Fix typo in host_installer.js

remoting/webapp/host_installer.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
  *
  * HostInstaller allows the caller to download the host binary and monitor the
  * install progress of the host by pinging the host periodically via native
  * messaging.
@@ skipping 110 matching lines @@
    * @const
    */
   var CHECK_INSTALL_INTERVAL_IN_MILLISECONDS = 1000;
 
   /** @param {boolean} installed */
   return this.isInstalled().then(function(installed){
     if (installed) {
       return Promise.resolve(true);
     }
 
-    if (that.downloadAndWaitForInstallPromise_ !== null) {
+    if (that.downloadAndWaitForInstallPromise_ === null) {
       that.downloadAndWaitForInstallPromise_ = new Promise(
         /** @param {Function} resolve */
         function(resolve){
           that.download();
           that.checkInstallIntervalId_ = window.setInterval(function() {
             /** @param {boolean} installed */
             that.isInstalled().then(function(installed) {
               if (installed) {
                 that.cancel();
                 resolve();
@@ skipping 11 matching lines @@
  * For example
  *   var promise = hostInstaller.downloadAndWaitForInstall();
  *   hostInstaller.cancel(); // This will prevent |promise| from fulfilling.
  */
 remoting.HostInstaller.prototype.cancel = function() {
   if (this.checkInstallIntervalId_ !== null) {
     window.clearInterval(this.checkInstallIntervalId_);
     this.checkInstallIntervalId_ = null;
   }
   this.downloadAndWaitForInstallPromise_ = null;
-};
+};