Move another block of extension tests to manifest_version 2.

chrome/test/data/extensions/api_test/infobars/infobarA.html

Index: chrome/test/data/extensions/api_test/infobars/infobarA.html
===================================================================
--- chrome/test/data/extensions/api_test/infobars/infobarA.html	(revision 112170)
+++ chrome/test/data/extensions/api_test/infobars/infobarA.html	(working copy)
@@ -1,10 +1,8 @@
-<script>
-  const assertEq = chrome.test.assertEq;
-  var background_page = chrome.extension.getBackgroundPage();
-  chrome.tabs.getCurrent(function(tab) {
-    assertEq(background_page.tabA, tab.id);
-    background_page.infobarCallbackA();
-  });
-</script>
+<!--
+ * Copyright (c) 2011 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.
+-->
+<script src="inforbarA.js"></script>
 
-Infobar A
+Infobar A