filemanager: Files App change necessary to use "drive/root". It still works with "drive".

chrome/browser/resources/file_manager/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 = 1000;
 // Used for operations that require almost instant rescan.
 var SHORT_RESCAN_INTERVAL = 100;
 
@@ skipping 39 matching lines @@
    * @type {Object.<string, string>}
    * @private
    */
   this.currentDirByRoot_ = {};
 
   this.volumeManager_ = volumeManager;
 }
 
 /**
  * Fake entry to be used in currentDirEntry_ when current directory is
- * unmounted DRIVE.
+ * unmounted DRIVE. TODO(haruki): Support "drive/root" and "drive/other".
  * @private
  */
 DirectoryModel.fakeDriveEntry_ = {
   fullPath: RootDirectory.DRIVE,
   isDirectory: true
 };
 
 /**
  * Fake entry representing a psuedo directory, which contains Drive files
  * available offline. This entry works as a trigger to start a search using
@@ skipping 1017 matching lines @@
 
   readSingle(RootDirectory.DOWNLOADS.substring(1), 'downloads');
   util.readDirectory(root, RootDirectory.ARCHIVE.substring(1),
                      append.bind(this, 'archives'));
   util.readDirectory(root, RootDirectory.REMOVABLE.substring(1),
                      append.bind(this, 'removables'));
 
   if (this.driveEnabled_) {
     var fake = [DirectoryModel.fakeDriveEntry_];
     if (this.isDriveMounted()) {
-      readSingle(RootDirectory.DRIVE.substring(1), 'drive', fake);
+      readSingle(DirectoryModel.fakeDriveEntry_.fullPath, 'drive', fake);
     } else {
       groups.drive = fake;
     }
     // TODO(haruki): Add DirectoryModel.fakeDriveOfflineEntry_ to show the tab.
   } else {
     groups.drive = [];
   }
 };
 
 /**
@@ skipping 68 matching lines @@
     var onGotDirectory = function(entry) {
       this.updateRootEntry_(entry);
       var currentDirEntry = this.getCurrentDirEntry();
       if (currentDirEntry == DirectoryModel.fakeDriveEntry_) {
         this.changeDirectoryEntrySilent_(entry);
       } else if (currentDirEntry == DirectoryModel.fakeDriveOfflineEntry_) {
         // Need to update the results for offline available files.
         this.getDriveOfflineFiles('');
       }
     }
-    this.root_.getDirectory(RootDirectory.DRIVE, {},
-                            onGotDirectory.bind(this));
+    this.root_.getDirectory(
+        DirectoryModel.fakeDriveEntry_.fullPath, {},
+        onGotDirectory.bind(this));
+    // TODO(haruki): support "other" root.
   } else {
     var rootType = this.getCurrentRootType();
     if (rootType != RootType.DRIVE && rootType != RootType.DRIVE_OFFLINE)
       return;
 
     // Current entry unmounted. Replace with fake drive one.
     this.updateRootEntry_(DirectoryModel.fakeDriveEntry_);
     if (this.getCurrentDirPath() == DirectoryModel.fakeDriveEntry_.fullPath) {
       // Replace silently and rescan.
       this.changeDirectoryEntrySilent_(DirectoryModel.fakeDriveEntry_);
@@ skipping 305 matching lines @@
         }.bind(this));
   }
 };
 
 /**
  * @return {DirectoryEntry} Current watched directory entry.
  */
 FileWatcher.prototype.getWatchedDirectoryEntry = function() {
   return this.watchedDirectoryEntry_;
 };