Make largest_changestamp setter/getter asynchronous.

chrome/browser/chromeos/drive/drive_resource_metadata.cc

 // 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.
 
 #include "chrome/browser/chromeos/drive/drive_resource_metadata.h"
 
 #include <leveldb/db.h>
 #include <utility>
 
 #include "base/message_loop_proxy.h"
@@ skipping 212 matching lines @@
   // so we need to delete them here.
   root_->RemoveChildren();
   RemoveEntryFromResourceMap(root_->resource_id());
   DCHECK(resource_map_.empty());
   // The resource_map_ should be empty here, but to make sure for non-Debug
   // build.
   resource_map_.clear();
   root_.reset();
 }
 
+void DriveResourceMetadata::GetLargestChangestamp(
+    const GetChangestampCallback& callback) {
+  base::MessageLoopProxy::current()->PostTask(
+      FROM_HERE, base::Bind(callback, largest_changestamp_));
+}
+
+void DriveResourceMetadata::SetLargestChangestamp(
+    int64 value,
+    const FileOperationCallback& callback) {
+  largest_changestamp_ = value;
+  base::MessageLoopProxy::current()->PostTask(
+      FROM_HERE, base::Bind(callback, DRIVE_FILE_OK));
+}
+
 void DriveResourceMetadata::AddEntryToDirectory(
     const FilePath& directory_path,
     scoped_ptr<google_apis::ResourceEntry> entry,
     const FileMoveCallback& callback) {
   DCHECK(!directory_path.empty());
   DCHECK(!callback.is_null());
 
   if (!entry.get()) {
     PostFileMoveCallbackError(callback, DRIVE_FILE_ERROR_FAILED);
     return;
@@ skipping 679 matching lines @@
   DCHECK(result.get());
 
   result->second.path = second_path;
   result->second.error = error;
   result->second.proto = entry_proto.Pass();
 
   callback.Run(result.Pass());
 }
 
 }  // namespace drive