Add 'New window' option to context menu.

remoting/webapp/background.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.
 
-chrome.app.runtime.onLaunched.addListener(function() {
+/** @type {string} */
+var kNewWindowId = 'new-window';
+
+function createWindow() {
   chrome.app.window.create('main.html', {
     'width': 800,
     'height': 600
   });
-});
+};
+
+/** @param {OnClickData} info */
+function onContextMenu(info) {
+  if (info.menuItemId == kNewWindowId) {
+    createWindow();
+  }
+};
+
+function initializeContextMenu() {
+  chrome.contextMenus.create({
+     id: kNewWindowId,
+     contexts: ['launcher'],
+     title: chrome.i18n.getMessage(/*i18n-content*/'NEW_WINDOW')
+  });
+}
+
+chrome.app.runtime.onLaunched.addListener(createWindow);
+chrome.contextMenus.onClicked.addListener(onContextMenu);
+initializeContextMenu();