diff --git a/core/includes/common.inc b/core/includes/common.inc
index 79b2224..a3d6d66 100644
--- a/core/includes/common.inc
+++ b/core/includes/common.inc
@@ -1058,7 +1058,7 @@ function l($text, $path, array $options = array()) {
     // Add a "data-drupal-link-system-path" attribute to let the
     // drupal.active-link library know the path in a standardized manner.
     if (!isset($variables['options']['attributes']['data-drupal-link-system-path'])) {
-      $variables['options']['attributes']['data-drupal-link-system-path'] = \Drupal::service('path.alias_manager.cached')->getSystemPath($path);
+      $variables['options']['attributes']['data-drupal-link-system-path'] = \Drupal::service('path.alias_manager.cached')->getPathByAlias($path);
     }
   }
 
diff --git a/core/includes/theme.inc b/core/includes/theme.inc
index 8f69720..1e2b35c 100644
--- a/core/includes/theme.inc
+++ b/core/includes/theme.inc
@@ -1230,7 +1230,7 @@ function template_preprocess_links(&$variables) {
 
           // Add a "data-drupal-link-system-path" attribute to let the
           // drupal.active-link library know the path in a standardized manner.
-          $li_attributes['data-drupal-link-system-path'] = \Drupal::service('path.alias_manager.cached')->getSystemPath($path);
+          $li_attributes['data-drupal-link-system-path'] = \Drupal::service('path.alias_manager.cached')->getPathByAlias($path);
         }
 
         $item['link'] = $link_element;
diff --git a/core/lib/Drupal/Core/CacheDecorator/AliasManagerCacheDecorator.php b/core/lib/Drupal/Core/CacheDecorator/AliasManagerCacheDecorator.php
index af48f76..e1b1271 100644
--- a/core/lib/Drupal/Core/CacheDecorator/AliasManagerCacheDecorator.php
+++ b/core/lib/Drupal/Core/CacheDecorator/AliasManagerCacheDecorator.php
@@ -83,25 +83,25 @@ public function writeCache() {
   /**
    * {@inheritdoc}
    */
-  public function getSystemPath($path, $path_language = NULL) {
-    $system_path = $this->aliasManager->getSystemPath($path, $path_language);
+  public function getPathByAlias($alias, $language = NULL) {
+    $path = $this->aliasManager->getPathByAlias($alias, $language);
     // We need to pass on the list of previously cached system paths for this
     // key to the alias manager for use in subsequent lookups.
-    $cached = $this->cache->get($system_path);
+    $cached = $this->cache->get($path);
     $cached_paths = array();
     if ($cached) {
       $cached_paths = $cached->data;
       $this->cacheNeedsWriting = FALSE;
     }
     $this->preloadPathLookups($cached_paths);
-    return $system_path;
+    return $path;
   }
 
   /**
    * {@inheritdoc}
    */
-  public function getPathAlias($path, $path_language = NULL) {
-    return $this->aliasManager->getPathAlias($path, $path_language);
+  public function getAliasByPath($path, $language = NULL) {
+    return $this->aliasManager->getAliasByPath($path, $language);
   }
 
   /**
diff --git a/core/lib/Drupal/Core/Controller/ExceptionController.php b/core/lib/Drupal/Core/Controller/ExceptionController.php
index 12e9cbe..97a1c4f 100644
--- a/core/lib/Drupal/Core/Controller/ExceptionController.php
+++ b/core/lib/Drupal/Core/Controller/ExceptionController.php
@@ -140,7 +140,7 @@ public function on403Html(FlattenException $exception, Request $request) {
     watchdog('access denied', $system_path, NULL, WATCHDOG_WARNING);
 
     $system_config = $this->container->get('config.factory')->get('system.site');
-    $path = $this->container->get('path.alias_manager')->getSystemPath($system_config->get('page.403'));
+    $path = $this->container->get('path.alias_manager')->getPathByAlias($system_config->get('page.403'));
     if ($path && $path != $system_path) {
       if ($request->getMethod() === 'POST') {
         $subrequest = Request::create($request->getBaseUrl() . '/' . $path, 'POST', array('destination' => $system_path, '_exception_statuscode' => 403) + $request->request->all(), $request->cookies->all(), array(), $request->server->all());
@@ -196,7 +196,7 @@ public function on404Html(FlattenException $exception, Request $request) {
 
     $system_path = $request->attributes->get('_system_path');
 
-    $path = $this->container->get('path.alias_manager')->getSystemPath(\Drupal::config('system.site')->get('page.404'));
+    $path = $this->container->get('path.alias_manager')->getPathByAlias(\Drupal::config('system.site')->get('page.404'));
     if ($path && $path != $system_path) {
       // @todo Um, how do I specify an override URL again? Totally not clear. Do
       //   that and sub-call the kernel rather than using meah().
diff --git a/core/lib/Drupal/Core/Path/AliasManager.php b/core/lib/Drupal/Core/Path/AliasManager.php
index 84dbb02..82c19bd 100644
--- a/core/lib/Drupal/Core/Path/AliasManager.php
+++ b/core/lib/Drupal/Core/Path/AliasManager.php
@@ -34,11 +34,11 @@ class AliasManager implements AliasManagerInterface {
   protected $lookupMap = array();
 
   /**
-   * Holds an array of path alias for which no source was found.
+   * Holds an array of aliases for which no path was found.
    *
    * @var array
    */
-  protected $noSource = array();
+  protected $noPath = array();
 
   /**
    * Holds the array of whitelisted path aliases.
@@ -48,18 +48,18 @@ class AliasManager implements AliasManagerInterface {
   protected $whitelist;
 
