JavaScript is single-threaded, so there is no need for protecting
against changes to XMLHttpRequest object behind event handler back.
Therefore there is no need for loop that was here in case `xhr' got
new changes while processing current changes. This should make code a
bit more clear.
Signed-off-by: Jakub Narebski <jnareb@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>