Customise-AdfsFavicon.js

// From https://gist.github.com/mathiasbynens/428626

document.head || (document.head = document.getElementsByTagName('head')[0]);
function changeFavicon(src) {
    var link = document.createElement('link'),
        oldLink = document.getElementById('dynamic-favicon');
    link.id = 'dynamic-favicon';
    link.rel = 'icon';
    link.href = src;
    if (oldLink) {
     document.head.removeChild(oldLink);
    }
    document.head.appendChild(link);
   }

changeFavicon('/adfs/portal/logo/favicon.ico');