Make largest_changestamp setter/getter asynchronous.

chrome/browser/chromeos/drive/drive_resource_metadata.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_DRIVE_DRIVE_RESOURCE_METADATA_H_
 #define CHROME_BROWSER_CHROMEOS_DRIVE_DRIVE_RESOURCE_METADATA_H_
 
 #include <map>
 #include <set>
 #include <string>
@@ skipping 72 matching lines @@
 // directory names).
 typedef base::Callback<void(DriveFileError error,
                             const FilePath& drive_file_path,
                             scoped_ptr<DriveEntryProto> entry_proto)>
     GetEntryInfoWithFilePathCallback;
 
 // Used to get a set of changed directories for feed processing.
 typedef base::Callback<void(const std::set<FilePath>&)>
     GetChildDirectoriesCallback;
 
+typedef base::Callback<void(int64)> GetChangestampCallback;
+
 // This is a part of EntryInfoPairResult.
 struct EntryInfoResult {
   EntryInfoResult();
   ~EntryInfoResult();
 
   FilePath path;
   DriveFileError error;
   scoped_ptr<DriveEntryProto> proto;
 };
 
@@ skipping 22 matching lines @@
   DriveResourceMetadata();
   ~DriveResourceMetadata();
 
   // Last time when we dumped serialized file system to disk.
   const base::Time& last_serialized() const { return last_serialized_; }
   void set_last_serialized(const base::Time& time) { last_serialized_ = time; }
   // Size of serialized file system on disk in bytes.
   size_t serialized_size() const { return serialized_size_; }
   void set_serialized_size(size_t size) { serialized_size_ = size; }
 
-  // Largest change timestamp that was the source of content for the current
-  // state of the root directory.
-  int64 largest_changestamp() const { return largest_changestamp_; }
-  void set_largest_changestamp(int64 value) { largest_changestamp_ = value; }
-
   // True if the file system feed is loaded from the cache or from the server.
   bool loaded() const { return loaded_; }
   void set_loaded(bool loaded) { loaded_ = loaded; }
 
+  // Largest change timestamp that was the source of content for the current
+  // state of the root directory.
+  void GetLargestChangestamp(const GetChangestampCallback& callback);
+  void SetLargestChangestamp(int64 value,
+                             const FileOperationCallback& callback);
+
   // Add |entry| to directory with path |directory_path| and invoke the
   // callback asynchronously.
   // |callback| must not be null.
   void AddEntryToDirectory(const FilePath& directory_path,
                            scoped_ptr<google_apis::ResourceEntry> entry,
                            const FileMoveCallback& callback);
 
   // Add |entry_proto| to the metadata tree, based on its parent_resource_id.
   // |callback| must not be null.
   void AddEntryToParent(const DriveEntryProto& entry_proto,
@@ skipping 163 matching lines @@
   // This should remain the last member so it'll be destroyed first and
   // invalidate its weak pointers before other members are destroyed.
   base::WeakPtrFactory<DriveResourceMetadata> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(DriveResourceMetadata);
 };
 
 }  // namespace drive
 
 #endif  // CHROME_BROWSER_CHROMEOS_DRIVE_DRIVE_RESOURCE_METADATA_H_