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

Index: chrome/browser/resources/file_manager/js/file_manager_commands.js
diff --git a/chrome/browser/resources/file_manager/js/file_manager_commands.js b/chrome/browser/resources/file_manager/js/file_manager_commands.js
index a614b6248045ebceae1f406743b810ff00e9c385..b6d47cfa632d0cac606861355dfa1eb02e172362 100644
--- a/chrome/browser/resources/file_manager/js/file_manager_commands.js
+++ b/chrome/browser/resources/file_manager/js/file_manager_commands.js
@@ -257,8 +257,13 @@ Commands.newFolderCommand = {
  * 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);