Make largest_changestamp setter/getter asynchronous.

chrome/browser/chromeos/drive/drive_feed_loader.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_feed_loader.h"
 
 #include <set>
 
 #include "base/callback.h"
 #include "base/command_line.h"
@@ skipping 238 matching lines @@
 
 void DriveFeedLoader::RemoveObserver(DriveFeedLoaderObserver* observer) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
   observers_.RemoveObserver(observer);
 }
 
 void DriveFeedLoader::ReloadFromServerIfNeeded(
     const FileOperationCallback& callback) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
   DCHECK(!callback.is_null());
-  DVLOG(1) << "ReloadFromServerIfNeeded local_changestamp="
-           << resource_metadata_->largest_changestamp()
-           << ", loaded=" << resource_metadata_->loaded();
 
   // Sets the refreshing flag, so that the caller does not send refresh requests
   // in parallel (see DriveFileSystem::CheckForUpdates). Corresponding
   // "refresh_ = false" is in OnGetAccountMetadata when the cached feed is up to
   // date, or in OnFeedFromServerLoaded called back from LoadFromServer().
   refreshing_ = true;
 
   if (google_apis::util::IsDriveV2ApiEnabled()) {
     // Drive v2 needs a separate application list fetch operation.
     // TODO(haruki): Application list rarely changes and is not necessarily
@@ skipping 12 matching lines @@
 }
 
 void DriveFeedLoader::OnGetAccountMetadata(
     const FileOperationCallback& callback,
     google_apis::GDataErrorCode status,
     scoped_ptr<google_apis::AccountMetadataFeed> account_metadata) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
   DCHECK(!callback.is_null());
   DCHECK(refreshing_);
 
-  int64 local_changestamp = resource_metadata_->largest_changestamp();
   int64 remote_changestamp = 0;
-
   // When account metadata successfully fetched, parse the latest changestamp.
   if (util::GDataToDriveFileError(status) == DRIVE_FILE_OK) {
     DCHECK(account_metadata);
     webapps_registry_->UpdateFromFeed(*account_metadata);
     remote_changestamp = account_metadata->largest_changestamp();
   }
 
+  resource_metadata_->GetLargestChangestamp(
+      base::Bind(&DriveFeedLoader::CompareChangestamps,
+                 weak_ptr_factory_.GetWeakPtr(),
+                 callback,
+                 remote_changestamp));
+}
+
+void DriveFeedLoader::CompareChangestamps(
+    const FileOperationCallback& callback,
+    int64 remote_changestamp,
+    int64 local_changestamp) {
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
+  DCHECK(!callback.is_null());
+  DCHECK(refreshing_);
+
   if (remote_changestamp > 0 && local_changestamp >= remote_changestamp) {
     if (local_changestamp > remote_changestamp) {
       LOG(WARNING) << "Cached client feed is fresher than server, client = "
                    << local_changestamp
                    << ", server = "
                    << remote_changestamp;
     }
 
     // No changes detected, tell the client that the loading was successful.
     refreshing_ = false;
@@ skipping 372 matching lines @@
 
   // Run the callback now that the filesystem is ready.
   load_finished_callback.Run(DRIVE_FILE_OK);
 
   FOR_EACH_OBSERVER(DriveFeedLoaderObserver,
                     observers_,
                     OnFeedFromServerLoaded());
 }
 
 }  // namespace drive