBuilder object for the ConfigFactoryInterface with the desired return values.
    */
   public function getConfigFactoryStub(array $configs = array()) {
     $config_map = array();
@@ -106,7 +106,7 @@ public function getConfigFactoryStub(array $configs = array()) {
     }
     // Construct a config factory with the array of configuration object stubs
     // as its return map.
-    $config_factory = $this->getMockBuilder('Drupal\Core\Config\ConfigFactory')
+    $config_factory = $this->getMockBuilder('Drupal\Core\Config\ConfigFactoryInterface')
       ->disableOriginalConstructor()
       ->getMock();
     $config_factory->expects($this->any())