title: Why doesn't firebase javascript authentication work with ie11?
body: <p>I have implemented google authentication on a web page using firebase sdk.</p>
  
  <p>It works fine on chrome, firefox and edge, but on ie11 I get a google authentication page but the authenticated user information is always null.</p>
  
  <p>I think it's supported in ie 11.
  firebase.google.com/support/guides/environments_js-sdk </p>
  
  <p>I added the polyfill by cdn and executed it but it doesn't work. User information is still null.
  unpkg.com/core-js-bundle@3.0.1/minified.js </p>
  
  <p>Why doesn't it only work with ie11?</p>
  
  <pre><code>*function signInGoogle() {
      if (!firebase.auth().currentUser) {
          var provider = new firebase.auth.GoogleAuthProvider();
          provider.addScope('https://www.googleapis.com/auth/plus.login');
          firebase.auth().signInWithRedirect(provider);
      } else {
          firebase.auth().signOut();
      }
  }
  
  function initApp() {
      firebase.auth().getRedirectResult().then(function (result) {
          var user = result.user;
          console.log(user);   // always null 
          if (user) {
              document.getElementById('createForm').submit();
          }
      }).catch(function (error) {
          var errorCode = error.code;
          var errorMessage = error.message;
          var email = error.email;
          var credential = error.credential;
          // [START_EXCLUDE]
          if (errorCode === 'auth/account-exists-with-different-credential') {
              alert('You have already signed up with a different auth provider for that email.');
          } else {
              console.error(error);
          }
      });
  
  }*
  </code></pre>