diff --git a/core/core.services.yml b/core/core.services.yml
index 9e5916c..46517e7 100644
--- a/core/core.services.yml
+++ b/core/core.services.yml
@@ -9,6 +9,7 @@ services:
     arguments: ['@database', '@cache_tag_factory']
   cache.backend.memory:
     class: Drupal\Core\Cache\MemoryBackendFactory
+    arguments: ['@cache_tag_factory']
   cache.bootstrap:
     class: Drupal\Core\Cache\CacheBackendInterface
     tags:
@@ -76,6 +77,12 @@ services:
     arguments: ['@database']
     tags:
       - { name: cache.tag }
+      - { name: persist }
+  cache.tag.memory:
+    class: Drupal\Core\Cache\MemoryTag
+    tags:
+      - { name: cache.tag }
+      - { name: persist }
   config.cachedstorage.storage:
     class: Drupal\Core\Config\FileStorage
     factory_class: Drupal\Core\Config\FileStorageFactory
diff --git a/core/includes/install.core.inc b/core/includes/install.core.inc
index 0b25e59..181606a 100644
--- a/core/includes/install.core.inc
+++ b/core/includes/install.core.inc
@@ -383,6 +383,8 @@ function install_begin_request(&$install_state) {
       ->addArgument(new Reference('event_dispatcher'))
       ->addArgument(new Reference('config.typed'));
 
+    $container->register('cache.tag.memory', 'Drupal\Core\Cache\MemoryTag');
+
     // Register the 'language_manager' service.
     $container->register('language_manager', 'Drupal\Core\Language\LanguageManager')
       ->addArgument(new Reference('language.default'));
@@ -393,6 +395,7 @@ function install_begin_request(&$install_state) {
     foreach (array('bootstrap', 'config', 'cache', 'menu', 'page', 'path') as $bin) {
       $container
         ->register("cache.$bin", 'Drupal\Core\Cache\MemoryBackend')
+        ->addArgument(new Reference('cache.tag.memory'))
         ->addArgument($bin);
     }
 
diff --git a/core/lib/Drupal/Core/Cache/CacheBackendInterface.php b/core/lib/Drupal/Core/Cache/CacheBackendInterface.php
index 0046918..58af9e9 100644
--- a/core/lib/Drupal/Core/Cache/CacheBackendInterface.php
+++ b/core/lib/Drupal/Core/Cache/CacheBackendInterface.php
@@ -186,27 +186,6 @@ public function delete($cid);
   public function deleteMultiple(array $cids);
 
   /**
-   * 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\CacheBackendInterface::invalidateTags()
-   * @see \Drupal\Core\Cache\CacheBackendInterface::delete()
-   * @see \Drupal\Core\Cache\CacheBackendInterface::deleteMultiple()
-   * @see \Drupal\Core\Cache\CacheBackendInterface::deleteAll()
-   */
-  public function deleteTags(array $tags);
-
-  /**
    * Deletes all cache items in a bin.
    *
    * @see \Drupal\Core\Cache\CacheBackendInterface::invalidateAll()
@@ -249,21 +228,6 @@ public function invalidate($cid);
   public function invalidateMultiple(array $cids);
 
   /**
-   * 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\CacheBackendInterface::deleteTags()
-   * @see \Drupal\Core\Cache\CacheBackendInterface::invalidate()
-   * @see \Drupal\Core\Cache\CacheBackendInterface::invalidateMultiple()
-   * @see \Drupal\Core\Cache\CacheBackendInterface::invalidateAll()
-   */
-  public function invalidateTags(array $tags);
-
-  /**
    * Marks all cache items as invalid.
    *
    * Invalid items may be returned in later calls to get(), if the $allow_invalid
diff --git a/core/lib/Drupal/Core/Cache/CacheTagBase.php b/core/lib/Drupal/Core/Cache/CacheTagBase.php
index 006f78d..bfcc211 100644
--- a/core/lib/Drupal/Core/Cache/CacheTagBase.php
+++ b/core/lib/Drupal/Core/Cache/CacheTagBase.php
@@ -13,16 +13,6 @@
 abstract class CacheTagBase implements CacheTagInterface {
 
