[Extensions] Propagate activeTab hosts to extension background pages

chrome/test/data/extensions/api_test/active_tab/background.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 assertEq = chrome.test.assertEq;
 var assertFalse = chrome.test.assertFalse;
 var assertTrue = chrome.test.assertTrue;
 var callbackFail = chrome.test.callbackFail;
 var callbackPass = chrome.test.callbackPass;
 
 var RoleType = chrome.automation.RoleType;
 
+var url = null;
+
+function canXhr() {
+  assertFalse(url == null);
+  var xhr = new XMLHttpRequest();
+  xhr.open('GET', url, false);
+  var success = true;
+  try {
+    xhr.send();
+  } catch(e) {
+    success = false;
+  }
+  return success;
+}
+
 chrome.browserAction.onClicked.addListener(function() {
   chrome.tabs.executeScript({ code: 'true' }, callbackPass());
+
+  assertTrue(canXhr(url));

[not at google - send to devlin, 2015/02/03 19:29:12]

canXhr() doesn't take a URL, but it seems like this call does have the right
idea, and it *should* take a URL.

[Devlin, 2015/02/04 22:26:02]

It was my circumvention around doing an async tabs.query call.  But done.

+
   chrome.automation.getTree(callbackPass(function(rootNode) {
     assertFalse(rootNode == undefined);
     assertEq(RoleType.rootWebArea, rootNode.role);
     chrome.test.succeed();
   }));
 });
 
 chrome.webNavigation.onCompleted.addListener(function(details) {
   chrome.tabs.executeScript({ code: 'true' }, callbackFail(
          'Cannot access contents of url "' + details.url +
          '". Extension manifest must request permission to access this host.'));
 
   chrome.automation.getTree(callbackFail(
       'Cannot request automation tree on url "' + details.url +
         '". Extension manifest must request permission to access this host.'));
+
+  url = details.url;
+  assertFalse(canXhr());
 });