modules/user/views_handler_filter_user_current.inc

<?php

class views_handler_filter_user_current extends views_handler_filter_boolean_operator {
  function construct() {
    parent::construct();
    $this->value_value = t('Is the logged in user');
  }

  function query() {
    $this->ensure_my_table();

    $field = $this->table_alias . '.' . $this->real_field . ' ';
    $or = db_or();

    if (empty($this->value)) {
      $or->condition($field, '***CURRENT_USER***', '<>');
      if ($this->accept_null) {
        $or->isNull($field);
      }
    }
    else {
      $or->condition($field, '***CURRENT_USER***', '=');
    }
    $this->query->add_where($this->options['group'], $or);
  }
}