   /**
-   * {@inheritdoc}
-   */
-  abstract public function invalidateTags(array $tags);
-
-  /**
-   * {@inheritdoc}
-   */
-  abstract public function deleteTags(array $tags);
-
-  /**
    * 'Flattens' a tags array into an array of strings.
    *
    * @param array $tags
diff --git a/core/lib/Drupal/Core/Cache/CacheTagInterface.php b/core/lib/Drupal/Core/Cache/CacheTagInterface.php
index 318e42e..fd09b70 100644
--- a/core/lib/Drupal/Core/Cache/CacheTagInterface.php
+++ b/core/lib/Drupal/Core/Cache/CacheTagInterface.php
@@ -34,4 +34,8 @@ public function deleteTags(array $tags);
    */
   public function invalidateTags(array $tags);
 
+  public function checksumTags(array $tags);
+
+  public function prepareGet(&$item);
+
 }
diff --git a/core/lib/Drupal/Core/Cache/DatabaseBackend.php b/core/lib/Drupal/Core/Cache/DatabaseBackend.php
index d11be9d..d818f67 100644
--- a/core/lib/Drupal/Core/Cache/DatabaseBackend.php
+++ b/core/lib/Drupal/Core/Cache/DatabaseBackend.php
@@ -119,19 +119,17 @@ protected function prepareItem($cache, $allow_invalid) {
 
     $cache->tags = $cache->tags ? explode(' ', $cache->tags) : array();
 
-    $checksum = $this->cacheTag->checksumTags($cache->tags);
+    // Check expire time.
+    $cache->valid = $time_valid = $cache->expire == Cache::PERMANENT || $cache->expire >= REQUEST_TIME;
 
-    // Check if deleteTags() has been called with any of the entry's tags.
-    if ($cache->checksum_deletions != $checksum['deletions']) {
+    $this->cacheTag->prepareGet($cache);
+    if ($cache->deleted) {
+      $this->delete($cache->cid);
       return FALSE;
     }
 
-    // Check expire time.
-    $cache->valid = $cache->expire == Cache::PERMANENT || $cache->expire >= REQUEST_TIME;
-
-    // Check if invalidateTags() has been called with any of the entry's tags.
-    if ($cache->checksum_invalidations != $checksum['invalidations']) {
-      $cache->valid = FALSE;
+    if ($time_valid && !$cache->valid) {
+      $this->invalidate($cache->cid);
     }
 
     if (!$allow_invalid && !$cache->valid) {
@@ -173,8 +171,8 @@ public function set($cid, $data, $expire = Cache::PERMANENT, array $tags = array
    * Actually set the cache.
    */
   protected function doSet($cid, $data, $expire, $tags) {
+    $checksum = $this->cacheTag->checksumTags($tags);
     $flat_tags = $this->cacheTag->flattenTags($tags);
-    $checksum = $this->cacheTag->checksumTags($flat_tags);
     $fields = array(
       'serialized' => 0,
       'created' => REQUEST_TIME,
@@ -229,13 +227,6 @@ public function deleteMultiple(array $cids) {
   }
 
   /**
-   * Implements Drupal\Core\Cache\CacheBackendInterface::deleteTags().
-   */
-  public function deleteTags(array $tags) {
-    $this->cacheTag->deleteTags($tags);
-  }
-
-  /**
    * Implements Drupal\Core\Cache\CacheBackendInterface::deleteAll().
    */
   public function deleteAll() {
@@ -279,13 +270,6 @@ public function invalidateMultiple(array $cids) {
   }
 
