diff --git a/core/lib/Drupal/Core/Path/MemoryAliasManager.php b/core/lib/Drupal/Core/Path/MemoryAliasManager.php
new file mode 100644
index 0000000..71fc734
--- /dev/null
+++ b/core/lib/Drupal/Core/Path/MemoryAliasManager.php
@@ -0,0 +1,92 @@
+<?php
+
+/**
+ * @file
+ * Contains \Drupal\Core\Path\MemoryAliasManager.
+ */
+
+namespace Drupal\Core\Path;
+
+/**
+ * Defines an alias manager which uses the memory as storage.
+ *
+ * The primary use-cases for this alias manager are tests and 'update.php'.
+ */
+class MemoryAliasManager implements AliasManagerInterface {
+
+  /**
+   * Holds the actual path aliases.
+   *
+   * This array has the langcodes has first level keys and pairs of
+   * path alias and internal paths as values.
+   *
+   * @var array
+   */
+  protected $pathAliasMap = array();
+
+  /**
+   * The default langcode to use when none is specified for path lookups.
+   *
+   * @var string
+   */
+  protected $langcode;
+
+  /**
+   * Constructs a EmemoryAliasManager object.
+   */
+  public function __construct() {
+    $this->langcode = language(LANGUAGE_TYPE_URL)->langcode;
+  }
+
+  /**
+   * Implements \Drupal\Core\Path\AliasManagerInterface::getSystemPath().
+   */
+  public function getSystemPath($path, $path_language = NULL) {
+    $result = $path;
+    $langcode = $path_language ?: $this->langcode;
+
+    // A specific langcode overrides in the not specified case.
+    if (isset($this->pathAliasMap[$langcode][$path])) {
+      $result = $this->pathAliasMap[$langcode][$path];
+    }
+    elseif (isset($this->pathAliasMap[LANGUAGE_NOT_SPECIFIED][$path])) {
+      $result = $this->pathAliasMap[LANGUAGE_NOT_SPECIFIED][$path];
+    }
+    return $result;
+  }
+
+  /**
+   * Implements \Drupal\Core\Path\AliasManagerInterface::getPathAlias().
+   */
+  public function getPathAlias($path, $path_language = NULL) {
+    $result = $path;
+    $langcode = $path_language ?: $this->langcode;
+
+    // @todo Should we store both possible maps to not use arraySearch.
+    // A specific langcode overrides in the not specified case.
+    // array_reverse is used, because newer path aliases should be preferred.
+    if (isset($this->pathAliasMap[$langcode]) && $alias = array_search($path, array_reverse($this->pathAliasMap[$langcode]))) {
+      $result = $alias;
+    }
+    elseif (isset($this->pathAliasMap[LANGUAGE_NOT_SPECIFIED]) && $alias = array_search($path, array_reverse($this->pathAliasMap[LANGUAGE_NOT_SPECIFIED]))) {
+      $result = $alias;
+    }
+    return $result;
+
+  }
+
+  /**
+   * Implements \Drupal\Core\Path\AliasManagerInterface::getPathLookups().
+   */
+  public function getPathLookups() {
+    return $this->pathAliasMap;
+  }
+
+  /**
+   * Implements \Drupal\Core\Path\AliasManagerInterface::preloadPathLookups().
+   */
+  public function preloadPathLookups(array $path_list) {
+    $this->pathAliasMap = $path_list;
+  }
+
+}
diff --git a/core/lib/Drupal/Core/Path/Path.php b/core/lib/Drupal/Core/Path/Path.php
index a7fd55a..4db28a9 100644
--- a/core/lib/Drupal/Core/Path/Path.php
+++ b/core/lib/Drupal/Core/Path/Path.php
@@ -28,14 +28,14 @@ class Path {
    * @param \Drupal\Core\Database\Connection $connection
    *   A database connection for reading and writing path aliases.
    *
-   * @param \Drupal\Core\Path\AliasManager $alias_manager
+   * @param \Drupal\Core\Path\AliasManagerInterface $alias_manager
    *   An alias manager with an internal cache of stored aliases.
    *
    * @todo This class should not take an alias manager in its constructor. Once
    *   we move to firing an event for CRUD operations instead of invoking a
    *   hook, we can have a listener that calls cacheClear() on the alias manager.
    */
-  public function __construct(Connection $connection, AliasManager $alias_manager) {
+  public function __construct(Connection $connection, AliasManagerInterface $alias_manager) {
     $this->connection = $connection;
     $this->alias_manager = $alias_manager;
   }
diff --git a/core/modules/edit/lib/Drupal/edit/Tests/MetadataGeneratorTest.php b/core/modules/edit/lib/Drupal/edit/Tests/MetadataGeneratorTest.php
index a8cec27..ddfba6c 100644
--- a/core/modules/edit/lib/Drupal/edit/Tests/MetadataGeneratorTest.php
+++ b/core/modules/edit/lib/Drupal/edit/Tests/MetadataGeneratorTest.php
@@ -125,7 +125,6 @@ function testSimpleEntityType() {
   }
 
