MD History: Update sign in state in data source

chrome/browser/ui/webui/history_ui.h

Index: chrome/browser/ui/webui/history_ui.h
diff --git a/chrome/browser/ui/webui/history_ui.h b/chrome/browser/ui/webui/history_ui.h
index 13b012cde9ad1b887ad29a83066a495ad4377469..a4f74f55063329a8b31f5b284812580edb924f86 100644
--- a/chrome/browser/ui/webui/history_ui.h
+++ b/chrome/browser/ui/webui/history_ui.h
@@ -24,6 +24,11 @@ class HistoryUI : public content::WebUIController {
       ui::ScaleFactor scale_factor);
 
  private:
+  void CreateDataSource();
+
+  // Callback method to recreate data source when profile info changed.
+  void SignInChanged();
+
   DISALLOW_COPY_AND_ASSIGN(HistoryUI);
 };