Add UI to new botlist to show summary

appengine/swarming/elements/res/imp/common/auth-signin.html

 <!--
   Copyright 2016 The LUCI Authors. All rights reserved.
   Use of this source code is governed under the Apache License, Version 2.0
   that can be found in the LICENSE file.
 
   The `auth-signin` element displays sign-in/sign-out button, user email and
   avatar.
   It has a google-signin/google-signin-aware element under the hood that handles
   the actual OAuth logic.
 
@@ skipping 71 matching lines @@
         clientId: {
           type: String,
         },
         profile: {
           type: Object,
           readOnly: true
         },
         signedIn: {
           type: Boolean,
           readOnly: true,
-          value: false
+          value: false,
+          notify: true,
         }
       },
 
       _onSignin: function(e) {
         this._setSignedIn(true);
         var user = gapi.auth2.getAuthInstance().currentUser.get();
         var profile = user.getBasicProfile();
         this._setProfile({
           email: profile.getEmail(),
           imageUrl: profile.getImageUrl()
         });
         this.set("authResponse", user.getAuthResponse());
+        this._setSignedIn(true);
         this.fire("auth-signin");
       },
 
       _onSignout: function(e) {
         this._setSignedIn(false);
         this._setProfile(null);
       },
 
       _makeHeader: function(authResponse) {
         if (!authResponse) {
           return {};
         }
         return {
           "authorization": authResponse.token_type + " " + authResponse.access_token
         };
       },
 
       signIn: function() {
         this.$.aware.signIn();
       },
 
       signOut: function() {
         this.$.aware.signOut();
       }
     });
   </script>
 </dom-module>