   /**
-   * Holds an array of system paths that have no aliases.
+   * Holds an array of paths that have no alias.
    *
    * @var array
    */
-  protected $noAliases = array();
+  protected $noAlias = array();
 
   /**
-   * Whether lookupPath() has not yet been called.
+   * Whether preloaded path lookups has already been loaded.
    *
-   * @var boolean
+   * @var array
    */
-  protected $firstLookup = TRUE;
+  protected $languagePreloaded = array();
 
   /**
    * Holds an array of previously looked up paths for the current request path.
@@ -88,36 +88,87 @@ public function __construct(AliasStorageInterface $storage, AliasWhitelistInterf
   }
 
   /**
-   * Implements \Drupal\Core\Path\AliasManagerInterface::getSystemPath().
+   * {@inheritdoc}
    */
-  public function getSystemPath($path, $path_language = NULL) {
+  public function getPathByAlias($alias, $language = NULL) {
     // If no language is explicitly specified we default to the current URL
     // language. If we used a language different from the one conveyed by the
     // requested URL, we might end up being unable to check if there is a path
     // alias matching the URL path.
-    $path_language = $path_language ?: $this->languageManager->getCurrentLanguage(Language::TYPE_URL)->id;
-    // Lookup the path alias first.
-    if (!empty($path) && $source = $this->lookupPathSource($path, $path_language)) {
-      $path = $source;
+    $language = $language ?: $this->languageManager->getCurrentLanguage(Language::TYPE_URL)->id;
+
+    // If we already know that there are no paths for this alias simply return.
+    if (empty($alias) || !empty($this->noPath[$language][$alias])) {
+      return $alias;
     }
 
-    return $path;
+    // Look for the alias within the cached map.
+    if (isset($this->lookupMap[$language]) && ($path = array_search($alias, $this->lookupMap[$language]))) {
+      return $path;
+    }
+
+    // Look for path in storage.
+    if ($path = $this->storage->lookupPathSource($alias, $language)) {
+      $this->lookupMap[$language][$path] = $alias;
+      return $path;
+    }
+
+    // We can't record anything into $this->lookupMap because we didn't find any
+    // paths for this alias. Thus cache to $this->noPath.
+    $this->noPath[$language][$alias] = TRUE;
+    return $alias;
   }
 
   /**
-   * Implements \Drupal\Core\Path\AliasManagerInterface::getPathAlias().
+   * {@inheritdoc}
    */
-  public function getPathAlias($path, $path_language = NULL) {
+  public function getAliasByPath($path, $language = NULL) {
     // If no language is explicitly specified we default to the current URL
     // language. If we used a language different from the one conveyed by the
     // requested URL, we might end up being unable to check if there is a path
     // alias matching the URL path.
-    $path_language = $path_language ?: $this->languageManager->getCurrentLanguage(Language::TYPE_URL)->id;
-    $result = $path;
-    if (!empty($path) && $alias = $this->lookupPathAlias($path, $path_language)) {
-      $result = $alias;
+    $language = $language ?: $this->languageManager->getCurrentLanguage(Language::TYPE_URL)->id;
+
+    // Check the path whitelist, if the top-level part before the first /
+    // is not in the list, then there is no need to do anything further,
+    // it is not in the database.
+    if (empty($path) || !$this->whitelist->get(strtok($path, '/'))) {
+      return $path;
+    }
+
+    // During the first call to this method per language, load the expected
+    // paths for the page from cache.
+    if (empty($this->languagePreloaded[$language])) {
+      $this->languagePreloaded[$language] = TRUE;
+      $this->lookupMap[$language] = array();
+      // Load paths from cache.
+      if (!empty($this->preloadedPathLookups)) {
+        $this->lookupMap[$language] = $this->storage->preloadPathAlias($this->preloadedPathLookups, $language);
+        // Keep a record of paths with no alias to avoid querying twice.
+        $this->noAlias[$language] = array_flip(array_diff_key($this->preloadedPathLookups, array_keys($this->lookupMap[$language])));
+      }
     }
-    return $result;
+
+    // If we already know that there are no aliases for this path simply return.
+    if (!empty($this->noAlias[$language][$path])) {
+      return $path;
+    }
+
+    // If the alias has already been loaded, return it from static cache.
+    if (isset($this->lookupMap[$language][$path])) {
+      return $this->lookupMap[$language][$path];
+    }
+
+    // Try to load alias from storage.
+    if ($alias = $this->storage->lookupPathAlias($path, $language)) {
+      $this->lookupMap[$language][$path] = $alias;
+      return $alias;
+    }
+
+    // We can't record anything into $this->lookupMap because we didn't find any
+    // aliases for this path. Thus cache to $this->noAlias.
+    $this->noAlias[$language][$path] = TRUE;
+    return $path;
   }
 
   /**
@@ -132,9 +183,9 @@ public function cacheClear($source = NULL) {
     else {
       $this->lookupMap = array();
     }
-    $this->noSource = array();
-    $this->no_aliases = array();
-    $this->firstCall = TRUE;
+    $this->noPath = array();
+    $this->noAlias = array();
+    $this->languagePreloaded = array();
     $this->preloadedPathLookups = array();
     $this->pathAliasWhitelistRebuild($source);
   }
@@ -158,86 +209,6 @@ public function preloadPathLookups(array $path_list) {
   }
 
