Move a bunch of extension API tests to manifest_version 2.

chrome/test/data/extensions/api_test/app_background_page/basic/test.html

-<script>
-// This test runs through an expected use of a live background page:
-// - A live (web-extent) web page is loaded (a.html), which opens the background
-//   page.
-// - The first page is closed and a second live web page is loaded (b.html),
-//   which attempts to get still-running running background page. This second
-//   page also checks a counter which should have a value consistent with being
-//   called once from each of the first and second pages.
-// - The background page closes itself.
-
-var pageA;
-var pageB;
-var backgroundPageResponded = false;
-
-var pagePrefix =
-    'http://a.com:PORT/files/extensions/api_test/app_background_page/common';
-
-// Dispatch "tunneled" functions from the live web pages to this testing page.
-chrome.extension.onRequest.addListener(function(request) {
-  window[request.name](request.args);
-});
-
-// At no point should a window be created that contains the background page
-// (bg.html).
-chrome.tabs.onUpdated.addListener(function(tabId, changeInfo, tab) {
-  if (tab.url.match("bg\.html$")) {
-    chrome.test.notifyFail("popup opened instead of background page");
-  }
-});
-
-// Start the test by opening the first page in the app.
-window.onload = function() {
-  // We wait for window.onload before getting the test config.  If the
-  // config is requested before onload, then sometimes onload has already
-  // fired by the time chrome.test.getConfig()'s callback runs.
-  chrome.test.getConfig(function(config) {
-    var a_url =
-        pagePrefix.replace(/PORT/, config.testServer.port) + '/a.html';
-    chrome.tabs.create({ 'url': a_url }, function(tab) {
-      pageA = tab;
-    });
-  });
-}
-
-// Background page opened by pageA.
-function onBackgroundPageLoaded() {
-  chrome.tabs.remove(pageA.id, function() {
-    chrome.test.getConfig(function(config) {
-      var b_url =
-          pagePrefix.replace(/PORT/, config.testServer.port) + '/b.html';
-      chrome.tabs.create({ url: b_url }, function(tab) {
-        pageB = tab;
-      });
-    });
-  });
-}
-
-// Background page responded to pageB.
-function onBackgroundPageResponded() {
-  backgroundPageResponded = true;
-}
-
-// Background page is closing itself.
-function onBackgroundPageClosing() {
-  if (!backgroundPageResponded) {
-    chrome.test.notifyFail("background never responded to pageB");
-  } else {
-    chrome.test.notifyPass();
-  }
-}
-
-// The background counter check found an unexpected value (most likely caused
-// by an unwanted navigation.
-function onCounterError() {
-  chrome.test.notifyFail("checkCounter found an unexpected value");
-}
-
-</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="test.js"></script>