[SyncFileSystem] Separate out ApplyLocalChange from DriveFileSyncService.

chrome/browser/sync_file_system/drive/apply_local_change_delegate.cc

Index: chrome/browser/sync_file_system/drive/apply_local_change_delegate.cc
diff --git a/chrome/browser/sync_file_system/drive/apply_local_change_delegate.cc b/chrome/browser/sync_file_system/drive/apply_local_change_delegate.cc
new file mode 100644
index 0000000000000000000000000000000000000000..183177e4c460828a4a1ec131d2e8b9337bc83f8b
--- /dev/null
+++ b/chrome/browser/sync_file_system/drive/apply_local_change_delegate.cc
@@ -0,0 +1,612 @@
+// 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/apply_local_change_delegate.h"
+
+#include "base/bind.h"
+#include "base/callback.h"
+#include "chrome/browser/sync_file_system/drive/api_util.h"
+#include "chrome/browser/sync_file_system/drive_file_sync_service.h"
+#include "chrome/browser/sync_file_system/drive_metadata_store.h"
+#include "webkit/fileapi/syncable/syncable_file_system_util.h"
+
+namespace sync_file_system {
+namespace drive {
+
+namespace {
+
+void OwnDelegateInstance(ApplyLocalChangeDelegate* delegate,
+                         const SyncStatusCallback& callback,
+                         SyncStatusCode status) {
+  callback.Run(status);
+}
+
+}  // namespace
+
+ApplyLocalChangeDelegate::~ApplyLocalChangeDelegate() {}
+
+ApplyLocalChangeDelegate::ApplyLocalChangeDelegate(

[kinuko, 2013/05/16 06:57:49]

nit: method order different from .h

[tzik, 2013/05/16 11:06:14]

Done.

+    base::WeakPtr<DriveFileSyncService> sync_service,
+    const FileChange& local_change,
+    const base::FilePath& local_path,
+    const SyncFileMetadata& local_metadata,
+    const fileapi::FileSystemURL& url)
+    : sync_service_(sync_service),
+      url_(url),
+      local_change_(local_change),
+      local_path_(local_path),
+      local_metadata_(local_metadata),
+      has_drive_metadata_(false),
+      has_remote_change_(false),
+      weak_factory_(this) {}
+
+void ApplyLocalChangeDelegate::ApplyLocalChange(
+    base::WeakPtr<DriveFileSyncService> sync_service,
+    const FileChange& local_change,
+    const base::FilePath& local_path,
+    const SyncFileMetadata& local_metadata,
+    const fileapi::FileSystemURL& url,
+    const SyncStatusCallback& callback) {
+  if (!sync_service)
+    return;
+
+  ApplyLocalChangeDelegate* delegate = new ApplyLocalChangeDelegate(
+      sync_service, local_change, local_path, local_metadata, url);
+  SyncStatusCallback completion_callback =
+      base::Bind(&OwnDelegateInstance, base::Owned(delegate), callback);

[kinuko, 2013/05/16 06:57:49]

I understand this class's very self-contained and looks clean, but as we chatted
offline it concerns me that we lose lifetime control once we launched. (E.g. we
may want to cancel an ongoing sync task, and in the current code there's no way
to do so other than killing SyncService).

[tzik, 2013/05/16 11:06:14]

Done. I added |running_local_sync_task_| to DriveFileSyncService to cancel the
task.

