Move another bunch of extension API tests to manifest_version 2.

chrome/test/data/extensions/api_test/content_scripts/extension_process/background.html

 <!--
-Copyright (c) 2009 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.
+ * 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.
 -->
-
 <!--
 Two common ways that we can end up with web pages running in an extension
 process are iframes and popup windows.
 -->
-<script>
-var numPings = 0;
-chrome.extension.onRequest.addListener(function(data) {
-  if (data != "ping")
-    chrome.test.fail("Unexpected request: " + JSON.stringify(data));
-
-  if (++numPings == 2)
-    chrome.test.notifyPass();
-});
-
-chrome.test.getConfig(function(config) {
-  var test_file_url = "http://localhost:PORT/files/extensions/test_file.html"
-      .replace(/PORT/, config.testServer.port);
-
-  // Add a window.
-  var w = window.open(test_file_url);
-
-  // Add an iframe.
-  var iframe = document.createElement("iframe");
-  iframe.src = test_file_url;
-  document.getElementById("iframeContainer").appendChild(iframe);
-});
-
-</script>
-
+<script src="background.js"></script>
 <div id="iframeContainer"> </div>