   /**
-   * Given a Drupal system URL return one of its aliases if such a one exists.
-   * Otherwise, return FALSE.
-   *
-   * @param $path
-   *   The path to investigate for corresponding aliases.
-   * @param $langcode
-   *   Optional language code to search the path with. Defaults to the page language.
-   *   If there's no path defined for that language it will search paths without
-   *   language.
-   *
-   * @return
-   *   An aliased path, or FALSE if no path was found.
-   */
-  protected function lookupPathAlias($path, $langcode) {
-    // During the first call to this method per language, load the expected
-    // system paths for the page from cache.
-    if (!empty($this->firstLookup)) {
-      $this->firstLookup = FALSE;
-      $this->lookupMap[$langcode] = array();
-      // Load system paths from cache.
-      if (!empty($this->preloadedPathLookups)) {
-        // Now fetch the aliases corresponding to these system paths.
-        $this->lookupMap[$langcode] = $this->storage->preloadPathAlias($this->preloadedPathLookups, $langcode);
-        // Keep a record of paths with no alias to avoid querying twice.
-        $this->noAliases[$langcode] = array_flip(array_diff_key($this->preloadedPathLookups, array_keys($this->lookupMap[$langcode])));
-      }
-    }
-    // If the alias has already been loaded, return it.
-    if (isset($this->lookupMap[$langcode][$path])) {
-      return $this->lookupMap[$langcode][$path];
-    }
-    // Check the path whitelist, if the top-level part before the first /
-    // is not in the list, then there is no need to do anything further,
-    // it is not in the database.
-    elseif (!$this->whitelist->get(strtok($path, '/'))) {
-      return FALSE;
-    }
-    // For system paths which were not cached, query aliases individually.
-    elseif (!isset($this->noAliases[$langcode][$path])) {
-      $this->lookupMap[$langcode][$path] = $this->storage->lookupPathAlias($path, $langcode);
-      return $this->lookupMap[$langcode][$path];
-    }
-    return FALSE;
-  }
-
-  /**
-   * Given an alias, return its Drupal system URL if one exists. Otherwise,
-   * return FALSE.
-   *
-   * @param $path
-   *   The path to investigate for corresponding system URLs.
-   * @param $langcode
-   *   Optional language code to search the path with. Defaults to the page language.
-   *   If there's no path defined for that language it will search paths without
-   *   language.
-   *
-   * @return
-   *   A Drupal system path, or FALSE if no path was found.
-   */
-  protected function lookupPathSource($path, $langcode) {
-    if ($this->whitelist && !isset($this->noSource[$langcode][$path])) {
-      // Look for the value $path within the cached $map
-      $source = isset($this->lookupMap[$langcode]) ? array_search($path, $this->lookupMap[$langcode]) : FALSE;
-      if (!$source) {
-        if ($source = $this->storage->lookupPathSource($path, $langcode)) {
-          $this->lookupMap[$langcode][$source] = $path;
-        }
-        else {
-          // We can't record anything into $map because we do not have a valid
-          // index and there is no need because we have not learned anything
-          // about any Drupal path. Thus cache to $no_source.
-          $this->noSource[$langcode][$path] = TRUE;
-        }
-      }
-      return $source;
-    }
-    return FALSE;
-  }
-
-  /**
    * Rebuild the path alias white list.
    *
    * @param $source
diff --git a/core/lib/Drupal/Core/Path/AliasManagerInterface.php b/core/lib/Drupal/Core/Path/AliasManagerInterface.php
index 10fe4fa..a8a4544 100644
--- a/core/lib/Drupal/Core/Path/AliasManagerInterface.php
+++ b/core/lib/Drupal/Core/Path/AliasManagerInterface.php
@@ -10,33 +10,30 @@
 interface AliasManagerInterface {
 
   /**
-   * Given a path alias, return the internal path it represents.
+   * Given the alias, return the path it represents.
    *
-   * @param $path
-   *   A Drupal path alias.
-   * @param $path_language
+   * @param string $alias
+   *   An alias.
+   * @param string $language
    *   An optional language code to look up the path in.
    *
-   * @return
-   *   The internal path represented by the alias, or the original alias if no
-   *   internal path was found.
+   * @return string
+   *   The path represented by alias, or the alias if no path was found.
    */
-  public function getSystemPath($path, $path_language = NULL);
+  public function getPathByAlias($alias, $language = NULL);
 
   /**
-   * Given an internal Drupal path, return the alias set by the administrator.
+   * Given a path, return the alias.
    *
-   * @param $path
-   *   An internal Drupal path.
-   *
-   * @param $path_language
+   * @param string $path
+   *   A path.
+   * @param string $language
    *   An optional language code to look up the path in.
    *
-   * @return
-   *   An aliased path if one was found, or the original path if no alias was
-   *   found.
+   * @return string
+   *   An alias that represents the path, or path if no alias was found.
    */
-  public function getPathAlias($path, $path_language = NULL);
+  public function getAliasByPath($path, $language = NULL);
 
   /**
    * Returns an array of system paths that have been looked up.
diff --git a/core/lib/Drupal/Core/PathProcessor/PathProcessorAlias.php b/core/lib/Drupal/Core/PathProcessor/PathProcessorAlias.php
index 66979d1..1c709a1 100644
--- a/core/lib/Drupal/Core/PathProcessor/PathProcessorAlias.php
+++ b/core/lib/Drupal/Core/PathProcessor/PathProcessorAlias.php
@@ -36,7 +36,7 @@ public function __construct(AliasManagerInterface $alias_manager) {
    * Implements Drupal\Core\PathProcessor\InboundPathProcessorInterface::processInbound().
    */
   public function processInbound($path, Request $request) {
-    $path = $this->aliasManager->getSystemPath($path);
+    $path = $this->aliasManager->getPathByAlias($path);
     return $path;
   }
 
