Random clean up around Chrome OS file manager code.

ui/file_manager/gallery/js/background.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.
 
 'use strict';
 
 /**
  * @param {Object.<string, string>} stringData String data.
  * @param {VolumeManager} volumeManager Volume manager.
  */
@@ skipping 95 matching lines @@
  * Promise to be fulfilled with entries that are used for reopening the
  * application window.
  * @type {Promise}
  */
 var reopenEntriesPromsie = null;
 
 /**
  * Launches the application with entries.
  *
  * @param {Promise} selectedEntriesPromise Promise to be fulfilled with the
- *     entries that are stored in the exteranl file system (not in the isolated
+ *     entries that are stored in the external file system (not in the isolated
  *     file system).
- * @return {Promise} Promise to be fulfilled after the applicaiton is launched.
+ * @return {Promise} Promise to be fulfilled after the application is launched.
  */
 function launch(selectedEntriesPromise) {
   // If there is the previous window, close the window.
   if (appWindowPromise) {
     reopenEntriesPromsie = selectedEntriesPromise;
     appWindowPromise.then(function(appWindow) {
       appWindow.close();
     });
     return Promise.reject('The window has already opened.');
   }
@@ skipping 77 matching lines @@
   chrome.runtime.onMessageExternal.addListener(function(message) {
     if (message.name !== 'testResourceLoaded')
       return;
     var script = document.createElement('script');
     script.src =
         'chrome-extension://ejhcmmdhhpdhhgmifplfmjobgegbibkn' +
         '/gallery/test_loader.js';
     document.documentElement.appendChild(script);
   });
 }