MD History: Add icon in top right of page when showing synced results

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',
 
   behaviors: [Polymer.IronScrollTargetBehavior],
 
   properties: {
+    // Used to display notices for profile sign-in status.
     showSidebarFooter: Boolean,
 
+    hasSyncedResults: Boolean,
+
     // The id of the currently selected page.
     selectedPage_: {type: String, observer: 'unselectAll'},
 
     // Whether domain-grouped history is enabled.
     grouped_: {type: Boolean, reflectToAttribute: true},
 
     /** @type {!QueryState} */
     queryState_: {
       type: Object,
       value: function() {
@@ skipping 263 matching lines @@
    * @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 != '';
   },
 
   /**
+   * @param {boolean} hasSyncedResults
+   * @param {string} selectedPage
+   * @return {boolean} Whether the (i) synced results notice should be shown.
+   * @private
+   */
+  showSyncNotice_: function(hasSyncedResults, selectedPage) {
+    return hasSyncedResults && selectedPage != 'syncedTabs';
+  },
+
+  /**
    * @param {string} page
    * @private
    */
   routeDataChanged_: function(page) { this.selectedPage_ = page; },
 
   /**
    * @param {string} selectedPage
    * @private
    */
   selectedPageChanged_: function(selectedPage) {
@@ skipping 53 matching lines @@
             break;
         }
         break;
     }
 
     md_history.BrowserService.getInstance().recordHistogram(
       'History.HistoryPageView', histogramValue, HistoryPageViewHistogram.END
     );
   },
 });