Hide requests in an extension from other extensions

chrome/test/data/extensions/api_test/webrequest_extensions/extension/contentscript.js

+// Copyright 2015 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.
+
+// location.origin will be equivalent to 'http://example.com:PORT';
+var baseUrl = location.origin;
+
+chrome.test.sendMessage('contentscript_ready', function() {
+  var x = new XMLHttpRequest();
+  x.open('GET', baseUrl + '/extensions/test_file.txt?contentscript');
+  x.onloadend = function() {
+    chrome.test.assertEq('Hello!', x.responseText);
+
+    chrome.test.sendMessage('contentscript_done', function() {
+      var frame = document.createElement('iframe');
+      frame.src = chrome.runtime.getURL('frame.html');
+      document.body.appendChild(frame);
+    });
+  };
+  x.send();
+});