Video Player: Fix the private API error in Debug build

ui/file_manager/video_player/js/cast/media_manager.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';
 
 /**
  * Media manager class.
  * This class supports the information for the media file.
  * @param {FileEntry} entry Entry of media file. This must be a external entry.
@@ skipping 33 matching lines @@
  * @return {Promise} Promise which is resolved with the token. Reject if failed.
  */
 MediaManager.prototype.getToken = function(refresh) {
   if (this.cachedToken_ && !refresh)
     return Promise.resolve(this.cachedToken_);
 
   return new Promise(function(fulfill, reject) {
     // TODO(yoshiki): Creates the method to get a token and use it.
     chrome.fileBrowserPrivate.getDownloadUrl(this.entry_.toURL(), fulfill);
   }.bind(this)).then(function(url) {
+    if (chrome.runtime.lastError) {
+      return Promise.reject(
+          'Token fetch failed: ' + chrome.runtime.lastError.message);
+    }
     if (!url)
       return Promise.reject('Token fetch failed.');
     var token = url.substring(url.indexOf('access_token=') + 13);
     if (token) {
       this.cachedToken_ = token;
       return token;
     } else {
       return Promise.reject('Token fetch failed.');
     }
   }.bind(this));
 };
 
 /**
  * Retrives the url for cast.
  *
  * @return {Promise} Promise which is resolved with the url. Reject if failed.
  */
 MediaManager.prototype.getUrl = function() {
   if (this.cachedUrl_)
     return Promise.resolve(this.cachedUrl_);
 
   return new Promise(function(fulfill, reject) {
     // TODO(yoshiki): Creates the method to get a url and use it.
     chrome.fileBrowserPrivate.getDownloadUrl(this.entry_.toURL(), fulfill);
   }.bind(this)).then(function(url) {
+    if (chrome.runtime.lastError) {
+      return Promise.reject(
+          'URL fetch failed: ' + chrome.runtime.lastError.message);
+    }
     if (!url)
       return Promise.reject('URL fetch failed.');
     var access_token_index = url.indexOf('access_token=');
     if (access_token_index) {
       url = url.substring(0, access_token_index - 1);
     }
     this.cachedUrl_ = url;
     return url;
   }.bind(this));
 };
@@ skipping 36 matching lines @@
   }.bind(this)).then(function(props) {
     if (!props || !props[0] || !props[0].thumbnailUrl) {
       // TODO(yoshiki): Adds a logic to guess the mime.
       return Promise.reject('Thuumbnail fetch failed.');
     } else {
       this.cachedDriveProp_ = props[0];
       return props[0].thumbnailUrl;
     }
   }.bind(this));
 };