Trying to get the Request headers from the XHR object, but with no luck, is there a hidden method or property of that object that will expose the headers sent by the browser?

I already know how to set custom request headers and view the response headers, I'm looking to get a list of all REQUEST headers sent, ones created by the browser and my custom ones.

I'm using webkit/chrome, don't care about other browsers.

EDIT: I'm not looking to monitor the request, I'm building a web app and I need to list those headers and display them within the app, please don't tell me about fiddler, firebug and chrome tools, that's not what I'm looking for.