   /**
-   * Implements Drupal\Core\Cache\CacheBackendInterface::invalidateTags().
-   */
-  public function invalidateTags(array $tags) {
-    $this->cacheTag->invalidateTags($tags);
-  }
-
-  /**
    * Implements Drupal\Core\Cache\CacheBackendInterface::invalidateAll().
    */
   public function invalidateAll() {
diff --git a/core/lib/Drupal/Core/Cache/DatabaseTag.php b/core/lib/Drupal/Core/Cache/DatabaseTag.php
index 2f3fef3..10f6a9e 100644
--- a/core/lib/Drupal/Core/Cache/DatabaseTag.php
+++ b/core/lib/Drupal/Core/Cache/DatabaseTag.php
@@ -80,14 +80,15 @@ public function deleteTags(array $tags) {
    * Returns the sum total of validations for a given set of tags.
    *
    * @param array $tags
-   *   Array of flat tags.
+   *   Array of tags.
    *
    * @return int
    *   Sum of all invalidations.
    *
    * @see Drupal\Core\Cache\DatabaseBackend::flattenTags()
    */
-  public function checksumTags($flat_tags) {
+  public function checksumTags(array $tags) {
+    $flat_tags = $this->flattenTags($tags);
     $checksum = array(
       'invalidations' => 0,
       'deletions' => 0,
@@ -111,6 +112,21 @@ public function checksumTags($flat_tags) {
   }
 
   /**
+   * {@inheritdoc}
+   */
+  public function prepareGet(&$item) {
+    $checksum = $this->checksumTags($item->tags);
+
+    // Check if deleteTags() has been called with any of the entry's tags.
+    $item->deleted = $item->checksum_deletions != $checksum['deletions'];
+
+    // Check if invalidateTags() has been called with any of the entry's tags.
+    if ($item->checksum_invalidations != $checksum['invalidations']) {
+      $item->valid = FALSE;
+    }
+  }
+
+  /**
    * Act on an exception when cache might be stale.
    *
    * If the cache_tags table does not yet exist, that's fine but if the table
diff --git a/core/lib/Drupal/Core/Cache/MemoryBackend.php b/core/lib/Drupal/Core/Cache/MemoryBackend.php
index a7faca6..261712b 100644
--- a/core/lib/Drupal/Core/Cache/MemoryBackend.php
+++ b/core/lib/Drupal/Core/Cache/MemoryBackend.php
@@ -24,12 +24,20 @@ class MemoryBackend implements CacheBackendInterface {
   protected $cache = array();
 
   /**
+   * The cache tag service.
+   *
+   * @var \Drupal\Core\Cache\CacheTagInterface
+   */
+  protected $cacheTag;
+
+  /**
    * Constructs a MemoryBackend object.
    *
    * @param string $bin
    *   The cache bin for which the object is created.
    */
-  public function __construct($bin) {
+  public function __construct(CacheTagInterface $cache_tag, $bin) {
+    $this->cacheTag = $cache_tag;
   }
 
   /**
@@ -83,7 +91,17 @@ protected function prepareItem($cache, $allow_invalid) {
     }
 
     // Check expire time.
-    $cache->valid = $cache->expire == Cache::PERMANENT || $cache->expire >= REQUEST_TIME;
+    $cache->valid = $time_valid = $cache->expire == Cache::PERMANENT || $cache->expire >= REQUEST_TIME;
+
+    $this->cacheTag->prepareGet($item);
+    if ($cache->deleted) {
+      $this->delete($cache->cid);
+      return FALSE;
+    }
+
+    if ($time_valid && !$cache->valid) {
+      $this->invalidate($cache->cid);
+    }
 
     if (!$allow_invalid && !$cache->valid) {
       return FALSE;
@@ -96,12 +114,15 @@ protected function prepareItem($cache, $allow_invalid) {
    * Implements Drupal\Core\Cache\CacheBackendInterface::set().
    */
   public function set($cid, $data, $expire = Cache::PERMANENT, array $tags = array()) {
+    $checksum = $this->cacheTag->checksumTags($tags);
     $this->cache[$cid] = (object) array(
       'cid' => $cid,
       'data' => $data,
       'created' => REQUEST_TIME,
       'expire' => $expire,
       'tags' => $this->flattenTags($tags),
+      'checksum_invalidations' => $checksum['invalidations'],
+      'checksum_deletions' => $checksum['deletions'],
     );
   }
 
