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

chrome/browser/resources/md_history/synced_device_manager.js

Index: chrome/browser/resources/md_history/synced_device_manager.js
diff --git a/chrome/browser/resources/md_history/synced_device_manager.js b/chrome/browser/resources/md_history/synced_device_manager.js
index 2a776551cb17ab22270d755a8f8581c6a89edaaa..433fb7f88a5487479147853bbbf669a99f3ef12d 100644
--- a/chrome/browser/resources/md_history/synced_device_manager.js
+++ b/chrome/browser/resources/md_history/synced_device_manager.js
@@ -57,6 +57,12 @@ Polymer({
     }
   },
 
+  /** @override */
+  attached: function() {
+    // Update the sign in state.
+    chrome.send('otherDevicesInitialized');
+  },
+
   /**
    * @param {!ForeignSession} session
    * @return {!ForeignDeviceInternal}