gdata: Implement periodic file system update checks.

chrome/browser/chromeos/gdata/gdata_files.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_CHROMEOS_GDATA_GDATA_FILES_H_
 #define CHROME_BROWSER_CHROMEOS_GDATA_GDATA_FILES_H_
 #pragma once
 
 #include <map>
 #include <string>
@@ skipping 306 matching lines @@
 
   // Find a child by its name.
   GDataEntry* FindChild(const FilePath::StringType& file_name) const;
 
   // Removes the entry from its children list and destroys the entry instance.
   bool RemoveEntry(GDataEntry* entry);
 
   // Removes children elements.
   void RemoveChildren();
 
-  // Checks if directory content needs to be refreshed from the server.
-  bool NeedsRefresh() const;
-
   // Last refresh time.
   const base::Time& refresh_time() const { return refresh_time_; }
   void set_refresh_time(const base::Time& time) { refresh_time_ = time; }
   // Url for this feed.
   const GURL& start_feed_url() const { return start_feed_url_; }
   void set_start_feed_url(const GURL& url) { start_feed_url_ = url; }
   // Continuing feed's url.
   const GURL& next_feed_url() const { return next_feed_url_; }
   void set_next_feed_url(const GURL& url) { next_feed_url_ = url; }
   // Upload url is an entry point for initialization of file upload.
@@ skipping 162 matching lines @@
   base::Time last_serialized_;
   int largest_changestamp_;
   size_t serialized_size_;
 
   DISALLOW_COPY_AND_ASSIGN(GDataRootDirectory);
 };
 
 }  // namespace gdata
 
 #endif  // CHROME_BROWSER_CHROMEOS_GDATA_GDATA_FILES_H_