@@ -46,7 +46,7 @@ public function processInbound($path, Request $request) {
   public function processOutbound($path, &$options = array(), Request $request = NULL) {
     if (empty($options['alias'])) {
       $langcode = isset($options['language']) ? $options['language']->id : NULL;
-      $path = $this->aliasManager->getPathAlias($path, $langcode);
+      $path = $this->aliasManager->getAliasByPath($path, $langcode);
     }
     return $path;
   }
diff --git a/core/modules/block/lib/Drupal/block/BlockAccessController.php b/core/modules/block/lib/Drupal/block/BlockAccessController.php
index 4f5182b..9e4e472 100644
--- a/core/modules/block/lib/Drupal/block/BlockAccessController.php
+++ b/core/modules/block/lib/Drupal/block/BlockAccessController.php
@@ -98,7 +98,7 @@ protected function checkAccess(EntityInterface $entity, $operation, $langcode, A
       if ($visibility['path']['visibility'] < BLOCK_VISIBILITY_PHP) {
         // Compare the lowercase path alias (if any) and internal path.
         $path = current_path();
-        $path_alias = Unicode::strtolower($this->aliasManager->getPathAlias($path));
+        $path_alias = Unicode::strtolower($this->aliasManager->getAliasByPath($path));
         $page_match = drupal_match_path($path_alias, $pages) || (($path != $path_alias) && drupal_match_path($path, $pages));
         // When $block->visibility has a value of 0
         // (BLOCK_VISIBILITY_NOTLISTED), the block is displayed on all pages
diff --git a/core/modules/link/lib/Drupal/link/Plugin/Field/FieldWidget/LinkWidget.php b/core/modules/link/lib/Drupal/link/Plugin/Field/FieldWidget/LinkWidget.php
index baf1eb5..6550a0e 100644
--- a/core/modules/link/lib/Drupal/link/Plugin/Field/FieldWidget/LinkWidget.php
+++ b/core/modules/link/lib/Drupal/link/Plugin/Field/FieldWidget/LinkWidget.php
@@ -210,7 +210,7 @@ public function massageFormValues(array $values, array $form, array &$form_state
           // If internal links are supported, look up whether the given value is
           // a path alias and store the system path instead.
           if ($this->supportsInternalLinks() && !UrlHelper::isExternal($value['url'])) {
-            $parsed_url['path'] = \Drupal::service('path.alias_manager.cached')->getSystemPath($parsed_url['path']);
+            $parsed_url['path'] = \Drupal::service('path.alias_manager.cached')->getPathByAlias($parsed_url['path']);
           }
 
           $url = Url::createFromPath($parsed_url['path']);
diff --git a/core/modules/locale/lib/Drupal/locale/Tests/LocalePathTest.php b/core/modules/locale/lib/Drupal/locale/Tests/LocalePathTest.php
index 0a3e64b..cae7f4b 100644
--- a/core/modules/locale/lib/Drupal/locale/Tests/LocalePathTest.php
+++ b/core/modules/locale/lib/Drupal/locale/Tests/LocalePathTest.php
@@ -109,10 +109,10 @@ function testPathLanguageConfiguration() {
       'langcode' => Language::LANGCODE_NOT_SPECIFIED,
     );
     $this->container->get('path.alias_storage')->save($edit['source'], $edit['alias'], $edit['langcode']);
-    $lookup_path = $this->container->get('path.alias_manager')->getPathAlias('node/' . $node->id(), 'en');
+    $lookup_path = $this->container->get('path.alias_manager')->getAliasByPath('node/' . $node->id(), 'en');
     $this->assertEqual($english_path, $lookup_path, 'English language alias has priority.');
     // Same check for language 'xx'.
-    $lookup_path = $this->container->get('path.alias_manager')->getPathAlias('node/' . $node->id(), $prefix);
+    $lookup_path = $this->container->get('path.alias_manager')->getAliasByPath('node/' . $node->id(), $prefix);
     $this->assertEqual($custom_language_path, $lookup_path, 'Custom language alias has priority.');
     $this->container->get('path.alias_storage')->delete($edit);
 
diff --git a/core/modules/menu_link/lib/Drupal/menu_link/MenuLinkForm.php b/core/modules/menu_link/lib/Drupal/menu_link/MenuLinkForm.php
index 422906f..5d61123 100644
--- a/core/modules/menu_link/lib/Drupal/menu_link/MenuLinkForm.php
+++ b/core/modules/menu_link/lib/Drupal/menu_link/MenuLinkForm.php
@@ -206,7 +206,7 @@ protected function actions(array $form, array &$form_state) {
   public function validate(array $form, array &$form_state) {
     $menu_link = $this->buildEntity($form, $form_state);
 
-    $normal_path = $this->pathAliasManager->getSystemPath($menu_link->link_path);
+    $normal_path = $this->pathAliasManager->getPathByAlias($menu_link->link_path);
     if ($menu_link->link_path != $normal_path) {
       drupal_set_message(t('The menu system stores system paths only, but will use the URL alias for display. %link_path has been stored as %normal_path', array('%link_path' => $menu_link->link_path, '%normal_path' => $normal_path)));
       $menu_link->link_path = $normal_path;
diff --git a/core/modules/path/lib/Drupal/path/Controller/PathController.php b/core/modules/path/lib/Drupal/path/Controller/PathController.php
index 162bf6e..6144b67 100644
--- a/core/modules/path/lib/Drupal/path/Controller/PathController.php
+++ b/core/modules/path/lib/Drupal/path/Controller/PathController.php
@@ -110,7 +110,7 @@ public function adminOverview($keys) {
 
