diff -r 000000000000 -r 6474c204b198 toolkit/modules/LoadContextInfo.jsm
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/toolkit/modules/LoadContextInfo.jsm	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,62 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+this.EXPORTED_SYMBOLS = ["LoadContextInfo"];
+
+const Ci = Components.interfaces;
+const Cc = Components.classes;
+const Cr = Components.results;
+
+Components.utils.import("resource://gre/modules/XPCOMUtils.jsm");
+
+this.LoadContextInfo = {};
+
+_LoadContextInfo.prototype = {
+  QueryInterface: XPCOMUtils.generateQI([Ci.nsILoadContextInfo, Ci.nsISupports]),
+  get isPrivate() { return this._isPrivate },
+  get isAnonymous() { return this._isAnonymous },
+  get isInBrowserElement() { return this._isInBrowserElement },
+  get appId() { return this._appId }
+}
+
+function _LoadContextInfo(_private, _anonymous, _appId, _inBrowser) {
+  this._isPrivate = _private || false;
+  this._isAnonymous = _anonymous || false;
+  this._appId = _appId || 0;
+  this._isInBrowserElement = _inBrowser || false;
+}
+
+// LoadContextInfo.default
+
+// Non-private, non-anonymous, no app ID, not in browser
+XPCOMUtils.defineLazyGetter(LoadContextInfo, "default", function () {
+  return new _LoadContextInfo(false, false, 0, false);
+});
+
+// LoadContextInfo.private
+
+// Private, non-anonymous, no app ID, not in browser
+XPCOMUtils.defineLazyGetter(LoadContextInfo, "private", function () {
+  return new _LoadContextInfo(true, false, 0, false);
+});
+
+// LoadContextInfo.anonymous
+
+// Non-private, anonymous, no app ID, not in browser
+XPCOMUtils.defineLazyGetter(LoadContextInfo, "anonymous", function () {
+  return new _LoadContextInfo(false, true, 0, false);
+});
+
+// Fully customizable
+LoadContextInfo.custom = function(_private, _anonymous, _appId, _inBrowser) {
+  return new _LoadContextInfo(_private, _anonymous, _appId, _inBrowser);
+}
+
+// Copies info from provided nsILoadContext
+LoadContextInfo.fromLoadContext = function(_loadContext, _anonymous) {
+  return new _LoadContextInfo(_loadContext.isPrivate,
+                              _anonymous,
+                              _loadContext.appId,
+                              _loadContext.isInBrowserElement);
+}