diff --git a/core/modules/path/lib/Drupal/path/Controller/PathController.php b/core/modules/path/lib/Drupal/path/Controller/PathController.php
index d70c25d..ac7399e 100644
--- a/core/modules/path/lib/Drupal/path/Controller/PathController.php
+++ b/core/modules/path/lib/Drupal/path/Controller/PathController.php
@@ -93,8 +93,8 @@ public function adminOverview($alias = NULL) {
     $header[] = $this->t('Operations');
 
     $query = $this->connection->select('url_alias')
-      ->extend('PagerSelectExtender')
-      ->extend('TableSortExtender');
+      ->extend('Drupal\Core\Database\Query\PagerSelectExtender')
+      ->extend('Drupal\Core\Database\Query\TableSortExtender');
     if ($alias) {
       // Replace wildcards with PDO wildcards.
       $query->condition('alias', '%' . preg_replace('!\*+!', '%', $alias) . '%', 'LIKE');
diff --git a/core/modules/path/lib/Drupal/path/Form/EditForm.php b/core/modules/path/lib/Drupal/path/Form/EditForm.php
index 1520dda..471fcb2 100644
--- a/core/modules/path/lib/Drupal/path/Form/EditForm.php
+++ b/core/modules/path/lib/Drupal/path/Form/EditForm.php
@@ -23,7 +23,7 @@ class EditForm extends FormBase {
   /**
    * The path crud service.
    *
-   * @var Path $path
+   * @var \Drupal\Core\Path\Path;
    */
   protected $path;
 
@@ -51,6 +51,14 @@ class EditForm extends FormBase {
   /**
    * Constructs a \Drupal\Core\Form\FormBase object.
    *
+   * @param \Drupal\Core\Path\Path $path
+   *   The path crud service.
+   * @param \Drupal\Core\Extension\ModuleHandlerInterface $module_handler
+   *   The module handler service.
+   * @param \Drupal\Core\Path\AliasManagerInterface $alias_manager
+   *   The path alias manager service.
+   * @param \Drupal\Core\Routing\UrlGeneratorInterface $url_generator
+   *   The URL generator service.
    */
   public function __construct(Path $path, ModuleHandlerInterface $module_handler, AliasManagerInterface $alias_manager, UrlGeneratorInterface $url_generator) {
     $this->path = $path;
@@ -84,14 +92,12 @@ public function getFormID() {
    *   an alias id for editing or NULL to add a new one.
    */
   public function buildForm(array $form, array &$form_state, $pid = NULL) {
-
-    $pathAlias = $this->path->load(array('pid' => $pid));
-    $form['#title'] = $pathAlias['alias'];
-
+    $path_alias = $this->path->load(array('pid' => $pid));
+    $form['#title'] = $path_alias['alias'];
     $form['source'] = array(
       '#type' => 'textfield',
       '#title' => $this->t('Existing system path'),
-      '#default_value' => $pathAlias['source'],
+      '#default_value' => $path_alias['source'],
       '#maxlength' => 255,
       '#size' => 45,
       '#description' => $this->t('Specify the existing path you wish to alias. For example: node/28, forum/1, taxonomy/term/1.'),
@@ -101,7 +107,7 @@ public function buildForm(array $form, array &$form_state, $pid = NULL) {
     $form['alias'] = array(
       '#type' => 'textfield',
       '#title' => $this->t('Path alias'),
-      '#default_value' => $pathAlias['alias'],
+      '#default_value' => $path_alias['alias'],
       '#maxlength' => 255,
       '#size' => 45,
       '#description' => $this->t('Specify an alternative path by which this data can be accessed. For example, type "about" when writing an about page. Use a relative path and don\'t add a trailing slash or the URL alias won\'t work.'),
@@ -124,7 +130,7 @@ public function buildForm(array $form, array &$form_state, $pid = NULL) {
         '#options' => $language_options,
         '#empty_value' => Language::LANGCODE_NOT_SPECIFIED,
         '#empty_option' => $this->t('- None -'),
-        '#default_value' => $pathAlias['langcode'],
+        '#default_value' => $path_alias['langcode'],
         '#weight' => -10,
         '#description' => $this->t('A path alias set for a specific language will always be used when displaying this page in that language, and takes precedence over path aliases set as <em>- None -</em>.'),
       );
@@ -132,7 +138,7 @@ public function buildForm(array $form, array &$form_state, $pid = NULL) {
     else {
       $form['langcode'] = array(
         '#type' => 'value',
-        '#value' => $pathAlias['langcode']
+        '#value' => $path_alias['langcode']
       );
     }
 