@@ -120,18 +141,6 @@ public function deleteMultiple(array $cids) {
   }
 
   /**
-   * Implements Drupal\Core\Cache\CacheBackendInterface::deleteTags().
-   */
-  public function deleteTags(array $tags) {
-    $flat_tags = $this->flattenTags($tags);
-    foreach ($this->cache as $cid => $item) {
-      if (array_intersect($flat_tags, $item->tags)) {
-        unset($this->cache[$cid]);
-      }
-    }
-  }
-
-  /**
    * Implements Drupal\Core\Cache\CacheBackendInterface::deleteAll().
    */
   public function deleteAll() {
@@ -157,18 +166,6 @@ public function invalidateMultiple(array $cids) {
   }
 
   /**
-   * Implements Drupal\Core\Cache\CacheBackendInterface::invalidateTags().
-   */
-  public function invalidateTags(array $tags) {
-    $flat_tags = $this->flattenTags($tags);
-    foreach ($this->cache as $cid => $item) {
-      if (array_intersect($flat_tags, $item->tags)) {
-        $this->cache[$cid]->expire = REQUEST_TIME - 1;
-      }
-    }
-  }
-
-  /**
    * Implements Drupal\Core\Cache\CacheBackendInterface::invalidateAll().
    */
   public function invalidateAll() {
diff --git a/core/lib/Drupal/Core/Cache/MemoryBackendFactory.php b/core/lib/Drupal/Core/Cache/MemoryBackendFactory.php
index c9e288d..917110d 100644
--- a/core/lib/Drupal/Core/Cache/MemoryBackendFactory.php
+++ b/core/lib/Drupal/Core/Cache/MemoryBackendFactory.php
@@ -10,10 +10,26 @@
 class MemoryBackendFactory implements CacheFactoryInterface {
 
   /**
+   * The cache tag factory service.
+   *
+   * @var \Drupal\Core\Cache\CacheTagFactory
+   */
+  protected $cacheTagFactory;
+
+  /**
+   * Constructs the DatabaseBackendFactory object.
+   *
+   * @param \Drupal\Core\Database\Connection $connection
+   */
+  function __construct(CacheTagFactory $cache_tag_factory) {
+    $this->cacheTagFactory = $cache_tag_factory;
+  }
+
+  /**
    * {@inheritdoc}
    */
   function get($bin) {
-    return new MemoryBackend($bin);
+    return new MemoryBackend($this->cacheTagFactory->get(), $bin);
   }
 
 }
diff --git a/core/lib/Drupal/Core/DependencyInjection/UpdateServiceProvider.php b/core/lib/Drupal/Core/DependencyInjection/UpdateServiceProvider.php
index 4776214..bcf8c06 100644
--- a/core/lib/Drupal/Core/DependencyInjection/UpdateServiceProvider.php
+++ b/core/lib/Drupal/Core/DependencyInjection/UpdateServiceProvider.php
@@ -36,7 +36,8 @@ public function register(ContainerBuilder $container) {
       $container->register('module_handler', 'Drupal\Core\Extension\UpdateModuleHandler')
         ->addArgument('%container.modules%');
       $container
-        ->register('cache_factory', 'Drupal\Core\Cache\MemoryBackendFactory');
+        ->register('cache_factory', 'Drupal\Core\Cache\MemoryBackendFactory')
+        ->addArgument(new Reference('cache_tag_factory'));
       $container
         ->register('router.builder', 'Drupal\Core\Routing\RouteBuilderStatic');
 
diff --git a/core/modules/field/lib/Drupal/field/Entity/FieldInstance.php b/core/modules/field/lib/Drupal/field/Entity/FieldInstance.php
index df4731b..a3cf703 100644
--- a/core/modules/field/lib/Drupal/field/Entity/FieldInstance.php
+++ b/core/modules/field/lib/Drupal/field/Entity/FieldInstance.php
@@ -13,6 +13,7 @@
 use Drupal\field\FieldException;
 use Drupal\Core\TypedData\DataDefinition;
 use Drupal\field\FieldInstanceInterface;
+use Drupal\field\Field as FieldInfo;
 
