Add the new window item to the Files.app's context menu on the launcher.

chrome/browser/resources/file_manager/js/file_manager_commands.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';
 
 var CommandUtil = {};
 
 /**
  * Extracts root on which command event was dispatched.
@@ skipping 239 matching lines @@
                        !fileManager.isRenamingInProgress() &&
                        !directoryModel.isSearching() &&
                        !directoryModel.isScanning();
   }
 };
 
 /**
  * Initiates new window creation.
  */
 Commands.newWindowCommand = {
-  execute: function(event, fileManager) {
-    chrome.fileBrowserPrivate.openNewWindow(document.location.href);
+  execute: function(event, fileManager, directoryModel) {
+    chrome.runtime.getBackgroundPage(function(background) {
+      var appState = {
+        defaultPath: directoryModel.getCurrentDirPath()
+      };
+      background.launchFileManager(appState);
+    });
   },
   canExecute: function(event, fileManager) {
     event.canExecute = (fileManager.dialogType == DialogType.FULL_PAGE);
   }
 };
 
 /**
  * Changed the default app handling inserted media.
  */
 Commands.changeDefaultAppCommand = {
@@ skipping 246 matching lines @@
 
 /**
  * Reset the zoom factor.
  */
 Commands.zoomResetCommand = {
   execute: function(event) {
     chrome.fileBrowserPrivate.zoom('reset');
   },
   canExecute: CommandUtil.canExecuteAlways
 };