No longer start BG mode until a BackgroundContents is loaded

chrome/test/data/extensions/api_test/app_background_page/basic_close/test.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.
+
+// This test closes the existing background page opened by a.html.
+
+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 closeUrl =
+        pagePrefix.replace(/PORT/, config.testServer.port) + '/close.html';
+    chrome.tabs.create({ 'url': closeUrl }, function(tab) {});
+  });
+};
+
+// Background page is closed now.
+function onBackgroundPageClosed() {
+  chrome.test.notifyPass();
+};