LiveChatManager::available

static function available()
{
	if (!is_null(static::$availableCount))
	{
		return static::$availableCount > 0;
	}
	$orm = BitrixImOpenLinesModelLivechatTable::getList(Array(
		'select' => Array('CNT'),
		'runtime' => array(
			new BitrixMainEntityExpressionField('CNT', 'COUNT(*)')
		),
	));
	$row = $orm->fetch();
	static::$availableCount = $row['CNT'];

	return ($row['CNT'] > 0);
}