class Permission

AccessPermissionTest.php in drupal/core/modules/user/lib/Drupal/user/Tests/Views/AccessPermissionTest.php

Contains \Drupal\user\Tests\Views\AccessPermissionTest.

Permission::buildOptionsForm in drupal/core/modules/user/lib/Drupal/user/Plugin/views/access/Permission.php

Provide the default form for setting options.

theme_user_admin_permissions in drupal/core/modules/user/user.admin.inc

Returns HTML for the administer permissions page.

user_views_data in drupal/core/modules/user/user.views.inc

Implements hook_views_data().

views.access.schema.yml in drupal/core/modules/views/config/schema/views.access.schema.yml

drupal/core/modules/views/config/schema/views.access.schema.yml

views.view.user_admin_people.yml in drupal/core/modules/user/config/views.view.user_admin_people.yml

drupal/core/modules/user/config/views.view.user_admin_people.yml

class Permission extends AccessPluginBase {

  /**
   * Overrides Drupal\views\Plugin\Plugin::$usesOptions.
   */
  protected $usesOptions = TRUE;

  /**
   * {@inheritdoc}
   */
  public function access(AccountInterface $account) {
    return user_access($this->options['perm'], $account) || user_access('access all views', $account);
  }

  /**
   * {@inheritdoc}
   */
  public function alterRouteDefinition(Route $route) {
    $route
      ->setRequirement('_permission', $this->options['perm']);
  }
  public function summaryTitle() {
    $permissions = module_invoke_all('permission');
    if (isset($permissions[$this->options['perm']])) {
      return $permissions[$this->options['perm']]['title'];
    }
    return t($this->options['perm']);
  }
  protected function defineOptions() {
    $options = parent::defineOptions();
    $options['perm'] = array(
      'default' => 'access content',
    );
    return $options;
  }
  public function buildOptionsForm(&$form, &$form_state) {
    parent::buildOptionsForm($form, $form_state);
    $perms = array();
    $module_info = system_get_info('module');

    // Get list of permissions
    foreach (module_implements('permission') as $module) {
      $permissions = module_invoke($module, 'permission');
      foreach ($permissions as $name => $perm) {
        $perms[$module_info[$module]['name']][$name] = strip_tags($perm['title']);
      }
    }
    ksort($perms);
    $form['perm'] = array(
      '#type' => 'select',
      '#options' => $perms,
      '#title' => t('Permission'),
      '#default_value' => $this->options['perm'],
      '#description' => t('Only users with the selected permission flag will be able to access this display. Note that users with "access all views" can see any view, regardless of other permissions.'),
    );
  }

}