Change record status: 
Project: 
Introduced in branch: 
8.x
Introduced in version: 
dev
Description: 

drupal_anonymous_user() has been replaced by the AnonymousUserSession class.

Drupal 7:

$anonymous_user = drupal_anonymous_user();

Drupal 8:

use Drupal\Core\Session\AnonymousUserSession;
...
$anonymous_user = new AnonymousUserSession();
Impacts: 
Module developers