   function testEditorWithCustomMetadata() {
-    $this->installSchema('system', 'url_alias');
     $this->enableModules(array('user', 'filter'));
 
     // Enable edit_test module so that the WYSIWYG Create.js PropertyEditor
diff --git a/core/modules/editor/lib/Drupal/editor/Tests/EditorManagerTest.php b/core/modules/editor/lib/Drupal/editor/Tests/EditorManagerTest.php
index f85f176..7a7c79e 100644
--- a/core/modules/editor/lib/Drupal/editor/Tests/EditorManagerTest.php
+++ b/core/modules/editor/lib/Drupal/editor/Tests/EditorManagerTest.php
@@ -42,7 +42,6 @@ function setUp() {
     parent::setUp();
 
     // Install the Filter module.
-    $this->installSchema('system', 'url_alias');
     $this->enableModules(array('user', 'filter'));
 
     // Add text formats.
diff --git a/core/modules/filter/lib/Drupal/filter/Tests/FilterDefaultConfigTest.php b/core/modules/filter/lib/Drupal/filter/Tests/FilterDefaultConfigTest.php
index fd37fb8..57a2cdb 100644
--- a/core/modules/filter/lib/Drupal/filter/Tests/FilterDefaultConfigTest.php
+++ b/core/modules/filter/lib/Drupal/filter/Tests/FilterDefaultConfigTest.php
@@ -27,8 +27,6 @@ public static function getInfo() {
   function setUp() {
     parent::setUp();
     $this->enableModules(array('user'));
-    // filter_permission() calls into url() to output a link in the description.
-    $this->installSchema('system', 'url_alias');
   }
 
   /**
diff --git a/core/modules/simpletest/lib/Drupal/simpletest/DrupalUnitTestBase.php b/core/modules/simpletest/lib/Drupal/simpletest/DrupalUnitTestBase.php
index b09df75..d1f88cf 100644
--- a/core/modules/simpletest/lib/Drupal/simpletest/DrupalUnitTestBase.php
+++ b/core/modules/simpletest/lib/Drupal/simpletest/DrupalUnitTestBase.php
@@ -154,6 +154,14 @@ public function containerBuild($container) {
         ->register('keyvalue', 'Drupal\Core\KeyValueStore\KeyValueFactory')
         ->addArgument(new Reference('service_container'));
     }
+
+
+    // Register a memory only path alias manager.
+    $container->register('path.alias_manager', 'Drupal\Core\Path\MemoryAliasManager');
+
+    $container->register('path.alias_manager.cached', 'Drupal\Core\CacheDecorator\AliasManagerCacheDecorator')
+      ->addArgument(new Reference('path.alias_manager'))
+      ->addArgument(new Reference('cache.path'));
   }
 
