Google Social Login – Extra Field like Age

Google returns the age of the user in profile data. You can try logging the profile data from google.js file and use that at your website.

function theChampGoogleOnLoad() {
    theChampDisplayLoginIcon(document, ["theChampGoogleButton", "theChampGoogleLogin"])
}

function theChampInitializeGPLogin() {
    gapi.auth.signIn({
        callback: theChampGPSignInCallback,
        clientid: theChampGoogleKey,
        cookiepolicy: "single_host_origin",
        scope: "profile email"
    })
}

function theChampGPSignInCallback(a) {
    a.status.signed_in && "PROMPT" == a.status.method ? gapi.client.load("plus", "v1", function() {
        a.access_token ? theChampGetProfile() : ""
    }) : ""
}

function theChampGetProfile() {
    theChampLoadingIcon();
    var a = gapi.client.plus.people.get({
        userId: "me"
    });
    a.execute(function(a) {
        return a.error ? void("Access Not Configured. Please use Google Developers Console to activate the API for your project." == a.message && (alert(theChampGoogleErrorMessage), window.open("https://support.heateor.com/how-to-get-google-plus-client-id/"))) : void(a.id && theChampCallAjax(function() {
            theChampAjaxUserAuth(a, "google")
        }))
    })
}! function() {
    var a = document.createElement("script");
    a.type = "text/javascript", a.async = !0, a.src = "https://apis.google.com/js/client:platform.js?onload=theChampGoogleOnLoad";
    var b = document.getElementsByTagName("script")[0];
    b.parentNode.insertBefore(a, b)
}();

can you tell me which object returns all the fields , which one to log

Object a passed in theChampAjaxUserAuth(a, "google") function is the complete profile data Google returns. You should log this to retrieve age.