+  delegate->Run(completion_callback);
+}
+
+void ApplyLocalChangeDelegate::Run(const SyncStatusCallback& callback) {
+  if (!sync_service_)
+    return;
+
+  // TODO(nhiroki): support directory operations (http://crbug.com/161442).
+  DCHECK(IsSyncDirectoryOperationEnabled() || !local_change_.IsDirectory());
+
+  has_drive_metadata_ =
+      metadata_store()->ReadEntry(url_, &drive_metadata_) == SYNC_STATUS_OK;
+
+  if (!has_drive_metadata_)
+    drive_metadata_.set_md5_checksum(std::string());
+
+  sync_service_->EnsureOriginRootDirectory(
+      url_.origin(),
+      base::Bind(&ApplyLocalChangeDelegate::DidGetOriginRoot,
+                 weak_factory_.GetWeakPtr(),
+                 callback));
+}
+
+void ApplyLocalChangeDelegate::DidGetOriginRoot(
+    const SyncStatusCallback& callback,
+    SyncStatusCode status,
+    const std::string& origin_resource_id) {
+  if (!sync_service_)
+    return;
+
+  if (status != SYNC_STATUS_OK) {
+    callback.Run(status);
+    return;
+  }
+
+  origin_resource_id_ = origin_resource_id;
+
+  has_remote_change_ =
+      remote_change_handler()->GetChangeForURL(url_, &remote_change_);
+  if (has_remote_change_ && drive_metadata_.resource_id().empty())
+    drive_metadata_.set_resource_id(remote_change_.resource_id);
+
+  LocalSyncOperationType operation = LocalSyncOperationResolver::Resolve(
+      local_change_,
+      has_remote_change_ ? &remote_change_.change : NULL,
+      has_drive_metadata_ ? &drive_metadata_ : NULL);
+
+  DVLOG(1) << "ApplyLocalChange for " << url_.DebugString()
+           << " local_change:" << local_change_.DebugString()
+           << " ==> operation:" << operation;
+
+  switch (operation) {
+    case LOCAL_SYNC_OPERATION_ADD_FILE:
+      UploadNewFile(callback);
+      return;
+    case LOCAL_SYNC_OPERATION_ADD_DIRECTORY:
+      CreateDirectory(callback);
+      return;
+    case LOCAL_SYNC_OPERATION_UPDATE_FILE:
+      UploadExistingFile(callback);
+      return;
+    case LOCAL_SYNC_OPERATION_DELETE_FILE:
+      DeleteFile(callback);
+      return;
+    case LOCAL_SYNC_OPERATION_DELETE_DIRECTORY:
+      DeleteDirectory(callback);
+      return;
+    case LOCAL_SYNC_OPERATION_NONE:
+      callback.Run(SYNC_STATUS_OK);
+      return;
+    case LOCAL_SYNC_OPERATION_CONFLICT:
+      HandleConflict(callback);
+      return;
+    case LOCAL_SYNC_OPERATION_RESOLVE_TO_LOCAL:
+      ResolveToLocal(callback);
+      return;
+    case LOCAL_SYNC_OPERATION_RESOLVE_TO_REMOTE:
+      ResolveToRemote(callback);
+      return;
+    case LOCAL_SYNC_OPERATION_DELETE_METADATA:
+      DeleteMetadata(base::Bind(
+          &ApplyLocalChangeDelegate::DidApplyLocalChange,
+          weak_factory_.GetWeakPtr(), callback, google_apis::HTTP_SUCCESS));
+      return;
+    case LOCAL_SYNC_OPERATION_FAIL: {
+      callback.Run(SYNC_STATUS_FAILED);
+      return;
+    }
+  }
+  NOTREACHED();
+  callback.Run(SYNC_STATUS_FAILED);
+}
+
+void ApplyLocalChangeDelegate::UploadNewFile(
+    const SyncStatusCallback& callback) {
+  if (!sync_service_)
+    return;
+
+  api_util()->UploadNewFile(
+      origin_resource_id_,
+      local_path_,
+      DriveFileSyncService::PathToTitle(url_.path()),
+      base::Bind(&ApplyLocalChangeDelegate::DidUploadNewFile,
+                 weak_factory_.GetWeakPtr(), callback));
+}
+
+void ApplyLocalChangeDelegate::DidUploadNewFile(
+    const SyncStatusCallback& callback,
+    google_apis::GDataErrorCode error,
+    const std::string& resource_id,
+    const std::string& md5) {
+  if (!sync_service_)
+    return;
+
+  switch (error) {
+    case google_apis::HTTP_CREATED:
+      UpdateMetadata(
+          resource_id, md5, DriveMetadata::RESOURCE_TYPE_FILE,
+          base::Bind(&ApplyLocalChangeDelegate::DidApplyLocalChange,
+                     weak_factory_.GetWeakPtr(), callback, error));
+      sync_service_->NotifyObserversFileStatusChanged(
+          url_,
+          SYNC_FILE_STATUS_SYNCED,
+          SYNC_ACTION_ADDED,
+          SYNC_DIRECTION_LOCAL_TO_REMOTE);
+      return;
+    case google_apis::HTTP_CONFLICT:
+      HandleCreationConflict(resource_id, DriveMetadata::RESOURCE_TYPE_FILE,
+                             callback);
