[MD Bookmarks] Refactor window timer mocking.

chrome/test/data/webui/md_bookmarks/test_store.js

 // Copyright 2017 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.
 
 suiteSetup(function() {
   cr.define('bookmarks', function() {
     var TestStore = function(data) {
       bookmarks.Store.call(this);
       this.data_ = Object.assign(bookmarks.util.createEmptyState(), data);
       this.initialized_ = true;
 
       this.lastAction_ = null;
       this.acceptInit_ = false;
       this.enableReducers_ = false;
       /** @type {!Map<string, !PromiseResolver>} */
       this.resolverMap_ = new Map();
     };
 
     TestStore.prototype = {
       __proto__: bookmarks.Store.prototype,
 
+      /** @override */
       init: function(state) {
         if (this.acceptInit_)
           bookmarks.Store.prototype.init.call(this, state);
       },
 
       get lastAction() {
         return this.lastAction_;
       },
 
       resetLastAction() {
@@ skipping 18 matching lines @@
        * With reducers disabled (the default), TestStore is a stub which
        * requires state be managed manually (suitable for unit tests). With
        * reducers enabled, TestStore becomes a proxy for observing actions
        * (suitable for integration tests).
        * @param {boolean} enabled
        */
       setReducersEnabled: function(enabled) {
         this.enableReducers_ = enabled;
       },
 
+      /** @override */
       reduce_: function(action) {
         this.lastAction_ = action;
         if (this.enableReducers_)
           bookmarks.Store.prototype.reduce_.call(this, action);
         if (this.resolverMap_.has(action.name))
           this.resolverMap_.get(action.name).resolve(action);
       },
 
       /**
        * Notifies UI elements that the store data has changed. When reducers are
@@ skipping 36 matching lines @@
           return action;
         });
       },
     };
 
     return {
       TestStore: TestStore,
     };
   });
 });