Show dictionary changes in chrome://settings/editDictionary as changes come in

chrome/browser/ui/webui/options/edit_dictionary_browsertest.js

 // Copyright (c) 2012 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.
 
 /**
  * TestFixture for EditDictionaryOverlay WebUI testing.
  * @extends {testing.Test}
  * @constructor
  **/
 function EditDictionaryWebUITest() {}
@@ skipping 17 matching lines @@
         ]);
     this.mockHandler.stubs().refreshDictionaryWords().
         will(callFunction(function() {
           EditDictionaryOverlay.setWordList([]);
         }));
     this.mockHandler.stubs().addDictionaryWord(ANYTHING);
     this.mockHandler.stubs().removeDictionaryWord(ANYTHING);
   },
 };
 
+// Verify that users can add and remove words in the dictionary.
 TEST_F('EditDictionaryWebUITest', 'testAddRemoveWords', function() {
   var testWord = 'foo';
   $('language-dictionary-overlay-word-list').querySelector('input').value =
       testWord;
 
   this.mockHandler.expects(once()).addDictionaryWord([testWord]).
       will(callFunction(function() {
           EditDictionaryOverlay.setWordList([testWord]);
       }));
   var addWordItem = EditDictionaryOverlay.getWordListForTesting().items[0];
   addWordItem.onEditCommitted_({currentTarget: addWordItem});
 
   this.mockHandler.expects(once()).removeDictionaryWord([testWord]).
       will(callFunction(function() {
           EditDictionaryOverlay.setWordList([]);
       }));
   EditDictionaryOverlay.getWordListForTesting().deleteItemAtIndex(0);
 });
 
+// Verify that users can search words in the dictionary.
 TEST_F('EditDictionaryWebUITest', 'testSearch', function() {
   EditDictionaryOverlay.setWordList(['foo', 'bar']);
   expectEquals(3, EditDictionaryOverlay.getWordListForTesting().items.length);
 
   /**
    * @param {Element} el The element to dispatch an event on.
    * @param {string} value The text of the search event.
    */
   var fakeSearchEvent = function(el, value) {
     el.value = value;
     cr.dispatchSimpleEvent(el, 'search');
   };
   var searchField = $('language-dictionary-overlay-search-field');
   fakeSearchEvent(searchField, 'foo');
   expectEquals(2, EditDictionaryOverlay.getWordListForTesting().items.length);
 
   fakeSearchEvent(searchField, '');
   expectEquals(3, EditDictionaryOverlay.getWordListForTesting().items.length);
 });
+
+// Verify that dictionary shows newly added words that arrived in a
+// notification, but ignores duplicate add notifications.
+TEST_F('EditDictionaryWebUITest', 'testAddNotification', function() {
+  // Begin with an empty dictionary.
+  EditDictionaryOverlay.setWordList([]);
+  expectEquals(1, EditDictionaryOverlay.getWordListForTesting().items.length);
+
+  // User adds word 'foo'.
+  EditDictionaryOverlay.getWordListForTesting().addDictionaryWord_('foo');
+  expectEquals(2, EditDictionaryOverlay.getWordListForTesting().items.length);
+
+  // Backend notifies UI that the word 'foo' has been added. UI ignores this
+  // notification, because the word is displayed immediately after user added
+  // it.
+  EditDictionaryOverlay.updateWords(['foo'], []);
+  expectEquals(2, EditDictionaryOverlay.getWordListForTesting().items.length);
+
+  // Backend notifies UI that the words 'bar' and 'baz' were added. UI shows
+  // these new words.
+  EditDictionaryOverlay.updateWords(['bar', 'baz'], []);
+  expectEquals(4, EditDictionaryOverlay.getWordListForTesting().items.length);
+});
+
+// Verify that dictionary hides newly removed words that arrived in a
+// notification, but ignores duplicate remove notifications.
+TEST_F('EditDictionaryWebUITest', 'testRemoveNotification', function() {
+  // Begin with a dictionary with words 'foo', 'bar', 'baz', and 'baz'. The
+  // second instance of 'baz' appears because the user added the word twice.
+  // The backend keeps only one copy of the word.
+  EditDictionaryOverlay.setWordList(['foo', 'bar', 'baz', 'baz']);
+  expectEquals(5, EditDictionaryOverlay.getWordListForTesting().items.length);
+
+  // User deletes the second instance of 'baz'.
+  EditDictionaryOverlay.getWordListForTesting().deleteItemAtIndex(3);
+  expectEquals(4, EditDictionaryOverlay.getWordListForTesting().items.length);
+
+  // Backend notifies UI that the word 'baz' has been removed. UI ignores this
+  // notification.
+  EditDictionaryOverlay.updateWords([], ['baz']);
+  expectEquals(4, EditDictionaryOverlay.getWordListForTesting().items.length);
+
+  // Backend notifies UI that words 'foo' and 'bar' have been removed. UI
+  // removes these words.
+  EditDictionaryOverlay.updateWords([], ['foo', 'bar']);
+  expectEquals(2, EditDictionaryOverlay.getWordListForTesting().items.length);
+});