CAllCrmActivity::DeleteTask

static function DeleteTask(&$arFields)
{
	$typeID = self::GetActivityType($arFields);
	$associatedEntityID =  isset($arFields['ASSOCIATED_ENTITY_ID']) ? (int)$arFields['ASSOCIATED_ENTITY_ID'] : 0;
	if($typeID !== CCrmActivityType::Task || $associatedEntityID <= 0)
	{
		return false;
	}

	//compatible
	$result = \Bitrix\Crm\Activity\Provider\Task::deleteAssociatedEntity($associatedEntityID, $arFields);
	return $result->isSuccess();
}