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

chrome/browser/jumplist_win.h

 // Copyright (c) 2012 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.
 
 #ifndef CHROME_BROWSER_JUMPLIST_WIN_H_
 #define CHROME_BROWSER_JUMPLIST_WIN_H_
 
 #include <list>
 #include <string>
 #include <utility>
@@ skipping 186 matching lines @@
   void RunUpdate();
 
   // Helper method for RunUpdate to create icon files for the asynchrounously
   // loaded icons.
   void CreateIconFiles(const ShellLinkItemList& item_list);
 
  private:
   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.
   base::WeakPtrFactory<JumpList> weak_ptr_factory_;
 
   // Tracks FaviconService tasks.
   CancelableTaskTracker cancelable_task_tracker_;
 
   // The Profile object is used to listen for events
   Profile* profile_;
@@ skipping 20 matching lines @@
   typedef std::pair<std::string, scoped_refptr<ShellLinkItem> > URLPair;
   std::list<URLPair> icon_urls_;
 
   // Id of last favicon task. It's used to cancel current task if a new one
   // comes in before it finishes.
   CancelableTaskTracker::TaskId task_id_;
 
   // 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_