问从firebase注销后从google注销

EN

function auth() {   
    // Initialize Firebase;
    firebase.initializeApp(settings);
    var provider = new firebase.auth.GoogleAuthProvider();

    firebase.auth().signInWithPopup(provider).then(function(result) {
        // This gives you a Google Access Token. You can use it to access the Google API.
        var token = result.credential.accessToken;
        sessionStorage.setItem('tokenK', token);
        // The signed-in user info.
        var user = result.user;
        var tempName = user.displayName.split(" ");
        var fullName = tempName[0].charAt(0).toUpperCase() + tempName[0].toLowerCase().substring(1, tempName[0].length) + 
        " " + tempName[1].charAt(0).toUpperCase() +tempName[1].toLowerCase().substring(1, tempName[1].length);
        sessionStorage.setItem('displayName', fullName);
        sessionStorage.setItem('userName', user.email);
    }).catch(function(error) {
        // Handle Errors here.
        var errorCode = error.code;
        var errorMessage = error.message;
        // The email of the user's account used.
        var email = error.email;
        // The firebase.auth.AuthCredential type that was used.
        var credential = error.credential;
        console.log(error);
    });
}

function logOut(){  
    firebase.initializeApp(settings);
    var dataJ = JSON.stringify(sessionStorage.getItem('userName'));
    var xhttp = new XMLHttpRequest();

    firebase.auth().signOut().then(function() {
        xhttp.onreadystatechange = function() {
            if (this.readyState == 4 && this.status == 204) {
                sessionStorage.removeItem('tokenK');
                sessionStorage.removeItem('displayName');
                sessionStorage.removeItem('userName');
                sessionStorage.removeItem('role');
                sessionStorage.removeItem('school');
                sessionStorage.removeItem('grade');
                window.open('index.html', '_self');                 
            }                   
        };
        xhttp.open("POST", settings.protocol + "://" + settings.host + ":" + settings.port + "/api/Login/SignOut", true);
        xhttp.setRequestHeader("Content-Type", "application/json");
        xhttp.setRequestHeader("Token", sessionStorage.getItem('tokenK'));  
        xhttp.send(dataJ);
    }).catch(function(error) {
        console.log(error);
    }); 
}