 /**
  * Defines the Field instance entity.
@@ -249,7 +250,7 @@ public function __construct(array $values, $entity_type = 'field_instance') {
     // Field instances configuration is stored with a 'field_uuid' property
     // unambiguously identifying the field.
     if (isset($values['field_uuid'])) {
-      $field = field_info_field_by_id($values['field_uuid']);
+      $field =  FieldInfo::fieldInfo()->getFieldById($values['field_uuid']);
       if (!$field) {
         throw new FieldException(format_string('Attempt to create an instance of unknown field @uuid', array('@uuid' => $values['field_uuid'])));
       }
diff --git a/core/modules/system/lib/Drupal/system/Tests/Cache/BackendChainUnitTest.php b/core/modules/system/lib/Drupal/system/Tests/Cache/BackendChainUnitTest.php
index 3323b1a..c2207d5 100644
--- a/core/modules/system/lib/Drupal/system/Tests/Cache/BackendChainUnitTest.php
+++ b/core/modules/system/lib/Drupal/system/Tests/Cache/BackendChainUnitTest.php
@@ -9,6 +9,7 @@
 
 use Drupal\Core\Cache\BackendChain;
 use Drupal\Core\Cache\MemoryBackend;
+use Drupal\Core\Cache\MemoryTag;
 
 /**
  * Tests BackendChain using GenericCacheBackendUnitTestBase.
@@ -27,10 +28,11 @@ protected function createCacheBackend($bin) {
     $chain = new BackendChain($bin);
 
     // We need to create some various backends in the chain.
+    $cache_tag = new MemoryTag();
     $chain
-      ->appendBackend(new MemoryBackend('foo'))
-      ->prependBackend(new MemoryBackend('bar'))
-      ->appendBackend(new MemoryBackend('baz'));
+      ->appendBackend(new MemoryBackend($cache_tag, 'foo'))
+      ->prependBackend(new MemoryBackend($cache_tag, 'bar'))
+      ->appendBackend(new MemoryBackend($cache_tag, 'baz'));
 
     return $chain;
   }
diff --git a/core/modules/system/lib/Drupal/system/Tests/Cache/MemoryBackendUnitTest.php b/core/modules/system/lib/Drupal/system/Tests/Cache/MemoryBackendUnitTest.php
index d3a29e3..9ae5488 100644
--- a/core/modules/system/lib/Drupal/system/Tests/Cache/MemoryBackendUnitTest.php
+++ b/core/modules/system/lib/Drupal/system/Tests/Cache/MemoryBackendUnitTest.php
@@ -8,6 +8,7 @@
 namespace Drupal\system\Tests\Cache;
 
 use Drupal\Core\Cache\MemoryBackend;
+use Drupal\Core\Cache\MemoryTag;
 
 /**
  * Tests MemoryBackend using GenericCacheBackendUnitTestBase.
@@ -29,6 +30,6 @@ public static function getInfo() {
    *   A new MemoryBackend object.
    */
   protected function createCacheBackend($bin) {
-    return new MemoryBackend($bin);
+    return new MemoryBackend(new MemoryTag(), $bin);
   }
 }
diff --git a/core/modules/system/lib/Drupal/system/Tests/Plugin/CacheDecoratorTest.php b/core/modules/system/lib/Drupal/system/Tests/Plugin/CacheDecoratorTest.php
index b305d28..a701027 100644
--- a/core/modules/system/lib/Drupal/system/Tests/Plugin/CacheDecoratorTest.php
+++ b/core/modules/system/lib/Drupal/system/Tests/Plugin/CacheDecoratorTest.php
@@ -9,6 +9,7 @@
 
 use Drupal\Core\Cache\MemoryBackendFactory;
 use Drupal\Core\Cache\MemoryBackend;
+use Drupal\Core\Cache\MemoryTag;
 use Drupal\system\Tests\Plugin\Discovery\DiscoveryTestBase;
 use Drupal\Component\Plugin\Discovery\StaticDiscovery;
 use Drupal\Core\Plugin\Discovery\CacheDecorator;
@@ -47,7 +48,7 @@ public function setUp() {
     // Use a non-db cache backend, so that we can use DiscoveryTestBase (which
     // extends UnitTestBase).
     // @todo switch to injecting the MemoryBackend http://drupal.org/node/1903346
-    \Drupal::getContainer()->set("cache.$this->cacheBin", new MemoryBackend($this->cacheBin));
+    \Drupal::getContainer()->set("cache.$this->cacheBin", new MemoryBackend(new MemoryTag(), $this->cacheBin));
 
