Files.app: handle UNSUPPORTED_FILESYSTEM errors.

ui/file_manager/file_manager/background/js/volume_manager.js

 // Copyright (c) 2012 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';
 
 /**
  * Represents each volume, such as "drive", "download directory", each "USB
  * flush storage", or "mounted zip archive" etc.
  *
@@ skipping 561 matching lines @@
  * @private
  */
 VolumeManager.prototype.onMountCompleted_ = function(event) {
   this.mountQueue_.run(function(callback) {
     switch (event.eventType) {
       case 'mount':
         var requestKey = this.makeRequestKey_(
             'mount',
             event.volumeMetadata.sourcePath);
 
-        var error = event.status === 'success' ? '' : event.status;
-        if (!error || event.status === 'error_unknown_filesystem') {
+        if (event.status === 'success' ||
+            event.status ===
+                VolumeManagerCommon.VolumeError.UNKNOWN_FILESYSTEM ||
+            event.status ===
+                VolumeManagerCommon.VolumeError.UNSUPPORTED_FILESYSTEM) {
           volumeManagerUtil.createVolumeInfo(
               event.volumeMetadata,
               function(volumeInfo) {
                 this.volumeInfoList.add(volumeInfo);
                 this.finishRequest_(requestKey, event.status, volumeInfo);
 
                 if (volumeInfo.volumeType ===
                     VolumeManagerCommon.VolumeType.DRIVE) {
                   // Update the network connection status, because until the
                   // drive is initialized, the status is set to not ready.
@@ skipping 314 matching lines @@
       this.isDriveBased;
 
   /**
    * Whether the entry is read only or not.
    * @type {boolean}
    */
   this.isReadOnly = isReadOnly;
 
   Object.freeze(this);
 }