Upstream about:welcome page for Android.

chrome/browser/resources/about_welcome_android/about_welcome_android.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.
+
+// File Description:
+//     Contains all the necessary functions for rendering the Welcome page on
+//     Android.
+
+cr.define('about_welcome_android', function() {
+  'use strict';
+
+  /**
+   * Disable context menus.
+   */
+  function initialize() {
+    document.body.oncontextmenu = function(e) {
+      e.preventDefault();
+    }
+  }
+
+  // Return an object with all of the exports.
+  return {
+    initialize: initialize,
+  };
+});
+
+document.addEventListener('DOMContentLoaded', about_welcome_android.initialize);