Delay updating jumplist to avoid blocking the file thread at start-up

chrome/browser/jumplist_win.h

Index: chrome/browser/jumplist_win.h
diff --git a/chrome/browser/jumplist_win.h b/chrome/browser/jumplist_win.h
index 8a801ba949797bd234617c0a9e23c373a411b310..1c2ca0ed90fba9a8f62cdc0db3af8b1fc1f4eced 100644
--- a/chrome/browser/jumplist_win.h
+++ b/chrome/browser/jumplist_win.h
@@ -204,6 +204,12 @@ class JumpList : public TabRestoreServiceObserver,
   friend struct content::BrowserThread::DeleteOnThread<
       content::BrowserThread::UI>;
   friend class base::DeleteHelper<JumpList>;
+  enum UpdateStatus {
+   UPDATE_NOT_RUN = 0,
+   UPDATE_PENDING = 1,
+   NONE_PENDING = 2
+  };
+
   ~JumpList();
 
   // For callbacks may be run after destruction.
@@ -244,6 +250,8 @@ class JumpList : public TabRestoreServiceObserver,
   // Lock for most_visited_pages_, recently_closed_pages_, icon_urls_
   // as they may be used by up to 3 threads.
   base::Lock list_lock_;
+
+  UpdateStatus status_;
 };
 
 #endif  // CHROME_BROWSER_JUMPLIST_WIN_H_