The Tor Browser / file revision

 /* 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/. */

 "use strict";

 module.metadata = {

   "stability": "unstable",

   "engines": {

     "Firefox": "*",

     "Fennec": "*"

   }

 };

 const { modelFor } = require("./model/core");

 const { viewFor } = require("./view/core");

 const { isTab } = require("./tabs/utils");

 if (require("./system/xul-app").is("Fennec")) {

   module.exports = require("./windows/tabs-fennec").tabs;

 }

 else {

   module.exports = require("./tabs/tabs-firefox");

 }

 const tabs = module.exports;

 // Implement `modelFor` function for the Tab instances.

 // Finds a right model by iterating over all tab models

 // and finding one that wraps given `view`.

 modelFor.when(isTab, view => {

   for (let model of tabs) {

     if (viewFor(model) === view)

       return model;

   }

   return null;

 });