Video Player: fix misc bugs

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 84 matching lines @@
   }.bind(this));
 };
 
 /**
  * Retrieves the mime of file.
  *
  * @return {Promise} Promise which is resolved with the mime. Reject if failed.
  */
 MediaManager.prototype.getMime = function() {
   if (this.cachedDriveProp_)
-    return Promise.resolve(this.cachedDriveProp_.thumbnailUrl);
+    return Promise.resolve(this.cachedDriveProp_.contentMimeType || '');
 
   return new Promise(function(fulfill, reject) {
     chrome.fileBrowserPrivate.getEntryProperties(
         [this.entry_.toURL()], fulfill);
   }.bind(this)).then(function(props) {
-    if (!props || !props[0] || !props[0].contentMimeType) {
+    if (!props || !props[0]) {
+      return Promise.reject('Mime fetch failed.');
+    } else if (!props[0].contentMimeType) {
       // TODO(yoshiki): Adds a logic to guess the mime.
-      return Promise.reject('Mime fetch failed.');
+      this.cachedDriveProp_ = props[0];
+      return '';
     } else {
       this.cachedDriveProp_ = props[0];
       return props[0].contentMimeType;
     }
   }.bind(this));
 };
 
 /**
  * Retrieves the thumbnail url of file.
  *
  * @return {Promise} Promise which is resolved with the url. Reject if failed.
  */
 MediaManager.prototype.getThumbnail = function() {
   if (this.cachedDriveProp_)
-    return Promise.resolve(this.cachedDriveProp_.thumbnailUrl);
+    return Promise.resolve(this.cachedDriveProp_.thumbnailUrl || '');
 
   return new Promise(function(fulfill, reject) {
     chrome.fileBrowserPrivate.getEntryProperties(
         [this.entry_.toURL()], fulfill);
   }.bind(this)).then(function(props) {
-    if (!props || !props[0] || !props[0].thumbnailUrl) {
-      // TODO(yoshiki): Adds a logic to guess the mime.
+    if (!props || !props[0]) {
       return Promise.reject('Thumbnail fetch failed.');
     } else {
       this.cachedDriveProp_ = props[0];
-      return props[0].thumbnailUrl;
+      return props[0].thumbnailUrl || '';
     }
   }.bind(this));
 };