Flip --enable-apps-show-on-first-paint flag.

chrome/test/data/extensions/platform_apps/pointer_lock/has_permission/window.js

 // Copyright 2013 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.
 
-window.onload = function () {
+chrome.app.window.current().onWindowFirstShown.addListener(function() {
+  console.log('poo');
   chrome.test.sendMessage('Launched', function() {
     chrome.test.runTests([
       function requestPointerLock() {
         document.onwebkitpointerlockchange = chrome.test.succeed;
         document.onwebkitpointerlockerror = chrome.test.fail;
         document.body.webkitRequestPointerLock();
       },
     ]);
   });
-}
+});