       // If the system path maps to a different URL alias, highlight this table
       // row to let the user know of old aliases.
-      if ($data->alias != $this->aliasManager->getPathAlias($data->source, $data->langcode)) {
+      if ($data->alias != $this->aliasManager->getAliasByPath($data->source, $data->langcode)) {
         $row['class'] = array('warning');
       }
 
diff --git a/core/modules/path/lib/Drupal/path/Form/PathFormBase.php b/core/modules/path/lib/Drupal/path/Form/PathFormBase.php
index 251fbe3..ca507d1 100644
--- a/core/modules/path/lib/Drupal/path/Form/PathFormBase.php
+++ b/core/modules/path/lib/Drupal/path/Form/PathFormBase.php
@@ -137,7 +137,7 @@ public function buildForm(array $form, array &$form_state, $pid = NULL) {
    */
   public function validateForm(array &$form, array &$form_state) {
     $source = &$form_state['values']['source'];
-    $source = $this->aliasManager->getSystemPath($source);
+    $source = $this->aliasManager->getPathByAlias($source);
     $alias = $form_state['values']['alias'];
     // Language is only set if language.module is enabled, otherwise save for all
     // languages.
@@ -160,7 +160,7 @@ public function submitForm(array &$form, array &$form_state) {
 
     $pid = isset($form_state['values']['pid']) ? $form_state['values']['pid'] : 0;
     $source = &$form_state['values']['source'];
-    $source = $this->aliasManager->getSystemPath($source);
+    $source = $this->aliasManager->getPathByAlias($source);
     $alias = $form_state['values']['alias'];
     // Language is only set if language.module is enabled, otherwise save for all
     // languages.
diff --git a/core/modules/path/lib/Drupal/path/Tests/PathLanguageTest.php b/core/modules/path/lib/Drupal/path/Tests/PathLanguageTest.php
index a2fcbb7..9808705 100644
--- a/core/modules/path/lib/Drupal/path/Tests/PathLanguageTest.php
+++ b/core/modules/path/lib/Drupal/path/Tests/PathLanguageTest.php
@@ -173,17 +173,17 @@ function testAliasTranslation() {
     // The alias manager has an internal path lookup cache. Check to see that
     // it has the appropriate contents at this point.
     $this->container->get('path.alias_manager')->cacheClear();
-    $french_node_path = $this->container->get('path.alias_manager')->getSystemPath($french_alias, 'fr');
+    $french_node_path = $this->container->get('path.alias_manager')->getPathByAlias($french_alias, 'fr');
     $this->assertEqual($french_node_path, 'node/' . $french_node->id(), 'Normal path works.');
     // Second call should return the same path.
-    $french_node_path = $this->container->get('path.alias_manager')->getSystemPath($french_alias, 'fr');
+    $french_node_path = $this->container->get('path.alias_manager')->getPathByAlias($french_alias, 'fr');
     $this->assertEqual($french_node_path, 'node/' . $french_node->id(), 'Normal path is the same.');
 
