[MD History] Factor out a common HistoryListBehavior.

chrome/browser/resources/md_history/list_container.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-list-container',
 
   properties: {
     // The path of the currently selected page.
     selectedPage_: String,
@@ skipping 67 matching lines @@
 
     var maxResults =
       queryState.range == HistoryRange.ALL_TIME ? RESULTS_PER_PAGE : 0;
     chrome.send('queryHistory', [
       queryState.searchTerm, queryState.groupedOffset, queryState.range,
       lastVisitTime, maxResults
     ]);
   },
 
   unselectAllItems: function(count) {
-    /** @type {HistoryListElement} */ (this.$['infinite-list'])
-        .unselectAllItems(count);
+    this.getSelectedList_().unselectAllItems(count);
   },
 
   /**
    * Delete all the currently selected history items. Will prompt the user with
    * a dialog to confirm that the deletion should be performed.
    */
   deleteSelectedWithPrompt: function() {
     if (!loadTimeData.getBoolean('allowDeletingHistory'))
       return;
 
     this.$.dialog.showModal();
   },
 
   /**
    * @param {HistoryRange} range
    * @private
    */
   groupedRangeChanged_: function(range) {
     this.selectedPage_ = this.queryState.range == HistoryRange.ALL_TIME ?
       'infinite-list' : 'grouped-list';
 
     this.queryHistory(false);
   },
 
   /** @private */
   loadMoreHistory_: function() { this.queryHistory(true); },
 
-
   /**
    * @param {HistoryQuery} info
    * @param {!Array<HistoryEntry>} results
    * @private
    */
   initializeResults_: function(info, results) {
     if (results.length == 0)
       return;
 
     var currentDate = results[0].dateRelativeDay;
 
     for (var i = 0; i < results.length; i++) {
       // Sets the default values for these fields to prevent undefined types.
       results[i].selected = false;
       results[i].readableTimestamp =
           info.term == '' ? results[i].dateTimeOfDay : results[i].dateShort;
 
       if (results[i].dateRelativeDay != currentDate) {
         currentDate = results[i].dateRelativeDay;
       }
     }
   },
 
   /** @private */
   onDialogConfirmTap_: function() {
-    this.$['infinite-list'].deleteSelected();
+    this.$.content.selectedItem.deleteSelected();

[tsergeant, 2016/08/09 23:20:00]

Nit: Change this one as well.

[calamity, 2016/08/10 04:25:38]

Done.

     this.$.dialog.close();
   },
 
   /** @private */
   onDialogCancelTap_: function() {
     this.$.dialog.close();
   },
 
   /**
    * Closes the overflow menu.
@@ skipping 15 matching lines @@
         target, e.detail.item);
   },
 
   /** @private */
   onMoreFromSiteTap_: function() {
     var menu = /** @type {CrSharedMenuElement} */(this.$.sharedMenu);
     this.fire('search-domain', {domain: menu.itemData.domain});
     menu.closeMenu();
   },
 
+  /**
+   * @return {HTMLElement}
+   * @private
+   */
+  getSelectedList_: function() {

[tsergeant, 2016/08/09 23:20:00]

Ultra nit: Move this up or down so that it's not between the two menu item
handlers (since they're a pretty logical grouping).

[calamity, 2016/08/10 04:25:38]

Done.

+    return this.$.content.selectedItem;
+  },
+
   /** @private */
   onRemoveFromHistoryTap_: function() {
     var menu = /** @type {CrSharedMenuElement} */(this.$.sharedMenu);
     md_history.BrowserService.getInstance()
         .deleteItems([menu.itemData])
         .then(function(items) {
-          this.$['infinite-list'].removeDeletedHistory_(items);
+          this.$.content.selectedItem.removeItemsByPath(items[0].path);

[tsergeant, 2016/08/09 23:20:00]

Nit: And this one

[calamity, 2016/08/10 04:25:38]

Done.

           // This unselect-all is to reset the toolbar when deleting a selected
           // item. TODO(tsergeant): Make this automatic based on observing list
           // modifications.
           this.fire('unselect-all');
         }.bind(this));
     menu.closeMenu();
   },
 });