MD History: Add confirmation dialog when deleting items from the toolbar

chrome/browser/resources/md_history/app.js

 // Copyright 2016 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.
 
 Polymer({
   is: 'history-app',
 
   properties: {
     // The id of the currently selected page.
     selectedPage_: {type: String, value: 'history', observer: 'unselectAll'},
@@ skipping 67 matching lines @@
    * @private
    */
   unselectAll: function() {
     var listContainer =
         /** @type {HistoryListContainerElement} */ (this.$['history']);
     var toolbar = /** @type {HistoryToolbarElement} */ (this.$.toolbar);
     listContainer.unselectAllItems(toolbar.count);
     toolbar.count = 0;
   },
 
-  /**
-   * Listens for call to delete all selected items and loops through all items
-   * to determine which ones are selected and deletes these.
-   */
   deleteSelected: function() {
-    if (!loadTimeData.getBoolean('allowDeletingHistory'))
-      return;
-
-    // TODO(hsampson): add a popup to check whether the user definitely
-    // wants to delete the selected items.
-    /** @type {HistoryListContainerElement} */ (this.$['history'])
-        .deleteSelected();
+    this.$.history.deleteSelectedWithPrompt();
   },
 
   /**
    * @param {HistoryQuery} info An object containing information about the
    *    query.
    * @param {!Array<HistoryEntry>} results A list of results.
    */
   historyResult: function(info, results) {
     this.set('queryState_.querying', false);
     this.set('queryResult_.info', info);
@@ skipping 46 matching lines @@
    * @param {boolean} incremental
    * @param {string} searchTerm
    * @return {boolean} Whether a loading spinner should be shown (implies the
    *     backend is querying a new search term).
    * @private
    */
   shouldShowSpinner_: function(querying, incremental, searchTerm) {
     return querying && !incremental && searchTerm != '';
   },
 });