   /**
diff --git a/core/modules/system/lib/Drupal/system/Tests/Path/AliasManagerTestBase.php b/core/modules/system/lib/Drupal/system/Tests/Path/AliasManagerTestBase.php
new file mode 100644
index 0000000..2a3c9ee
--- /dev/null
+++ b/core/modules/system/lib/Drupal/system/Tests/Path/AliasManagerTestBase.php
@@ -0,0 +1,101 @@
+<?php
+
+/**
+ * @file
+ * Definition of Drupal\system\Tests\Path\AliasManagerTestBase.
+ */
+
+namespace Drupal\system\Tests\Path;
+
+use Drupal\Core\Path\AliasManagerInterface;
+use Drupal\Core\Path\MemoryAliasManager;
+use Drupal\simpletest\DrupalUnitTestBase;
+use Drupal\Core\Database\Database;
+use Drupal\Core\Path\Path;
+use Drupal\Core\Path\AliasManager;
+
+/**
+ * Tests path alias CRUD and lookup functionality.
+ */
+abstract class AliasManagerTestBase extends DrupalUnitTestBase {
+
+  /**
+   * Contains the path crud class used by this test.
+   *
+   * @var \Drupal\Core\Path\Path
+   */
+  protected $path;
+
+  /**
+   * Contains the alias manager used by this test.
+   *
+   * @var \Drupal\Core\Path\AliasManagerInterface
+   */
+  protected $aliasManager;
+
+  /**
+   * Tests the alias manager used in the child class.
+   */
+  protected function testLookupPath() {
+    // Test the situation where the source is the same for multiple aliases.
+    // Start with a language-neutral alias, which we will override.
+    $path = array(
+      'source' => "user/1",
+      'alias' => 'foo',
+    );
+
+    $this->path->save($path['source'], $path['alias']);
+    $this->assertEqual($this->aliasManager->getPathAlias($path['source']), $path['alias'], 'Basic alias lookup works.');
+    $this->assertEqual($this->aliasManager->getSystemPath($path['alias']), $path['source'], 'Basic source lookup works.');
+
+    // Create a language specific alias for the default language (English).
+    $path = array(
+      'source' => "user/1",
+      'alias' => "users/Dries",
+      'langcode' => 'en',
+    );
+    $this->path->save($path['source'], $path['alias'], $path['langcode']);
+    $this->assertEqual($this->aliasManager->getPathAlias($path['source']), $path['alias'], 'English alias overrides language-neutral alias.');
+    $this->assertEqual($this->aliasManager->getSystemPath($path['alias']), $path['source'], 'English source overrides language-neutral source.');
+
+    // Create a language-neutral alias for the same path, again.
+    $path = array(
+      'source' => "user/1",
+      'alias' => 'bar',
+    );
+    $this->path->save($path['source'], $path['alias']);
+    $this->assertEqual($this->aliasManager->getPathAlias($path['source']), "users/Dries", 'English alias still returned after entering a language-neutral alias.');
+
+    // Create a language-specific (xx-lolspeak) alias for the same path.
+    $path = array(
+      'source' => "user/1",
+      'alias' => 'LOL',
+      'langcode' => 'xx-lolspeak',
+    );
+    $this->path->save($path['source'], $path['alias'], $path['langcode']);
+    $this->assertEqual($this->aliasManager->getPathAlias($path['source']), "users/Dries", 'English alias still returned after entering a LOLspeak alias.');
+    // The LOLspeak alias should be returned if we really want LOLspeak.
+    $this->assertEqual($this->aliasManager->getPathAlias($path['source'], 'xx-lolspeak'), 'LOL', 'LOLspeak alias returned if we specify xx-lolspeak to the alias manager.');
+
+    // Create a new alias for this path in English, which should override the
+    // previous alias for "user/1".
+    $path = array(
+      'source' => "user/1",
+      'alias' => 'users/my-new-path',
+      'langcode' => 'en',
+    );
+    $this->path->save($path['source'], $path['alias'], $path['langcode']);
+    $this->assertEqual($this->aliasManager->getPathAlias($path['source']), $path['alias'], 'Recently created English alias returned.');
+    $this->assertEqual($this->aliasManager->getSystemPath($path['alias']), $path['source'], 'Recently created English source returned.');
+
+    // Remove the English aliases, which should cause a fallback to the most
+    // recently created language-neutral alias, 'bar'.
+    $this->path->delete(array('langcode' => 'en'));
+    $this->assertEqual($this->aliasManager->getPathAlias($path['source']), 'bar', 'Path lookup falls back to recently created language-neutral alias.');
+
+    // Test the situation where the alias and language are the same, but
+    // the source differs. The newer alias record should be returned.
+    $this->path->save('user/2', 'bar');
+    $this->assertEqual($this->aliasManager->getSystemPath('bar'), 'user/2', 'Newer alias record is returned when comparing two LANGUAGE_NOT_SPECIFIED paths with the same alias.');
+  }
+}
diff --git a/core/modules/system/lib/Drupal/system/Tests/Path/AliasTest.php b/core/modules/system/lib/Drupal/system/Tests/Path/AliasTest.php
index 21a129a..b42937e 100644
--- a/core/modules/system/lib/Drupal/system/Tests/Path/AliasTest.php
+++ b/core/modules/system/lib/Drupal/system/Tests/Path/AliasTest.php
@@ -2,20 +2,33 @@
 
