MD Bookmarks: Scroll and select items that are added to the main list

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;
+      /** @type {?PromiseResolver} */
+      this.initPromise_ = null;
       this.enableReducers_ = false;
       /** @type {!Map<string, !PromiseResolver>} */
       this.resolverMap_ = new Map();
     };
 
     TestStore.prototype = {
       __proto__: bookmarks.Store.prototype,
 
       /** @override */
       init: function(state) {
-        if (this.acceptInit_)
+        if (this.initPromise_) {
           bookmarks.Store.prototype.init.call(this, state);
+          this.initPromise_.resolve();
+        }
       },
 
       get lastAction() {
         return this.lastAction_;
       },
 
       resetLastAction() {
         this.lastAction_ = null;
       },
 
@@ skipping 34 matching lines @@
       /**
        * Notifies UI elements that the store data has changed. When reducers are
        * disabled, tests are responsible for manually changing the data to make
        * UI elements update correctly (eg, tests must replace the whole list
        * when changing a single element).
        */
       notifyObservers: function() {
         this.notifyObservers_(this.data);
       },
 
-      // Call in order to accept data from an init call to the TestStore once.
+      /**
+       * Call in order to accept data from an init call to the TestStore once.
+       * @return {Promise} Promise which resolves when the store is initialized.
+       */
       acceptInitOnce: function() {
-        this.acceptInit_ = true;
+        this.initPromise_ = new PromiseResolver();
         this.initialized_ = false;
+        return this.initPromise_.promise;
       },
 
       /**
        * Track actions called |name|, allowing that type of action to be waited
        * for with `waitForAction`.
        * @param {string} name
        */
       expectAction: function(name) {
         this.resolverMap_.set(name, new PromiseResolver());
       },
@@ skipping 14 matching lines @@
           return action;
         });
       },
     };
 
     return {
       TestStore: TestStore,
     };
   });
 });