Demostration on how to measure the XmlHttpRequest completion times using JavaScript, globally, made by any JavaScript library (jQuery etc.)
This small piece of code wraps the XmlHttpRequest object methods with code that will measure the time difference between the events that occur in the life of the XmlHttpRequest object.
http://52.28.28.50/xhrmeasure/test.html
XHRMeasure is a free software distributed under the terms of the MIT license