Fix a possible race in WebViewTest.Shim_TestPartitionRaisesException.

chrome/test/data/extensions/platform_apps/web_view/shim/main.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.
 
 var util = {};
 var embedder = {};
 embedder.baseGuestURL = '';
 embedder.emptyGuestURL = '';
 embedder.windowOpenGuestURL = '';
 embedder.noReferrerGuestURL = '';
@@ skipping 562 matching lines @@
   webview.addEventListener('loadcommit', onLoadCommitA);
   webview.addEventListener('loadcommit', onLoadCommitB);
   webview.setAttribute('src', url);
 }
 
 // This test verifies that setting the partition attribute after the src has
 // been set raises an exception.
 function testPartitionRaisesException() {
   var webview = document.createElement('webview');
   webview.setAttribute('partition', arguments.callee.name);
-  webview.setAttribute('src', 'data:text/html,trigger navigation');
-  document.body.appendChild(webview);
-  setTimeout(function() {
+
+  var loadstopHandler = function(e) {
     try {
       webview.partition = 'illegal';
       embedder.test.fail();
     } catch (e) {
       embedder.test.succeed();
     }
-  }, 0);
+  };
+  webview.addEventListener('loadstop', loadstopHandler);
+
+  document.body.appendChild(webview);
+  webview.setAttribute('src', 'data:text/html,trigger navigation');
 }
 
 function testExecuteScriptFail() {
   var webview = document.createElement('webview');
   document.body.appendChild(webview);
   setTimeout(function() {
     try {
     webview.executeScript(
       {code:'document.body.style.backgroundColor = "red";'},
       function(results) {
@@ skipping 1129 matching lines @@
   'testFindAPI': testFindAPI,
   'testFindAPI_findupdate': testFindAPI
 };
 
 onload = function() {
   chrome.test.getConfig(function(config) {
     embedder.setUp_(config);
     chrome.test.sendMessage("Launched");
   });
 };