@@ -141,10 +147,10 @@ public function buildForm(array $form, array &$form_state, $pid = NULL) {
       '#type' => 'submit',
       '#value' => $this->t('Save'),
     );
-    if ($pathAlias['pid']) {
+    if ($path_alias['pid']) {
       $form['pid'] = array(
         '#type' => 'hidden',
-        '#value' => $pathAlias['pid'],
+        '#value' => $path_alias['pid'],
       );
       $form['actions']['delete'] = array(
         '#type' => 'submit',
@@ -192,9 +198,10 @@ public function submitForm(array &$form, array &$form_state) {
     $source = &$form_state['values']['source'];
     $source = $this->aliasManager->getSystemPath($source, $langcode);
     $this->path->save($source, $alias, $langcode, $pid);
-    drupal_set_message(t('The alias has been saved.'));
+    drupal_set_message($this->t('The alias has been saved.'));
     $form_state['redirect'] = 'admin/config/search/path';
   }
+
   /**
    * {@inheritdoc}
    */
diff --git a/core/modules/path/lib/Drupal/path/Form/PathAdminFilterForm.php b/core/modules/path/lib/Drupal/path/Form/PathAdminFilterForm.php
index 54caaa4..9c2a6b0 100644
--- a/core/modules/path/lib/Drupal/path/Form/PathAdminFilterForm.php
+++ b/core/modules/path/lib/Drupal/path/Form/PathAdminFilterForm.php
@@ -14,7 +14,6 @@
  */
 class PathAdminFilterForm extends FormBase {
 
-
   /**
    * Form constructor.
    *
@@ -29,10 +28,15 @@ class PathAdminFilterForm extends FormBase {
    *   The form structure.
    */
   public function buildForm(array $form, array &$form_state, $alias = NULL) {
-    $form['#attributes'] = array('class' => array('search-form'));
-    $form['basic'] = array('#type' => 'details',
+    $form['#attributes'] = array(
+      'class' => array('search-form'),
+    );
+    $form['basic'] = array(
+      '#type' => 'details',
       '#title' => $this->t('Filter aliases'),
-      '#attributes' => array('class' => array('container-inline')),
+      '#attributes' => array(
+        'class' => array('container-inline'),
+      ),
     );
     $form['basic']['filter'] = array(
       '#type' => 'search',
@@ -44,11 +48,13 @@ public function buildForm(array $form, array &$form_state, $alias = NULL) {
     );
     $form['basic']['submit'] = array(
       '#type' => 'submit',
+      '#submit' => array(array($this, 'submitFilter')),
       '#value' => $this->t('Filter'),
     );
     if ($alias) {
       $form['basic']['reset'] = array(
         '#type' => 'submit',
+        '#submit' => array(array($this, 'submitReset')),
         '#value' => $this->t('Reset'),
       );
     }
@@ -65,17 +71,27 @@ public function validateForm(array &$form, array &$form_state) {
   }
 
   /**
-   * {@inheritdoc}
+   * Filter Form submission handler.
+   *
+   * @param array $form
+   *   An associative array containing the structure of the form.
+   * @param array $form_state
+   *   An associative array containing the current state of the form.
    */
-  public function submitForm(array &$form, array &$form_state) {
-    $op = $form_state['values']['op'];
-    switch ($op) {
-      case $this->t('Filter'):
-         $_SESSION['path_admin_filter_form'] = trim($form_state['values']['filter']);
-        break;
-      case $this->t('Reset'):
-        $_SESSION['path_admin_filter_form'] = NULL;
-        break;
-    }
+  public function submitFilter(array &$form, array &$form_state) {
+    $_SESSION['path_admin_filter_form'] = trim($form_state['values']['filter']);
   }
+
+  /**
+   * Reset Form submission handler.
+   *
+   * @param array $form
+   *   An associative array containing the structure of the form.
+   * @param array $form_state
+   *   An associative array containing the current state of the form.
+   */
+  public function submitReset(array &$form, array &$form_state) {
+    $_SESSION['path_admin_filter_form'] = NULL;
+  }
+
 }
diff --git a/core/modules/path/lib/Drupal/path/Tests/PathAliasTest.php b/core/modules/path/lib/Drupal/path/Tests/PathAliasTest.php
index 89d82a7..87ca4be 100644
--- a/core/modules/path/lib/Drupal/path/Tests/PathAliasTest.php
+++ b/core/modules/path/lib/Drupal/path/Tests/PathAliasTest.php
@@ -7,9 +7,6 @@
 
 namespace Drupal\path\Tests;
 
-use Drupal\Core\Database\Database;
-use Drupal\Core\Path\AliasWhitelist;
-
 /**
  * Tests path alias functionality.
  */