MD Bookmarks: Integrate new data store with UI elements

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.
+
+cr.define('bookmarks', function() {
+  var TestStore = function(data) {
+    this.data = Object.assign(bookmarks.util.createEmptyState(), data);
+    this.lastAction_ = null;
+    this.observers_ = [];
+  };
+
+  TestStore.prototype = {
+    addObserver: function(client) {
+      this.observers_.push(client);
+    },
+
+    removeObserver: function(client) {},
+
+    isInitialized: function() {
+      return true;
+    },
+
+    handleAction: function(action) {
+      this.lastAction_ = action;
+    },
+
+    get lastAction() {
+      return this.lastAction_;
+    },
+
+    notifyObservers: function() {
+      // TODO(tsergeant): Revisit how state modifications work in UI tests.
+      // We don't want tests to worry about modifying the whole state tree.
+      // Instead, we could perform a deep clone in here to ensure that every
+      // StoreClient is updated.
+      this.observers_.forEach((client) => client.onStateChanged(this.data));
+    },
+  };
+
+  return {
+    TestStore: TestStore,
+  };
+});