     // Confirm that the alias works.
-    $french_node_alias = $this->container->get('path.alias_manager')->getPathAlias('node/' . $french_node->id(), 'fr');
+    $french_node_alias = $this->container->get('path.alias_manager')->getAliasByPath('node/' . $french_node->id(), 'fr');
     $this->assertEqual($french_node_alias, $french_alias, 'Alias works.');
     // Second call should return the same alias.
-    $french_node_alias = $this->container->get('path.alias_manager')->getPathAlias('node/' . $french_node->id(), 'fr');
+    $french_node_alias = $this->container->get('path.alias_manager')->getAliasByPath('node/' . $french_node->id(), 'fr');
     $this->assertEqual($french_node_alias, $french_alias, 'Alias is the same.');
   }
 }
diff --git a/core/modules/shortcut/shortcut.module b/core/modules/shortcut/shortcut.module
index 870bd8a..9196fd2 100644
--- a/core/modules/shortcut/shortcut.module
+++ b/core/modules/shortcut/shortcut.module
@@ -273,7 +273,7 @@ function shortcut_set_title_exists($title) {
  */
 function shortcut_valid_link($path) {
   // Do not use URL aliases.
-  $normal_path = \Drupal::service('path.alias_manager')->getSystemPath($path);
+  $normal_path = \Drupal::service('path.alias_manager')->getPathByAlias($path);
   if ($path != $normal_path) {
     $path = $normal_path;
   }
diff --git a/core/modules/shortcut/src/ShortcutPathValue.php b/core/modules/shortcut/src/ShortcutPathValue.php
index 2c8b4e5..3d88d9b 100644
--- a/core/modules/shortcut/src/ShortcutPathValue.php
+++ b/core/modules/shortcut/src/ShortcutPathValue.php
@@ -40,7 +40,7 @@ public function getValue() {
    */
   public function setValue($value, $notify = TRUE) {
     // Normalize the path in case it is an alias.
-    $value = \Drupal::service('path.alias_manager')->getSystemPath($value);
+    $value = \Drupal::service('path.alias_manager')->getPathByAlias($value);
     if (empty($value)) {
       $value = '<front>';
     }
diff --git a/core/modules/shortcut/src/Tests/ShortcutLinksTest.php b/core/modules/shortcut/src/Tests/ShortcutLinksTest.php
index 67f40ad..6607b7f 100644
--- a/core/modules/shortcut/src/Tests/ShortcutLinksTest.php
+++ b/core/modules/shortcut/src/Tests/ShortcutLinksTest.php
@@ -62,7 +62,7 @@ public function testShortcutLinkAdd() {
       $this->assertResponse(200);
       $saved_set = shortcut_set_load($set->id());
       $paths = $this->getShortcutInformation($saved_set, 'path');
-      $this->assertTrue(in_array($this->container->get('path.alias_manager')->getSystemPath($test['path']), $paths), 'Shortcut created: ' . $test['path']);
+      $this->assertTrue(in_array($this->container->get('path.alias_manager')->getPathByAlias($test['path']), $paths), 'Shortcut created: ' . $test['path']);
       $this->assertLink($title, 0, 'Shortcut link found on the page.');
     }
   }
diff --git a/core/modules/statistics/statistics.module b/core/modules/statistics/statistics.module
index 8877181..6a1a416 100644
--- a/core/modules/statistics/statistics.module
+++ b/core/modules/statistics/statistics.module
@@ -169,7 +169,7 @@ function statistics_get($nid) {
  *   A string as a link, truncated to the width, linked to the given $path.
  */
 function _statistics_link($path, $width = 35) {
-  $title = \Drupal::service('path.alias_manager')->getPathAlias($path);
+  $title = \Drupal::service('path.alias_manager')->getAliasByPath($path);
   $title = truncate_utf8($title, $width, FALSE, TRUE);
   return l($title, $path);
 }
diff --git a/core/modules/system/lib/Drupal/system/Form/SiteInformationForm.php b/core/modules/system/lib/Drupal/system/Form/SiteInformationForm.php
index 1a10aaa..79d8df9 100644
--- a/core/modules/system/lib/Drupal/system/Form/SiteInformationForm.php
+++ b/core/modules/system/lib/Drupal/system/Form/SiteInformationForm.php
@@ -94,7 +94,7 @@ public function buildForm(array $form, array &$form_state) {
       '#title' => t('Front page'),
       '#open' => TRUE,
     );
-    $front_page = $site_config->get('page.front') != 'user' ? $this->aliasManager->getPathAlias($site_config->get('page.front')) : '';
+    $front_page = $site_config->get('page.front') != 'user' ? $this->aliasManager->getAliasByPath($site_config->get('page.front')) : '';
     $form['front_page']['site_frontpage'] = array(
       '#type' => 'textfield',
       '#title' => t('Default front page'),
@@ -139,7 +139,7 @@ public function validateForm(array &$form, array &$form_state) {
     }
     else {
       // Get the normal path of the front page.
-      form_set_value($form['front_page']['site_frontpage'], $this->aliasManager->getSystemPath($form_state['values']['site_frontpage']), $form_state);
+      form_set_value($form['front_page']['site_frontpage'], $this->aliasManager->getPathByAlias($form_state['values']['site_frontpage']), $form_state);
     }
     // Validate front page path.
     if (!drupal_valid_path($form_state['values']['site_frontpage'])) {
@@ -147,10 +147,10 @@ public function validateForm(array &$form, array &$form_state) {
     }
     // Get the normal paths of both error pages.
     if (!empty($form_state['values']['site_403'])) {
-      form_set_value($form['error_page']['site_403'], $this->aliasManager->getSystemPath($form_state['values']['site_403']), $form_state);
+      form_set_value($form['error_page']['site_403'], $this->aliasManager->getPathByAlias($form_state['values']['site_403']), $form_state);
     }
     if (!empty($form_state['values']['site_404'])) {
-      form_set_value($form['error_page']['site_404'], $this->aliasManager->getSystemPath($form_state['values']['site_404']), $form_state);
+      form_set_value($form['error_page']['site_404'], $this->aliasManager->getPathByAlias($form_state['values']['site_404']), $form_state);
     }
     // Validate 403 error path.
     if (!empty($form_state['values']['site_403']) && !drupal_valid_path($form_state['values']['site_403'])) {
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 07bf006..0baae45 100644
--- a/core/modules/system/lib/Drupal/system/Tests/Path/AliasTest.php
+++ b/core/modules/system/lib/Drupal/system/Tests/Path/AliasTest.php
@@ -95,8 +95,8 @@ function testLookupPath() {
     );
 
     $aliasStorage->save($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.');
+    $this->assertEqual($aliasManager->getAliasByPath($path['source']), $path['alias'], 'Basic alias lookup works.');
+    $this->assertEqual($aliasManager->getPathByAlias($path['alias']), $path['source'], 'Basic source lookup works.');
 
     // Create a language specific alias for the default language (English).
     $path = array(
@@ -107,8 +107,8 @@ function testLookupPath() {
     $aliasStorage->save($path['source'], $path['alias'], $path['langcode']);
     // Hook that clears cache is not executed with unit tests.
     \Drupal::service('path.alias_manager.cached')->cacheClear();
-    $this->assertEqual($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.');
+    $this->assertEqual($aliasManager->getAliasByPath($path['source']), $path['alias'], 'English alias overrides language-neutral alias.');
+    $this->assertEqual($aliasManager->getPathByAlias($path['alias']), $path['source'], 'English source overrides language-neutral source.');
 
