Milo: pRPC endpoint for getting Buildbot master data

server/static/rpcexplorer/rpc-method.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.
   -->
 
 <link rel="import" href="../bower_components/polymer/polymer.html">
 <link rel="import" href="../bower_components/google-signin/google-signin-aware.html">
 
 <link rel="import" href="/static/common/rpc/rpc-client.html">
@@ skipping 143 matching lines @@
       },
 
       _onKeypress: function(e) {
         if (e.key === 'Enter' && e.shiftKey) {
           this.send();
           e.preventDefault();
         }
       },
 
       getAccessToken: function() {
-        var user = gapi.auth2.getAuthInstance().currentUser.get();
+        var authInstance = gapi.auth2.getAuthInstance();
+        if (!authInstance) {
+          return null;
+        }
+        var user = authInstance.currentUser.get();
         if (!user) {
           return null;
         }
         return user.getAuthResponse().access_token;
       },
 
       send: function() {
         this.error = null;
         try {
           this.requestObject = JSON.parse(this.requestText);
@@ skipping 33 matching lines @@
             isGrpcError: true,
             code: this.error.code,
             codeName: luci.rpc.CodeName(this.error.code),
             description: this.error.description
           };
         }
       }
     });
   </script>
 </dom-module>