Fix auto opening FSP volumes on mount.

ui/file_manager/file_manager/foreground/js/directory_model.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.
 
 // If directory files changes too often, don't rescan directory more than once
 // per specified interval
 var SIMULTANEOUS_RESCAN_INTERVAL = 500;
 // Used for operations that require almost instant rescan.
 var SHORT_RESCAN_INTERVAL = 100;
 
@@ skipping 985 matching lines @@
       !this.volumeManager_.getVolumeInfo(this.getCurrentDirEntry())) {
     this.volumeManager_.getDefaultDisplayRoot(function(displayRoot) {
       this.changeDirectoryEntry(displayRoot);
     }.bind(this));
   }
 
   // If a new provided volume is mounted, then redirect to it in the focused
   // window. Note, that this is a temporary solution for crbug.com/427776.
   if (window.isFocused() &&
       event.added.length === 1 &&
-      event.added[0].volumeType ==
-          VolumeManagerCommon.VolumeType.VOLUME_TYPE_PROVIDED &&
-      event.added[0].displayRoot) {
-    this.changeDirectoryEntry(event.added[0].displayRoot);
+      event.added[0].volumeType === VolumeManagerCommon.VolumeType.PROVIDED) {
+    event.added[0].resolveDisplayRoot().then(function(displayRoot) {
+      // Resolving a display root on FSP volumes is instant, despite the
+      // asynchronous call.
+      this.changeDirectoryEntry(event.added[0].displayRoot);
+    }.bind(this));
   }
 };
 
 /**
  * Creates directory contents for the entry and query.
  *
  * @param {FileListContext} context File list context.
  * @param {DirectoryEntry} entry Current directory.
  * @param {string=} opt_query Search query string.
  * @return {DirectoryContents} Directory contents.
@@ skipping 115 matching lines @@
   if (this.onSearchCompleted_) {
     this.removeEventListener('scan-completed', this.onSearchCompleted_);
     this.onSearchCompleted_ = null;
   }
 
   if (this.onClearSearch_) {
     this.onClearSearch_();
     this.onClearSearch_ = null;
   }
 };