Implement a module system for the extension bindings JS.

chrome/renderer/resources/require.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 file should define a function that returns a require() method that can
-// be used to load JS modules.
-//
-// A module works the same as modules in node.js - JS script that populates
-// an exports object, which is what require()ers get returned. The JS in a
-// module will be run at most once as the exports result is cached.
-//
-// Modules have access to the require() function which can be used to load
-// other JS dependencies, and requireNative() which returns objects that
-// define native handlers.
-//
-// |bootstrap| contains the following fields:
-//   - GetSource(module): returns the source code for |module|
-//   - Run(source): runs the string os JS |source|
-//   - GetNative(nativeName): returns the named native object
-(function(bootstrap) {
-
-function wrap(source) {
-  return "(function(require, requireNative, exports) {" + source +
-      "\n})";
-}
-
-function ModuleLoader() {
-  this.cache_ = {};
-};
-
-ModuleLoader.prototype.run = function(id) {
-  var source = bootstrap.GetSource(id);
-  if (!source) {
-    return null;
-  }
-  var wrappedSource = wrap(source);
-  var f = bootstrap.Run(wrappedSource);
-  var exports = {};
-  f(require, requireNative, exports);
-  return exports;
-};
-
-ModuleLoader.prototype.load = function(id) {
-  var exports = this.cache_[id];
-  if (exports) {
-    return exports;
-  }
-  exports = this.run(id);
-  this.cache_[id] = exports;
-  return exports;
-};
-
-var moduleLoader = new ModuleLoader();
-
-function requireNative(nativeName) {
-  return bootstrap.GetNative(nativeName);
-}
-
-function require(moduleId) {
-  return moduleLoader.load(moduleId);
-}
-
-return require;
-});