Improve sign-in error UX.

remoting/webapp/identity.js

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 /**
  * @fileoverview
  * Wrapper class for Chrome's identity API.
  */
 
 'use strict';
@@ skipping 106 matching lines @@
     while (this.pendingCallbacks_.length > 0) {
       var callback = /** @type {remoting.Identity.Callbacks} */
           this.pendingCallbacks_.shift();
       callback.onOk(token);
     }
     return;
   }
 
   // If not, pass an error back to the callback(s) if we've already prompted the
   // user for permission.
-  // TODO(jamiewalch): Figure out what to do with the error in this case.
   if (interactive) {
     console.error(chrome.runtime.lastError);
     while (this.pendingCallbacks_.length > 0) {
       var callback = /** @type {remoting.Identity.Callbacks} */
           this.pendingCallbacks_.shift();
-      callback.onError(remoting.Error.UNEXPECTED);
+      callback.onError(remoting.Error.NOT_AUTHENTICATED);
     }
     return;
   }
 
   // If there's no token, but we haven't yet prompted for permission, do so
   // now. The consent callback is responsible for continuing the auth flow.
   this.consentCallback_(this.onAuthContinue_.bind(this));
 };
 
 /**
@@ skipping 23 matching lines @@
 };
 
 /**
  * Returns whether the web app has authenticated with the Google services.
  *
  * @return {boolean}
  */
 remoting.Identity.prototype.isAuthenticated = function() {
   return remoting.identity.email_ != null;
 };