Show request headers modifications from browser or other extensions

[Infocatcher]

Example:

Services.obs.addObserver(observer, "http-on-modify-request", false);
setTimeout(function() {
    Services.obs.removeObserver(observer, "http-on-modify-request");
}, 5e3);
function observer(subject, topic, data) {
    if(subject instanceof Components.interfaces.nsIHttpChannel) {
        subject.setRequestHeader("Referer", "https://google.com/", false);
        subject.setRequestHeader("User-Agent", "", false);
        subject.setRequestHeader("X-Test", "test", false);
    }
}

[Infocatcher]

Test for Firefox 3.6 and older (also works in newer versions):

var Services = "Services" in window && window.Services || {
    obs: Components.classes["@mozilla.org/observer-service;1"]
        .getService(Components.interfaces.nsIObserverService)
};
var observer = {
    observe: function(subject, topic, data) {
        if(subject instanceof Components.interfaces.nsIHttpChannel) {
            subject.setRequestHeader("Referer", "https://google.com/", false);
            subject.setRequestHeader("User-Agent", "", false);
            subject.setRequestHeader("X-Test", "test", false);
        }
    }
};
Services.obs.addObserver(observer, "http-on-modify-request", false);
setTimeout(function() {
    Services.obs.removeObserver(observer, "http-on-modify-request");
}, 5e3);

[Infocatcher]

Oh, we also detects Cookie header.

-Show request headers modifications from other extensions
+Show request headers modifications from browser or other extensions

[Infocatcher]

Also added secret extensions.linkPropertiesPlus.showRequestHeadersDiff preference to display changes in diff style.