diff --git a/core/lib/Drupal/Core/Cache/MemoryBackendFactory.php b/core/lib/Drupal/Core/Cache/MemoryBackendFactory.php
index 7317d39..6783720 100644
--- a/core/lib/Drupal/Core/Cache/MemoryBackendFactory.php
+++ b/core/lib/Drupal/Core/Cache/MemoryBackendFactory.php
@@ -10,49 +10,37 @@
 class MemoryBackendFactory implements CacheFactoryInterface, CacheTagInvalidationInterface {
 
   /**
+   * Instantiated memory cache bins.
+   *
+   * @var \Drupal\Core\Cache\MemoryBackend[]
+   */
+  protected $bins = array();
+
+  /**
    * {@inheritdoc}
    */
   function get($bin) {
-    return new MemoryBackend($bin);
+    if (!isset($this->bins[$bin])) {
+      $this->bins[$bin] = new MemoryBackend($bin);
+    }
+    return $this->bins[$bin];
   }
 
   /**
-   * Deletes items with any of the specified tags.
-   *
-   * If the cache items are being deleted because they are no longer "fresh",
-   * you may consider using invalidateTags() instead. This allows callers to
-   * retrieve the invalid items by calling get() with $allow_invalid set to TRUE.
-   * In some cases an invalid item may be acceptable rather than having to
-   * rebuild the cache.
-   *
-   * @param array $tags
-   *   Associative array of tags, in the same format that is passed to
-   *   CacheBackendInterface::set().
-   *
-   * @see \Drupal\Core\Cache\CacheBackendInterface::set()
-   * @see \Drupal\Core\Cache\CacheTagInvalidationInterface::invalidateTags()
-   * @see \Drupal\Core\Cache\CacheBackendInterface::delete()
-   * @see \Drupal\Core\Cache\CacheBackendInterface::deleteMultiple()
-   * @see \Drupal\Core\Cache\CacheBackendInterface::deleteAll()
+   * {@inheritdoc}
    */
   public function deleteTags(array $tags) {
-    // TODO: Implement deleteTags() method.
+    foreach ($this->bins as $bin) {
+      $bin->deleteTags($tags);
+    }
   }
 
   /**
-   * Marks cache items with any of the specified tags as invalid.
-   *
-   * @param array $tags
-   *   Associative array of tags, in the same format that is passed to
-   *   CacheBackendInterface::set().
-   *
-   * @see \Drupal\Core\Cache\CacheBackendInterface::set()
-   * @see \Drupal\Core\Cache\CacheTagInvalidationInterface::deleteTags()
-   * @see \Drupal\Core\Cache\CacheBackendInterface::invalidate()
-   * @see \Drupal\Core\Cache\CacheBackendInterface::invalidateMultiple()
-   * @see \Drupal\Core\Cache\CacheBackendInterface::invalidateAll()
+   * {@inheritdoc}
    */
   public function invalidateTags(array $tags) {
-    // TODO: Implement invalidateTags() method.
+    foreach ($this->bins as $bin) {
+      $bin->deleteTags($tags);
+    }
   }
 }
diff --git a/core/modules/config/src/Tests/Storage/CachedStorageTest.php b/core/modules/config/src/Tests/Storage/CachedStorageTest.php
index 11c3599..2d4e464 100644
--- a/core/modules/config/src/Tests/Storage/CachedStorageTest.php
+++ b/core/modules/config/src/Tests/Storage/CachedStorageTest.php
@@ -90,7 +90,8 @@ public function containerBuild(ContainerBuilder $container) {
     parent::containerBuild($container);
     // Use the regular database cache backend to aid testing.
     $container->register('cache_factory', 'Drupal\Core\Cache\DatabaseBackendFactory')
-      ->addArgument(new Reference('database'));
+      ->addArgument(new Reference('database'))
+      ->addArgument(new Reference('cache_tag_storage'));
   }
 
 }
diff --git a/core/modules/locale/src/Tests/LocaleTranslationUiTest.php b/core/modules/locale/src/Tests/LocaleTranslationUiTest.php
index e9919cd..1cb8de7 100644
--- a/core/modules/locale/src/Tests/LocaleTranslationUiTest.php
+++ b/core/modules/locale/src/Tests/LocaleTranslationUiTest.php
@@ -137,7 +137,7 @@ public function testStringTranslation() {
 
     // Reset the tag cache on the tester side in order to pick up the call to
     // Cache::deleteTags() on the tested side.
-    drupal_static_reset('Drupal\Core\Cache\CacheBackendInterface::tagCache');
+    drupal_static_reset('Drupal\Core\Cache\DatabaseCacheTagStorage::tagCache');
 
     $this->assertTrue($name != $translation && t($name, array(), array('langcode' => $langcode)) == $translation, 't() works for non-English.');
     // Refresh the locale() cache to get fresh data from t() below. We are in
diff --git a/core/modules/simpletest/src/KernelTestBase.php b/core/modules/simpletest/src/KernelTestBase.php
index f26c5d4..7abd200 100644
--- a/core/modules/simpletest/src/KernelTestBase.php
+++ b/core/modules/simpletest/src/KernelTestBase.php
@@ -256,7 +256,8 @@ public function containerBuild(ContainerBuilder $container) {
     $this->container->setParameter('language.default_values', Language::$defaultValues);
 
     $container->register('lock', 'Drupal\Core\Lock\NullLockBackend');
-    $container->register('cache_factory', 'Drupal\Core\Cache\MemoryBackendFactory');
+    $container->register('cache_factory', 'Drupal\Core\Cache\MemoryBackendFactory')
+      ->addTag('cache_tags');
 
     $container
       ->register('config.storage', 'Drupal\Core\Config\DatabaseStorage')
diff --git a/core/modules/simpletest/src/WebTestBase.php b/core/modules/simpletest/src/WebTestBase.php
index d2b31ae..92d7de9 100644
--- a/core/modules/simpletest/src/WebTestBase.php
+++ b/core/modules/simpletest/src/WebTestBase.php
@@ -1151,9 +1151,9 @@ protected function refreshVariables() {
     // @todo Replace drupal_static() usage within classes and provide a
     //   proper interface for invoking reset() on a cache backend:
     //   https://www.drupal.org/node/2311945.
-    drupal_static_reset('Drupal\Core\Cache\CacheBackendInterface::tagCache');
-    drupal_static_reset('Drupal\Core\Cache\DatabaseBackend::deletedTags');
-    drupal_static_reset('Drupal\Core\Cache\DatabaseBackend::invalidatedTags');
+    drupal_static_reset('Drupal\Core\Cache\DatabaseCacheTagStorage::tagCache');
+    drupal_static_reset('Drupal\Core\Cache\DatabaseCacheTagStorage::deletedTags');
+    drupal_static_reset('Drupal\Core\Cache\DatabaseCacheTagStorage::invalidatedTags');
     foreach (Cache::getBins() as $backend) {
       if (is_callable(array($backend, 'reset'))) {
         $backend->reset();