MD Bookmarks: Add basic page features to new data-flow system

chrome/browser/resources/md_bookmarks/bookmarks_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.
 
 /**
  * @fileoverview A singleton datastore for the Bookmarks page. Page state is
  * publicly readable, but can only be modified by dispatching an Action to
  * the store.
  */
 
 cr.define('bookmarks', function() {
   /** @constructor */
   function Store() {
     /** @type {!BookmarksPageState} */
-    this.data_ = {};
+    this.data_ = bookmarks.util.createEmptyState();
     /** @type {boolean} */
     this.initialized_ = false;
     /** @type {!Array<!StoreObserver>} */
     this.observers_ = [];
   }
 
   Store.prototype = {
     /**
      * @param {!BookmarksPageState} initialState
      */
@@ skipping 47 matching lines @@
       });
     },
   };
 
   cr.addSingletonGetter(Store);
 
   return {
     Store: Store,
   };
 });