Update to drupal-org-drupal 8.0.0-rc2. For more information, see https://www.drupal.org/node/2598668

core/lib/Drupal/Core/StringTranslation/StringTranslationTrait.php

@@ -56,17 +56,6 @@ trait StringTranslationTrait {
     return $this->getStringTranslation()->formatPlural($count, $singular, $plural, $args, $options);
   }
 
-  /**
-   * Formats a translated string containing a count of items.
-   *
-   * See the
-   * \Drupal\Core\StringTranslation\TranslationInterface::formatPluralTranslated()
-   * documentation for details.
-   */
-  protected function formatPluralTranslated($count, $translated, array $args = array(), array $options = array()) {
-    return $this->getStringTranslation()->formatPluralTranslated($count, $translated, $args, $options);
-  }
-
   /**
    * Returns the number of plurals supported by a given language.
    *

core/lib/Drupal/Core/StringTranslation/TranslationManager.php

@@ -7,7 +7,6 @@
 
 namespace Drupal\Core\StringTranslation;
 
-use Drupal\Component\Utility\SafeMarkup;
 use Drupal\Core\Language\LanguageDefault;
 use Drupal\Core\StringTranslation\Translator\TranslatorInterface;