diff --git a/core/modules/locale/lib/Drupal/locale/Form/TranslateFilterForm.php b/core/modules/locale/lib/Drupal/locale/Form/TranslateFilterForm.php
index 30a5497..4585602 100644
--- a/core/modules/locale/lib/Drupal/locale/Form/TranslateFilterForm.php
+++ b/core/modules/locale/lib/Drupal/locale/Form/TranslateFilterForm.php
@@ -95,7 +95,7 @@ public function submitForm(array &$form, array &$form_state) {
   }
 
   /**
-   * {@inheritdoc}
+   * Provides a submit handler for the reset button.
    */
   public function resetForm(array &$form, array &$form_state) {
     $_SESSION['locale_translate_filter'] = array();
diff --git a/core/modules/locale/lib/Drupal/locale/Form/TranslateFormBase.php b/core/modules/locale/lib/Drupal/locale/Form/TranslateFormBase.php
index 95d9ca7..717f9d2 100644
--- a/core/modules/locale/lib/Drupal/locale/Form/TranslateFormBase.php
+++ b/core/modules/locale/lib/Drupal/locale/Form/TranslateFormBase.php
@@ -40,14 +40,14 @@
    *
    * @var \Drupal\Core\Language\LanguageManager
    */
-  protected $LanguageManager;
+  protected $languageManager;
 
   /*
-   * Filter values. Shared between objects that inherite this class.
+   * Filter values. Shared between objects that inherit this class.
    *
    * @var array|null
    */
-  public static $filter_values = NULL;
+  protected static $filterValues;
 
   /**
    * Constructs a new TranslationFormBase object.
@@ -59,7 +59,7 @@
    * @param \Drupal\Core\Language\LanguageManager $language_manager
    *   The language manager.
    */
-  public function __construct(StringStorageInterface $locale_storage, KeyValueStore $state, LanguageManager $language_manager) {
+  public function __construct(StringStorageInterface $locale_storage, KeyValueStoreInterface $state, LanguageManager $language_manager) {
     $this->localeStorage = $locale_storage;
     $this->state = $state;
     $this->languageManager = $language_manager;
@@ -79,9 +79,6 @@ public static function create(ContainerInterface $container) {
   /**
    * Builds a string search query and returns an array of string objects.
    *
-   * @param bool $reset
-   *   If the list of values should be reset.
-   *
    * @return array $filter_values
    *   Array of \Drupal\locale\TranslationString objects.
    */
@@ -121,12 +118,15 @@ protected function translateFilterLoadStrings() {
   /**
    * Builds an array out of search criteria specified in request variables.
    *
+   * @param bool $reset
+   *   If the list of values should be reset.
+   *
    * @return array $filter_values
    *   The filter values.
    */
   protected function translateFilterValues($reset = FALSE) {
-    if (!$reset && static::$filter_values) {
-      return static::$filter_values;
+    if (!$reset && static::$filterValues) {
+      return static::$filterValues;
     }
 
     $filter_values = array();
@@ -151,11 +151,11 @@ protected function translateFilterValues($reset = FALSE) {
       }
     }
 
-    return static::$filter_values = $filter_values;
+    return static::$filterValues = $filter_values;
   }
 
   /**
-   * List locale translation filters that can be applied.
+   * Lists locale translation filters that can be applied.
    */
   protected function translateFilters() {
     $filters = array();