Defer syncing TopSites with history until the first tab closure

chrome/browser/win/jumplist.h

Index: chrome/browser/win/jumplist.h
diff --git a/chrome/browser/win/jumplist.h b/chrome/browser/win/jumplist.h
index c4b6c857584430198509a89a08b224963d7fb3e0..c5101d57048a440b9b0874e3b2ac18057bfbe758 100644
--- a/chrome/browser/win/jumplist.h
+++ b/chrome/browser/win/jumplist.h
@@ -233,6 +233,13 @@ class JumpList : public sessions::TabRestoreServiceObserver,
   // jumplist.
   base::OneShotTimer timer_recently_closed_;
 
+  // The number of tabs closed after Chrome launches.
+  int tab_closed_count_;
+
+  // A boolean flag indicating if the JumpList "most visited" category has been
+  // updated from the TopSites service.
+  bool initial_most_visited_update_done_;
+
   // Holds data that can be accessed from multiple threads.
   scoped_refptr<base::RefCountedData<JumpListData>> jumplist_data_;