gdata: Add requestDirectoryRefresh to file_browser_private.

chrome/browser/chromeos/gdata/gdata_file_system.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_FILE_SYSTEM_H_
 #define CHROME_BROWSER_CHROMEOS_GDATA_GDATA_FILE_SYSTEM_H_
 #pragma once
 
 #include <sys/stat.h>
 
@@ skipping 347 matching lines @@
                                       const GetFileInfoCallback& callback) = 0;
 
   // Finds and reads a directory by |file_path|. This call will also retrieve
   // and refresh file system content from server and disk cache.
   //
   // Can be called from UI/IO thread. |callback| is run on the calling thread.
   virtual void ReadDirectoryByPathAsync(
       const FilePath& file_path,
       const ReadDirectoryCallback& callback) = 0;
 
+  // Requests a refresh of the directory pointed by |file_path| (i.e. fetches
+  // the latest metadata of files in the target directory).
+  //
+  // In particular, this function is used to get the latest thumbnail
+  // URLs. Thumbnail URLs change periodically even if contents of files are
+  // not changed, hence we should get the new thumbnail URLs manually if we
+  // detect that the existing thumnail URLs are stale.
+  //
+  // Upon success, the metadata of files in the target directory is updated,
+  // and the change is notified via Observer::OnDirectoryChanged(). Note that
+  // this function ignores changes in directories in the target
+  // directory. Changes in directories are handled via the delta feeds.
+  //
+  // Can be called from UI/IO thread.
+  virtual void RequestDirectoryRefresh(const FilePath& file_path) = 0;
+
   // Does server side content search for |search_query|. Search results will be
   // returned as gdata entries in temp directory proto, and their
   // title/file_name will be formatted as |<resource_id>.<original_file_name>|.
   //
   // Can be called from UI/IO thread. |callback| is run on the calling thread.
   virtual void SearchAsync(const std::string& search_query,
                            const ReadDirectoryCallback& callback) = 0;
 
 
   // Finds a file (not a directory) by |file_path| and returns its key
@@ skipping 99 matching lines @@
                              const GetCacheStateCallback& callback) OVERRIDE;
   virtual void GetEntryInfoByPathAsync(
       const FilePath& file_path,
       const GetEntryInfoCallback& callback) OVERRIDE;
   virtual void GetFileInfoByPathAsync(
       const FilePath& file_path,
       const GetFileInfoCallback& callback) OVERRIDE;
   virtual void ReadDirectoryByPathAsync(
       const FilePath& file_path,
       const ReadDirectoryCallback& callback) OVERRIDE;
+  virtual void RequestDirectoryRefresh(
+      const FilePath& file_path) OVERRIDE;
   virtual bool GetFileInfoByPath(const FilePath& file_path,
                                  GDataFileProperties* properties) OVERRIDE;
   virtual bool IsUnderGDataCacheDirectory(const FilePath& path) const OVERRIDE;
   virtual FilePath GetCacheDirectoryPath(
       GDataRootDirectory::CacheSubDirectoryType sub_dir_type) const OVERRIDE;
   virtual FilePath GetCacheFilePath(
       const std::string& resource_id,
       const std::string& md5,
       GDataRootDirectory::CacheSubDirectoryType sub_dir_type,
       CachedFileOrigin file_orign) const OVERRIDE;
@@ skipping 898 matching lines @@
       const GetDownloadDataCallback& get_download_data_callback);
   void GetEntryInfoByPathAsyncOnUIThread(
       const FilePath& file_path,
       const GetEntryInfoCallback& callback);
   void GetFileInfoByPathAsyncOnUIThread(
       const FilePath& file_path,
       const GetFileInfoCallback& callback);
   void ReadDirectoryByPathAsyncOnUIThread(
       const FilePath& file_path,
       const ReadDirectoryCallback& callback);
+  void RequestDirectoryRefreshOnUIThread(
+      const FilePath& file_path);
+  void OnRequestDirectoryRefresh(GetDocumentsParams* params,
+                                 base::PlatformFileError error);
   void GetCacheStateOnUIThread(const std::string& resource_id,
                                const std::string& md5,
                                const GetCacheStateCallback& callback);
   void GetAvailableSpaceOnUIThread(const GetAvailableSpaceCallback& callback);
   void SetPinStateOnUIThread(const FilePath& file_path, bool to_pin,
                              const FileOperationCallback& callback);
   void SetMountedStateOnUIThread(
       const FilePath& file_path,
       bool to_mount,
       const SetMountedStateCallback& callback);
@@ skipping 62 matching lines @@
 };
 
 // Sets the free disk space getter for testing.
 // The existing getter is deleted.
 void SetFreeDiskSpaceGetterForTesting(
     FreeDiskSpaceGetterInterface* getter);
 
 }  // namespace gdata
 
 #endif  // CHROME_BROWSER_CHROMEOS_GDATA_GDATA_FILE_SYSTEM_H_