 /**
  * @file
- * Definition of Drupal\system\Tests\Path\CrudTest.
+ * Contains \Drupal\system\Tests\Path\CrudTest.
  */
 
 namespace Drupal\system\Tests\Path;
 
-use Drupal\simpletest\DrupalUnitTestBase;
 use Drupal\Core\Database\Database;
 use Drupal\Core\Path\Path;
 use Drupal\Core\Path\AliasManager;
 
 /**
- * Tests path alias CRUD and lookup functionality.
+ * Tests path alias CRUD and lookup for the database alias manager.
  */
-class AliasTest extends DrupalUnitTestBase {
+class AliasTest extends AliasManagerTestBase {
+
+  /**
+   * Stores a class to generate some example test aliases.
+   *
+   * @var \Drupal\system\Tests\Path\UrlAliasFixtures
+   */
+  protected $fixtures;
+
+  /**
+   * Stores the database connection used by this test.
+   *
+   * @var \Drupal\Core\Database\Connection
+   */
+  protected $connection;
 
   public static function getInfo() {
     return array(
@@ -27,7 +40,18 @@ public static function getInfo() {
 
   public function setUp() {
     parent::setUp();
+
+    // Prepare database.
+    $this->connection = $this->container->get('database');
+
     $this->fixtures = new UrlAliasFixtures();
+    $this->fixtures->createTables($this->connection);
+
+    // In contrast to all other Drupal unit test cases this one uses the alias
+    // manager which uses the database.
+    $keyvalue = $this->container->get('keyvalue');
+    $this->aliasManager = new AliasManager($this->connection, $keyvalue);
+    $this->path = new Path($this->connection, $this->aliasManager);
   }
 
   public function tearDown() {
@@ -36,23 +60,15 @@ public function tearDown() {
     parent::tearDown();
   }
 
-
   function testCRUD() {
-    //Prepare database table.
-    $connection = Database::getConnection();
-    $this->fixtures->createTables($connection);
-
-    //Create AliasManager and Path object.
-    $aliasManager = new AliasManager($connection, $this->container->get('keyvalue'));
-    $path = new Path($connection, $aliasManager);
-
+    // Prepare aliases.
     $aliases = $this->fixtures->sampleUrlAliases();
 
     //Create a few aliases
     foreach ($aliases as $idx => $alias) {
-      $path->save($alias['source'], $alias['alias'], $alias['langcode']);
+      $this->path->save($alias['source'], $alias['alias'], $alias['langcode']);
 
