[ios Mojo] Supporting code for define WebUI function.

ios/web/webui/resources/web_ui_module_load_notifier.js

+// Copyright 2016 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.
+
+goog.provide('__crWeb.webUIModuleLoadNotifier');
+
+/**
+ * A holder class for require.js contexts whose load is pending.
+ * @constructor
+ */
+var WebUIModuleLoadNotifier = function() {
+  this.lastUsedId_ = 0;
+  this.pendingContexts_ = {};
+};
+
+/**
+ * Adds the given context to the list of pending contexts.
+ * @param {string} name Name of the module that will be loaded.
+ * @param {Object} context Require.js context to hold.
+ * @return {String} Identifier for the added context, can be later used for

[dpapad, 2016/04/28 22:29:20]

s/String/string/

[Eugene But (OOO till 7-30), 2016/04/29 00:10:41]

Done.

+ *     {@code moduleLoadCompleted} and {@code moduleLoadFailed} arguments.
+ */
+WebUIModuleLoadNotifier.prototype.addPendingContext = function(name, context) {
+  var loadId = this.lastUsedId_ + 1;
+  this.lastUsedId_ = loadId;

[dpapad, 2016/04/28 22:29:20]

I am confused by lines 24-25, it seems that loadId local var is not needed at
all.

this.lastUsedId_++;
var key = name + this.lastUsedId_;
...

[dpapad, 2016/04/28 22:29:20]

I am confused by lines 24-25, it seems that loadId local var is not needed at
all.

this.lastUsedId_++;
var key = name + this.lastUsedId_;
...

[Eugene But (OOO till 7-30), 2016/04/29 00:10:41]

Done.

+  var key = name + loadId;
+  this.pendingContexts_[key] = context;
+  return String(loadId);
+}

[dpapad, 2016/04/28 22:29:20]

Nit: Semicolon missing, here and elsewhere.

+
+/**
+ * Signals that module has successfully loaded.
+ * @param {string} name Name of the module that has been loaded.
+ * @param {String} loadId Identifier returned from {@code addPendingContext}.
+ */
+WebUIModuleLoadNotifier.prototype.moduleLoadCompleted = function(name, loadId) {
+  this.popContext_(name, loadId).completeLoad(name);
+}
+
+/**
+ * Signals that module has failed to load.
+ * @param {string} name Name of the module that has failed to load.
+ * @param {String} loadId Identifier returned from {@code addPendingContext}.
+ */
+WebUIModuleLoadNotifier.prototype.moduleLoadFailed = function(name, loadId) {
+  this.popContext_(name, loadId).onScriptFailure(name);
+}
+
+WebUIModuleLoadNotifier.prototype.popContext_ = function(name, loadId) {
+  var key = name + loadId;
+  var context = this.pendingContexts_[key];
+  delete this.pendingContexts_[key];
+  return context;
+}