     // Create a language-neutral alias for the same path, again.
     $path = array(
@@ -116,7 +116,7 @@ function testLookupPath() {
       'alias' => 'bar',
     );
     $aliasStorage->save($path['source'], $path['alias']);
-    $this->assertEqual($aliasManager->getPathAlias($path['source']), "users/Dries", 'English alias still returned after entering a language-neutral alias.');
+    $this->assertEqual($aliasManager->getAliasByPath($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(
@@ -125,9 +125,9 @@ function testLookupPath() {
       'langcode' => 'xx-lolspeak',
     );
     $aliasStorage->save($path['source'], $path['alias'], $path['langcode']);
-    $this->assertEqual($aliasManager->getPathAlias($path['source']), "users/Dries", 'English alias still returned after entering a LOLspeak alias.');
+    $this->assertEqual($aliasManager->getAliasByPath($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.');
+    $this->assertEqual($aliasManager->getAliasByPath($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".
@@ -139,22 +139,22 @@ function testLookupPath() {
     $aliasStorage->save($path['source'], $path['alias'], $path['langcode']);
     // Hook that clears cache is not executed with unit tests.
     $aliasManager->cacheClear();
-    $this->assertEqual($aliasManager->getPathAlias($path['source']), $path['alias'], 'Recently created English alias returned.');
-    $this->assertEqual($aliasManager->getSystemPath($path['alias']), $path['source'], 'Recently created English source returned.');
+    $this->assertEqual($aliasManager->getAliasByPath($path['source']), $path['alias'], 'Recently created English alias returned.');
+    $this->assertEqual($aliasManager->getPathByAlias($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'.
     $aliasStorage->delete(array('langcode' => 'en'));
     // Hook that clears cache is not executed with unit tests.
     $aliasManager->cacheClear();
-    $this->assertEqual($aliasManager->getPathAlias($path['source']), 'bar', 'Path lookup falls back to recently created language-neutral alias.');
+    $this->assertEqual($aliasManager->getAliasByPath($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.
     $aliasStorage->save('user/2', 'bar');
     // Hook that clears cache is not executed with unit tests.
     $aliasManager->cacheClear();
-    $this->assertEqual($aliasManager->getSystemPath('bar'), 'user/2', 'Newer alias record is returned when comparing two Language::LANGCODE_NOT_SPECIFIED paths with the same alias.');
+    $this->assertEqual($aliasManager->getPathByAlias('bar'), 'user/2', 'Newer alias record is returned when comparing two Language::LANGCODE_NOT_SPECIFIED paths with the same alias.');
   }
 
   /**
diff --git a/core/modules/system/lib/Drupal/system/Tests/Path/UrlAlterFunctionalTest.php b/core/modules/system/lib/Drupal/system/Tests/Path/UrlAlterFunctionalTest.php
index 5772e0a..4924408 100644
--- a/core/modules/system/lib/Drupal/system/Tests/Path/UrlAlterFunctionalTest.php
+++ b/core/modules/system/lib/Drupal/system/Tests/Path/UrlAlterFunctionalTest.php
@@ -119,7 +119,7 @@ protected function assertUrlOutboundAlter($original, $final) {
    */
   protected function assertUrlInboundAlter($original, $final) {
     // Test inbound altering.
-    $result = $this->container->get('path.alias_manager')->getSystemPath($original);
+    $result = $this->container->get('path.alias_manager')->getPathByAlias($original);
     $this->assertIdentical($result, $final, format_string('Altered inbound URL %original, expected %final, and got %result.', array('%original' => $original, '%final' => $final, '%result' => $result)));
   }
 }
diff --git a/core/modules/system/lib/Drupal/system/Tests/Routing/MockAliasManager.php b/core/modules/system/lib/Drupal/system/Tests/Routing/MockAliasManager.php
index 3d8d737..59b7f18 100644
--- a/core/modules/system/lib/Drupal/system/Tests/Routing/MockAliasManager.php
+++ b/core/modules/system/lib/Drupal/system/Tests/Routing/MockAliasManager.php
@@ -62,16 +62,19 @@ public function addAlias($path, $alias, $path_language = NULL) {
   /**
    * {@inheritdoc}
    */
-  public function getSystemPath($path, $path_language = NULL) {
-    $language = $path_language ?: $this->defaultLanguage;
-    return $this->systemPaths[$path][$language];
+  public function getPathByAlias($alias, $language = NULL) {
+    $language = $language ?: $this->defaultLanguage;
+    return $this->systemPaths[$alias][$language];
   }
 
   /**
    * {@inheritdoc}
+   * @param $path
+   * @param null $language
+   * @return
    */
-  public function getPathAlias($path, $path_language = NULL) {
-    $language = $path_language ?: $this->defaultLanguage;
+  public function getAliasByPath($path, $language = NULL) {
+    $language = $language ?: $this->defaultLanguage;
     $this->lookedUp[$path] = 1;
     return $this->aliases[$path][$language];
   }
diff --git a/core/modules/views/lib/Drupal/views/Plugin/views/argument_default/Raw.php b/core/modules/views/lib/Drupal/views/Plugin/views/argument_default/Raw.php
index 5f8a349..3f144ae 100644
--- a/core/modules/views/lib/Drupal/views/Plugin/views/argument_default/Raw.php
+++ b/core/modules/views/lib/Drupal/views/Plugin/views/argument_default/Raw.php
@@ -101,7 +101,7 @@ public function buildOptionsForm(&$form, &$form_state) {
   public function getArgument() {
     $path = $this->request->attributes->get('_system_path');
     if ($this->options['use_alias']) {
-      $path = $this->aliasManager->getPathAlias($path);
+      $path = $this->aliasManager->getAliasByPath($path);
     }
     $args = explode('/', $path);
     if (isset($args[$this->options['index']])) {
diff --git a/core/modules/views/tests/Drupal/views/Tests/Plugin/argument_default/RawTest.php b/core/modules/views/tests/Drupal/views/Tests/Plugin/argument_default/RawTest.php
index af285f9..397cb36 100644
--- a/core/modules/views/tests/Drupal/views/Tests/Plugin/argument_default/RawTest.php
+++ b/core/modules/views/tests/Drupal/views/Tests/Plugin/argument_default/RawTest.php
@@ -42,7 +42,7 @@ public function testGetArgument() {
     $request = new Request(array(), array(), array('_system_path' => 'test/example'));
     $alias_manager = $this->getMock('Drupal\Core\Path\AliasManagerInterface');
     $alias_manager->expects($this->never())
-      ->method('getPathAlias');
+      ->method('getAliasByPath');
 