-      $result = $connection->query('SELECT * FROM {url_alias} WHERE source = :source AND alias= :alias AND langcode = :langcode', array(':source' => $alias['source'], ':alias' => $alias['alias'], ':langcode' => $alias['langcode']));
+      $result = $this->connection->query('SELECT * FROM {url_alias} WHERE source = :source AND alias= :alias AND langcode = :langcode', array(':source' => $alias['source'], ':alias' => $alias['alias'], ':langcode' => $alias['langcode']));
       $rows = $result->fetchAll();
 
       $this->assertEqual(count($rows), 1, format_string('Created an entry for %alias.', array('%alias' => $alias['alias'])));
@@ -64,15 +80,15 @@ function testCRUD() {
     //Load a few aliases
     foreach ($aliases as $alias) {
       $pid = $alias['pid'];
-      $loadedAlias = $path->load(array('pid' => $pid));
+      $loadedAlias = $this->path->load(array('pid' => $pid));
       $this->assertEqual($loadedAlias, $alias, format_string('Loaded the expected path with pid %pid.', array('%pid' => $pid)));
     }
 
     //Update a few aliases
     foreach ($aliases as $alias) {
-      $path->save($alias['source'], $alias['alias'] . '_updated', $alias['langcode'], $alias['pid']);
+      $this->path->save($alias['source'], $alias['alias'] . '_updated', $alias['langcode'], $alias['pid']);
 
-      $result = $connection->query('SELECT pid FROM {url_alias} WHERE source = :source AND alias= :alias AND langcode = :langcode', array(':source' => $alias['source'], ':alias' => $alias['alias'] . '_updated', ':langcode' => $alias['langcode']));
+      $result = $this->connection->query('SELECT pid FROM {url_alias} WHERE source = :source AND alias= :alias AND langcode = :langcode', array(':source' => $alias['source'], ':alias' => $alias['alias'] . '_updated', ':langcode' => $alias['langcode']));
       $pid = $result->fetchField();
 
       $this->assertEqual($pid, $alias['pid'], format_string('Updated entry for pid %pid.', array('%pid' => $pid)));
@@ -81,83 +97,13 @@ function testCRUD() {
     //Delete a few aliases
     foreach ($aliases as $alias) {
       $pid = $alias['pid'];
-      $path->delete(array('pid' => $pid));
+      $this->path->delete(array('pid' => $pid));
 
-      $result = $connection->query('SELECT * FROM {url_alias} WHERE pid = :pid', array(':pid' => $pid));
+      $result = $this->connection->query('SELECT * FROM {url_alias} WHERE pid = :pid', array(':pid' => $pid));
       $rows = $result->fetchAll();
 
       $this->assertEqual(count($rows), 0, format_string('Deleted entry with pid %pid.', array('%pid' => $pid)));
     }
   }
 
