[SyncFS] Make MetadataDatabase operations synchronous

chrome/browser/sync_file_system/drive_backend/remote_to_local_syncer.cc

 // Copyright 2013 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/sync_file_system/drive_backend/remote_to_local_syncer.h"
 
 #include "base/bind.h"
 #include "base/callback.h"
 #include "base/files/file_util.h"
 #include "base/format_macros.h"
@@ skipping 297 matching lines @@
   DCHECK(sync_context_->GetWorkerTaskRunner()->RunsTasksOnCurrentThread());
 
   SyncStatusCode status = GDataErrorCodeToSyncStatusCode(error);
   if (status != SYNC_STATUS_OK &&
       error != google_apis::HTTP_NOT_FOUND) {
     SyncCompleted(token.Pass(), status);
     return;
   }
 
   if (error == google_apis::HTTP_NOT_FOUND) {
-    metadata_database()->UpdateByDeletedRemoteFile(
-        dirty_tracker_->file_id(), SyncCompletedCallback(token.Pass()));
+    status = metadata_database()->UpdateByDeletedRemoteFile(
+        dirty_tracker_->file_id());
+    SyncCompleted(token.Pass(), status);
     return;
   }
 
   if (!entry) {
     NOTREACHED();
     SyncCompleted(token.Pass(), SYNC_STATUS_FAILED);
     return;
   }
 
-  metadata_database()->UpdateByFileResource(
-      *entry,
-      base::Bind(&RemoteToLocalSyncer::DidUpdateDatabaseForRemoteMetadata,
-                 weak_ptr_factory_.GetWeakPtr(),
-                 base::Passed(&token)));
+  status = metadata_database()->UpdateByFileResource(*entry);
+  // TODO(tzik): Expand this function.
+  DidUpdateDatabaseForRemoteMetadata(token.Pass(), status);
 }
 
 void RemoteToLocalSyncer::DidUpdateDatabaseForRemoteMetadata(
     scoped_ptr<SyncTaskToken> token,
     SyncStatusCode status) {
   if (status != SYNC_STATUS_OK) {
     SyncCompleted(token.Pass(), status);
     return;
   }
 
@@ skipping 233 matching lines @@
 
   if (!file_list->next_link().is_empty()) {
     drive_service()->GetRemainingFileList(
         file_list->next_link(),
         base::Bind(&RemoteToLocalSyncer::DidListFolderContent,
                    weak_ptr_factory_.GetWeakPtr(),
                    base::Passed(&token), base::Passed(&children)));
     return;
   }
 
-  metadata_database()->PopulateFolderByChildList(
-      dirty_tracker_->file_id(), *children,
-      SyncCompletedCallback(token.Pass()));
+  status = metadata_database()->PopulateFolderByChildList(
+      dirty_tracker_->file_id(), *children);
+  SyncCompleted(token.Pass(), status);
 }
 
 void RemoteToLocalSyncer::SyncCompleted(scoped_ptr<SyncTaskToken> token,
                                         SyncStatusCode status) {
   token->RecordLog(base::StringPrintf(
       "[Remote -> Local]: Finished: action=%s, tracker=%" PRId64 " status=%s",
       SyncActionToString(sync_action_), dirty_tracker_->tracker_id(),
       SyncStatusCodeToString(status)));
 
   if (sync_root_deletion_) {
@@ skipping 20 matching lines @@
       HasDisabledAppRoot(metadata_database(), *dirty_tracker_)) {
     // Operations for an inactive tracker don't update file content.
     if (dirty_tracker_->has_synced_details())
       updated_details.set_md5(dirty_tracker_->synced_details().md5());
     if (!dirty_tracker_->active()) {
       // Keep missing true, as the change hasn't been synced to local.
       updated_details.clear_md5();
       updated_details.set_missing(true);
     }
   }
-  metadata_database()->UpdateTracker(
-      dirty_tracker_->tracker_id(),
-      updated_details,
-      base::Bind(&RemoteToLocalSyncer::FinalizeSync,
-                 weak_ptr_factory_.GetWeakPtr(),
-                 base::Passed(&token)));
+
+  status = metadata_database()->UpdateTracker(
+      dirty_tracker_->tracker_id(), updated_details);
+  // TODO(tzik): Expand this function.
+  FinalizeSync(token.Pass(), status);
 }
 
 void RemoteToLocalSyncer::FinalizeSync(scoped_ptr<SyncTaskToken> token,
                                        SyncStatusCode status) {
   if (prepared_) {
     remote_change_processor()->FinalizeRemoteSync(
         url_, false /* clear_local_change */,
         base::Bind(SyncTaskManager::NotifyTaskDone,
                    base::Passed(&token), status));
     return;
@@ skipping 116 matching lines @@
 
 SyncStatusCallback RemoteToLocalSyncer::SyncCompletedCallback(
     scoped_ptr<SyncTaskToken> token) {
   return base::Bind(&RemoteToLocalSyncer::SyncCompleted,
                     weak_ptr_factory_.GetWeakPtr(),
                     base::Passed(&token));
 }
 
 }  // namespace drive_backend
 }  // namespace sync_file_system