MD History: Get sign in state from backend when refreshing the page

chrome/browser/resources/md_history/synced_device_manager.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.
 
 /**
  * @typedef {{device: string,
  *           lastUpdateTime: string,
  *           separatorIndexes: !Array<number>,
  *           timestamp: number,
  *           tabs: !Array<!ForeignSessionTab>,
@@ skipping 39 matching lines @@
       value: loadTimeData.getBoolean('isGuestSession'),
     },
 
     /** @private */
     fetchingSyncedTabs_: {
       type: Boolean,
       value: false,
     }
   },
 
+  /** @override */
+  attached: function() {
+    // Update the sign in state.
+    chrome.send('otherDevicesInitialized');
+  },
+
   /**
    * @param {!ForeignSession} session
    * @return {!ForeignDeviceInternal}
    */
   createInternalDevice_: function(session) {
     var tabs = [];
     var separatorIndexes = [];
     for (var i = 0; i < session.windows.length; i++) {
       var windowId = session.windows[i].sessionId;
       var newTabs = session.windows[i].tabs;
@@ skipping 134 matching lines @@
     // User signed in, show the loading message when querying for synced
     // devices.
     this.fetchingSyncedTabs_ = true;
   },
 
   searchTermChanged: function(searchTerm) {
     this.clearDisplayedSyncedDevices_();
     this.updateSyncedDevices(this.sessionList);
   }
 });