     // Don't use aliases.
     $raw = new Raw(array(), 'raw', array(), $request, $alias_manager);
@@ -64,7 +64,7 @@ public function testGetArgument() {
     // Setup an alias manager with a path alias.
     $alias_manager = $this->getMock('Drupal\Core\Path\AliasManagerInterface');
     $alias_manager->expects($this->any())
-      ->method('getPathAlias')
+      ->method('getAliasByPath')
       ->with($this->equalTo('test/example'))
       ->will($this->returnValue('other/example'));
 
diff --git a/core/modules/views_ui/views_ui.module b/core/modules/views_ui/views_ui.module
index b1c3437..a8cdfd5 100644
--- a/core/modules/views_ui/views_ui.module
+++ b/core/modules/views_ui/views_ui.module
@@ -320,7 +320,7 @@ function views_ui_views_analyze(ViewExecutable $view) {
       continue;
     }
     if ($display->hasPath() && $path = $display->getOption('path')) {
-      $normal_path = \Drupal::service('path.alias_manager.cached')->getSystemPath($path);
+      $normal_path = \Drupal::service('path.alias_manager.cached')->getPathByAlias($path);
       if ($path != $normal_path) {
         $ret[] = Analyzer::formatMessage(t('You have configured display %display with a path which is an path alias as well. This might lead to unwanted effects so better use an internal path.', array('%display' => $display->display['display_title'])), 'warning');
       }
diff --git a/core/tests/Drupal/Tests/Core/Entity/EntityUrlTest.php b/core/tests/Drupal/Tests/Core/Entity/EntityUrlTest.php
index c25be20..2ff0bf7 100644
--- a/core/tests/Drupal/Tests/Core/Entity/EntityUrlTest.php
+++ b/core/tests/Drupal/Tests/Core/Entity/EntityUrlTest.php
@@ -251,9 +251,9 @@ public function testUrlForAdminForm() {
   }
 
   /**
-   * Tests the getSystemPath() method.
+   * Tests the getPathByAlias() method.
    *
-   * @covers ::getSystemPath()
+   * @covers ::getPathByAlias()
    */
   public function testGetSystemPath() {
     $entity_type = $this->getMock('Drupal\Core\Entity\EntityTypeInterface');
diff --git a/core/tests/Drupal/Tests/Core/PathProcessor/PathProcessorAliasTest.php b/core/tests/Drupal/Tests/Core/PathProcessor/PathProcessorAliasTest.php
index 40c8de0..d810d1c 100644
--- a/core/tests/Drupal/Tests/Core/PathProcessor/PathProcessorAliasTest.php
+++ b/core/tests/Drupal/Tests/Core/PathProcessor/PathProcessorAliasTest.php
@@ -54,7 +54,7 @@ protected function setUp() {
    */
   public function testProcessInbound() {
     $this->aliasManager->expects($this->exactly(2))
-      ->method('getSystemPath')
+      ->method('getPathByAlias')
       ->will($this->returnValueMap(array(
         array('urlalias', NULL, 'internal-url'),
         array('url', NULL, 'url'),
@@ -73,7 +73,7 @@ public function testProcessInbound() {
    */
   public function testProcessOutbound() {
     $this->aliasManager->expects($this->exactly(2))
-      ->method('getPathAlias')
+      ->method('getAliasByPath')
       ->will($this->returnValueMap(array(
         array('internal-url', NULL, 'urlalias'),
         array('url', NULL, 'url'),
diff --git a/core/tests/Drupal/Tests/Core/PathProcessor/PathProcessorTest.php b/core/tests/Drupal/Tests/Core/PathProcessor/PathProcessorTest.php
index 8f877f7..f58edc5 100644
--- a/core/tests/Drupal/Tests/Core/PathProcessor/PathProcessorTest.php
+++ b/core/tests/Drupal/Tests/Core/PathProcessor/PathProcessorTest.php
@@ -110,7 +110,7 @@ function testProcessInbound() {
     );
 
     $alias_manager->expects($this->any())
-      ->method('getSystemPath')
+      ->method('getPathByAlias')
       ->will($this->returnValueMap($system_path_map));
 
     // Create a stub config factory with all config settings that will be checked
diff --git a/core/tests/Drupal/Tests/Core/Routing/UrlGeneratorTest.php b/core/tests/Drupal/Tests/Core/Routing/UrlGeneratorTest.php
index 151b749..5226261 100644
--- a/core/tests/Drupal/Tests/Core/Routing/UrlGeneratorTest.php
+++ b/core/tests/Drupal/Tests/Core/Routing/UrlGeneratorTest.php
@@ -115,7 +115,7 @@ function setUp() {
       ->getMock();
 
     $alias_manager->expects($this->any())
-      ->method('getPathAlias')
+      ->method('getAliasByPath')
       ->will($this->returnCallback(array($this, 'aliasManagerCallback')));
 
     $this->aliasManager = $alias_manager;
@@ -144,11 +144,12 @@ function setUp() {
   }
 
   /**
-   * Return value callback for the getPathAlias() method on the mock alias manager.
+   * Return value callback for the getAliasByPath() method on the mock alias
+   * manager.
    *
-   * Ensures that by default the call to getPathAlias() will return the first argument
-   * that was passed in. We special-case the paths for which we wish it to return an
-   * actual alias.
+   * Ensures that by default the call to getAliasByPath() will return the first
+   * argument that was passed in. We special-case the paths for which we wish it
+   * to return an actual alias.
    *
    * @return string
    */