Handle host need upgrade in Pin browser test

remoting/webapp/browser_test/invalid_pin_browser_test.js

 // Copyright 2014 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
  * @suppress {checkTypes}
  * Browser test for the scenario below:
  * 1. Attempt to connect.
  * 2. Enter |data.pin| at the PIN prompt.
  * 3. Verify that there is connection error due to invalid access code.
  */
 
 'use strict';
 
 /** @constructor */
 browserTest.Invalid_PIN = function() {};
 
 browserTest.Invalid_PIN.prototype.run = function(data) {
   // Input validation.
   browserTest.expect(typeof data.pin == 'string');
 
   // Connect to me2me Host.
-  browserTest.clickOnControl('this-host-connect');
-
-  browserTest.onUIMode(remoting.AppMode.CLIENT_PIN_PROMPT).then(
+  browserTest.connectMe2Me().then(
     this.enterPIN_.bind(this, data.pin)
   ).then(
     // Sleep for two seconds to allow the host backoff timer to reset.
     base.Promise.sleep.bind(window, 2000)
   ).then(function() {
     // On fulfilled.
     browserTest.pass();
   }, function(reason) {
     // On rejected.
     browserTest.fail(reason);
   });
 };
 
 browserTest.Invalid_PIN.prototype.enterPIN_ = function(pin) {
   document.getElementById('pin-entry').value = pin;
   browserTest.clickOnControl('pin-connect-button');
   return browserTest.expectMe2MeError(remoting.Error.INVALID_ACCESS_CODE);
 };