-  function testLookupPath() {
-    //Prepare database table.
-    $connection = Database::getConnection();
-    $this->fixtures->createTables($connection);
-
-    //Create AliasManager and Path object.
-    $aliasManager = new AliasManager($connection, $this->container->get('keyvalue'));
-    $pathObject = new Path($connection, $aliasManager);
-
-    // Test the situation where the source is the same for multiple aliases.
-    // Start with a language-neutral alias, which we will override.
-    $path = array(
-      'source' => "user/1",
-      'alias' => 'foo',
-    );
-
-    $pathObject->save($path['source'], $path['alias']);
-    $this->assertEqual($aliasManager->getPathAlias($path['source']), $path['alias'], 'Basic alias lookup works.');
-    $this->assertEqual($aliasManager->getSystemPath($path['alias']), $path['source'], 'Basic source lookup works.');
-
-    // Create a language specific alias for the default language (English).
-    $path = array(
-      'source' => "user/1",
-      'alias' => "users/Dries",
-      'langcode' => 'en',
-    );
-    $pathObject->save($path['source'], $path['alias'], $path['langcode']);
-    $this->assertEqual($aliasManager->getPathAlias($path['source']), $path['alias'], 'English alias overrides language-neutral alias.');
-    $this->assertEqual($aliasManager->getSystemPath($path['alias']), $path['source'], 'English source overrides language-neutral source.');
-
-    // Create a language-neutral alias for the same path, again.
-    $path = array(
-      'source' => "user/1",
-      'alias' => 'bar',
-    );
-    $pathObject->save($path['source'], $path['alias']);
-    $this->assertEqual($aliasManager->getPathAlias($path['source']), "users/Dries", 'English alias still returned after entering a language-neutral alias.');
-
-    // Create a language-specific (xx-lolspeak) alias for the same path.
-    $path = array(
-      'source' => "user/1",
-      'alias' => 'LOL',
-      'langcode' => 'xx-lolspeak',
-    );
-    $pathObject->save($path['source'], $path['alias'], $path['langcode']);
-    $this->assertEqual($aliasManager->getPathAlias($path['source']), "users/Dries", 'English alias still returned after entering a LOLspeak alias.');
-    // The LOLspeak alias should be returned if we really want LOLspeak.
-    $this->assertEqual($aliasManager->getPathAlias($path['source'], 'xx-lolspeak'), 'LOL', 'LOLspeak alias returned if we specify xx-lolspeak to the alias manager.');
-
-    // Create a new alias for this path in English, which should override the
-    // previous alias for "user/1".
-    $path = array(
-      'source' => "user/1",
-      'alias' => 'users/my-new-path',
-      'langcode' => 'en',
-    );
-    $pathObject->save($path['source'], $path['alias'], $path['langcode']);
-    $this->assertEqual($aliasManager->getPathAlias($path['source']), $path['alias'], 'Recently created English alias returned.');
-    $this->assertEqual($aliasManager->getSystemPath($path['alias']), $path['source'], 'Recently created English source returned.');
-
-    // Remove the English aliases, which should cause a fallback to the most
-    // recently created language-neutral alias, 'bar'.
-    $pathObject->delete(array('langcode' => 'en'));
-    $this->assertEqual($aliasManager->getPathAlias($path['source']), 'bar', 'Path lookup falls back to recently created language-neutral alias.');
-
-    // Test the situation where the alias and language are the same, but
-    // the source differs. The newer alias record should be returned.
-    $pathObject->save('user/2', 'bar');
-    $this->assertEqual($aliasManager->getSystemPath('bar'), 'user/2', 'Newer alias record is returned when comparing two LANGUAGE_NOT_SPECIFIED paths with the same alias.');
-  }
 }
diff --git a/core/modules/system/lib/Drupal/system/Tests/Path/MemoryAliasTest.php b/core/modules/system/lib/Drupal/system/Tests/Path/MemoryAliasTest.php
new file mode 100644
index 0000000..451cea4
--- /dev/null
+++ b/core/modules/system/lib/Drupal/system/Tests/Path/MemoryAliasTest.php
@@ -0,0 +1,35 @@
+<?php
+
+/**
+ * @file
+ * Contains \Drupal\system\Tests\Path\MemoryAliasTest.
+ */
+
+namespace Drupal\system\Tests\Path;
+
+use Drupal\Core\Path\MemoryAliasManager;
+
+/**
+ * Tests the memory alias manager.
+ *
+ * @see \Drupal\Core\Path\MemoryAliasManager
+ */
+class MemoryAliasTest extends AliasManagerTestBase {
+
+  public static function getInfo() {
+    return array(
+      'name' => t('Memory Path Alias Unit Tests'),
+      'description' => t('Tests the memory path alias manager.'),
+      'group' => t('Path API'),
+    );
+  }
+
+  public function setUp() {
+    parent::setUp();
+
+    // Let the test use the memory alias manager.
+    $this->path = $this->container->get('path.crud');
+    $this->aliasManager = $this->container->get('path.alias_manager');
+  }
+
+}