Move allocate instance id to chrome/.

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 561 matching lines @@
   // on the <webview> tag.
   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);
+  var partitionAttribute = arguments.callee.name;
+  webview.setAttribute('partition', partitionAttribute);
   webview.setAttribute('src', 'data:text/html,trigger navigation');
   document.body.appendChild(webview);
   setTimeout(function() {
     try {
       webview.partition = 'illegal';
       embedder.test.fail();
     } catch (e) {
+      embedder.test.assertEq(partitionAttribute, webview.partition);
       embedder.test.succeed();
     }
   }, 0);
 }
 
 function testExecuteScriptFail() {
   var webview = document.createElement('webview');
   document.body.appendChild(webview);
   setTimeout(function() {
     try {
@@ skipping 1106 matching lines @@
   'testFindAPI': testFindAPI,
   'testFindAPI_findupdate': testFindAPI
 };
 
 onload = function() {
   chrome.test.getConfig(function(config) {
     embedder.setUp_(config);
     chrome.test.sendMessage("Launched");
   });
 };