Incorrect documentation, param and code example for hook_element_info_alter() in theme.inc

The correct param is $info.

/**
 * Alter the element type information returned from modules.
 *
 * A module may implement this hook in order to alter the element type defaults
 * defined by a module.
 *
 * @param array $types
 *   An associative array with structure identical to that of the return value
 *   of \Drupal\Core\Render\ElementInfoManagerInterface::getInfo().
 *
 * @see \Drupal\Core\Render\ElementInfoManager
 * @see \Drupal\Core\Render\Element\ElementInterface
 */
function hook_element_info_alter(array &$types) {
  // Decrease the default size of textfields.
  if (isset($types['textfield']['#size'])) {
    $types['textfield']['#size'] = 40;
  }
}

Perhaps we can use the code example from the test:
http://cgit.drupalcode.org/drupal/tree/core/modules/system/tests/themes/...