undo-xpopup seems to be unused

src/node/utils/tar.json

@@ -6,7 +6,6 @@
   , "pad.js"
   , "ace2_common.js"
   , "pad_utils.js"
-  , "undo-xpopup.js"
   , "json2.js"
   , "pad_cookie.js"
   , "pad_editor.js"
@@ -27,7 +26,6 @@
     "jquery.js"
   , "underscore.js"
   , "security.js"
-  , "undo-xpopup.js"
   , "json2.js"
   , "colorutils.js"
   , "draggable.js"

src/static/js/pad.js

@@ -30,7 +30,6 @@ require('./jquery');
 require('./farbtastic');
 require('./excanvas');
 JSON = require('./json2');
-require('./undo-xpopup');
 
 var chat = require('./chat').chat;
 var getCollabClient = require('./collab_client').getCollabClient;

src/static/js/timeslider.js

@@ -24,7 +24,6 @@
 // assigns to the global `$` and augments it with plugins.
 require('./jquery');
 JSON = require('./json2');
-require('./undo-xpopup');
 
 var createCookie = require('./pad_utils').createCookie;
 var readCookie = require('./pad_utils').readCookie;

src/static/js/undo-xpopup.js

@@ -1,34 +0,0 @@
-/**
- * This code is mostly from the old Etherpad. Please help us to comment this code. 
- * This helps other people to understand this code better and helps them to improve it.
- * TL;DR COMMENTS ON THIS FILE ARE HIGHLY APPRECIATED
- */
-
-/**
- * Copyright 2009 Google Inc.
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *      http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS-IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-if (window._orig_windowOpen)
-{
-  window.open = _orig_windowOpen;
-}
-if (window._orig_windowSetTimeout)
-{
-  window.setTimeout = _orig_windowSetTimeout;
-}
-if (window._orig_windowSetInterval)
-{
-  window.setInterval = _orig_windowSetInterval;
-}