     // Create discovery objects to test.
     $this->emptyDiscovery = new StaticDiscovery();
diff --git a/core/tests/Drupal/Tests/Core/Cache/BackendChainImplementationUnitTest.php b/core/tests/Drupal/Tests/Core/Cache/BackendChainImplementationUnitTest.php
index 75c0a97..71a5642 100644
--- a/core/tests/Drupal/Tests/Core/Cache/BackendChainImplementationUnitTest.php
+++ b/core/tests/Drupal/Tests/Core/Cache/BackendChainImplementationUnitTest.php
@@ -10,6 +10,7 @@
 use Drupal\Core\Cache\BackendChain;
 use Drupal\Core\Cache\Cache;
 use Drupal\Core\Cache\MemoryBackend;
+use Drupal\Core\Cache\MemoryTag;
 use Drupal\Tests\UnitTestCase;
 
 /**
@@ -59,9 +60,10 @@ public function setUp() {
     parent::setUp();
 
     // Set up three memory backends to be used in the chain.
-    $this->firstBackend = new MemoryBackend('foo');
-    $this->secondBackend = new MemoryBackend('bar');
-    $this->thirdBackend = new MemoryBackend('baz');
+    $cache_tag = new MemoryTag();
+    $this->firstBackend = new MemoryBackend($cache_tag, 'foo');
+    $this->secondBackend = new MemoryBackend($cache_tag, 'bar');
+    $this->thirdBackend = new MemoryBackend($cache_tag, 'baz');
 
     // Set an initial fixed dataset for all testing. The next three data
     // collections will test two edge cases (last backend has the data, and
diff --git a/core/tests/Drupal/Tests/Core/Config/CachedStorageTest.php b/core/tests/Drupal/Tests/Core/Config/CachedStorageTest.php
index 6c60af4..3ad73a1 100644
--- a/core/tests/Drupal/Tests/Core/Config/CachedStorageTest.php
+++ b/core/tests/Drupal/Tests/Core/Config/CachedStorageTest.php
@@ -2,6 +2,7 @@
 
 namespace Drupal\Tests\Core\Config;
 
+use Drupal\Core\Cache\MemoryTag;
 use Drupal\Tests\UnitTestCase;
 use Drupal\Core\Config\CachedStorage;
 use Drupal\Core\Cache\MemoryBackend;
@@ -51,7 +52,7 @@ public function testListAllPrimedPersistentCache() {
     $storage->expects($this->never())->method('listAll');
 
     $response = array("$prefix." . $this->randomName(), "$prefix." . $this->randomName());
-    $cache = new MemoryBackend(__FUNCTION__);
+    $cache = new MemoryBackend(new MemoryTag(), __FUNCTION__);
     $cache->set('find:' . $prefix, $response);
     $cachedStorage = new CachedStorage($storage, $cache);
     $this->assertEquals($response, $cachedStorage->listAll($prefix));
@@ -75,7 +76,7 @@ public function testGetMultipleOnPrimedCache() {
     );
     $storage = $this->getMock('Drupal\Core\Config\StorageInterface');
     $storage->expects($this->never())->method('readMultiple');
-    $cache = new MemoryBackend(__FUNCTION__);
+    $cache = new MemoryBackend(new MemoryTag(), __FUNCTION__);
     foreach ($configCacheValues as $key => $value) {
       $cache->set($key, $value);
     }
@@ -102,7 +103,7 @@ public function testGetMultipleOnPartiallyPrimedCache() {
         'foo' => 'bar',
       ),
     );
-    $cache = new MemoryBackend(__FUNCTION__);
+    $cache = new MemoryBackend(new MemoryTag(), __FUNCTION__);
     foreach ($configCacheValues as $key => $value) {
       $cache->set($key, $value);
     }