+      return;
+    default:
+      callback.Run(GDataErrorCodeToSyncStatusCodeWrapper(error));
+  }
+}
+
+void ApplyLocalChangeDelegate::CreateDirectory(
+    const SyncStatusCallback& callback) {
+  if (!sync_service_)
+    return;
+
+  DCHECK(IsSyncDirectoryOperationEnabled());
+  api_util()->CreateDirectory(
+      origin_resource_id_,
+      DriveFileSyncService::PathToTitle(url_.path()),
+      base::Bind(&ApplyLocalChangeDelegate::DidCreateDirectory,
+                 weak_factory_.GetWeakPtr(), callback));
+}
+
+void ApplyLocalChangeDelegate::DidCreateDirectory(
+    const SyncStatusCallback& callback,
+    google_apis::GDataErrorCode error,
+    const std::string& resource_id) {
+  if (!sync_service_)
+    return;
+
+  switch (error) {
+    case google_apis::HTTP_SUCCESS:
+    case google_apis::HTTP_CREATED: {
+      UpdateMetadata(
+          resource_id, std::string(), DriveMetadata::RESOURCE_TYPE_FOLDER,
+          base::Bind(&ApplyLocalChangeDelegate::DidApplyLocalChange,
+                     weak_factory_.GetWeakPtr(), callback, error));
+      sync_service_->NotifyObserversFileStatusChanged(
+          url_,
+          SYNC_FILE_STATUS_SYNCED,
+          SYNC_ACTION_ADDED,
+          SYNC_DIRECTION_LOCAL_TO_REMOTE);
+      return;
+    }
+
+    case google_apis::HTTP_CONFLICT:
+      // There were conflicts and a file was left.
+      // TODO(kinuko): Handle the latter case (http://crbug.com/237090).
+      // Fall-through
+
+    default:
+      callback.Run(GDataErrorCodeToSyncStatusCodeWrapper(error));
+  }
+}
+
+void ApplyLocalChangeDelegate::UploadExistingFile(
+    const SyncStatusCallback& callback) {
+  if (!sync_service_)
+    return;
+
+  DCHECK(has_drive_metadata_);
+  api_util()->UploadExistingFile(
+      drive_metadata_.resource_id(),
+      drive_metadata_.md5_checksum(),
+      local_path_,
+      base::Bind(&ApplyLocalChangeDelegate::DidUploadExistingFile,
+                 weak_factory_.GetWeakPtr(), callback));
+}
+
+void ApplyLocalChangeDelegate::DidUploadExistingFile(
+    const SyncStatusCallback& callback,
+    google_apis::GDataErrorCode error,
+    const std::string& resource_id,
+    const std::string& md5) {
+  if (!sync_service_)
+    return;
+
+  DCHECK(has_drive_metadata_);
+  switch (error) {
+    case google_apis::HTTP_SUCCESS:
+      UpdateMetadata(
+          resource_id, md5, DriveMetadata::RESOURCE_TYPE_FILE,
+          base::Bind(&ApplyLocalChangeDelegate::DidApplyLocalChange,
+                     weak_factory_.GetWeakPtr(), callback, error));
+      sync_service_->NotifyObserversFileStatusChanged(
+          url_,
+          SYNC_FILE_STATUS_SYNCED,
+          SYNC_ACTION_UPDATED,
+          SYNC_DIRECTION_LOCAL_TO_REMOTE);
+      return;
+    case google_apis::HTTP_CONFLICT: {
+      HandleConflict(callback);
+      return;
+    }
+    case google_apis::HTTP_NOT_MODIFIED: {
+      DidApplyLocalChange(callback,
+                          google_apis::HTTP_SUCCESS, SYNC_STATUS_OK);
+      return;
+    }
+    case google_apis::HTTP_NOT_FOUND: {
+      UploadNewFile(callback);
+      return;
+    }
+    default: {
+      const SyncStatusCode status =
+          GDataErrorCodeToSyncStatusCodeWrapper(error);
+      DCHECK_NE(SYNC_STATUS_OK, status);
+      callback.Run(status);
+      return;
+    }
+  }
+}
+
+void ApplyLocalChangeDelegate::DeleteFile(
+    const SyncStatusCallback& callback) {
+  if (!sync_service_)
+    return;
+
+  DCHECK(has_drive_metadata_);
+  api_util()->DeleteFile(
+      drive_metadata_.resource_id(),
+      drive_metadata_.md5_checksum(),
+      base::Bind(&ApplyLocalChangeDelegate::DidDeleteFile,
+                 weak_factory_.GetWeakPtr(), callback));
+}
+
+void ApplyLocalChangeDelegate::DeleteDirectory(
+    const SyncStatusCallback& callback) {
+  if (!sync_service_)
+    return;
+
+  DCHECK(IsSyncDirectoryOperationEnabled());
+  DCHECK(has_drive_metadata_);
+  // This does not handle recursive directory deletion
+  // (which should not happen other than after a restart).
+  api_util()->DeleteFile(
+      drive_metadata_.resource_id(),
+      std::string(),  // empty md5
+      base::Bind(&ApplyLocalChangeDelegate::DidDeleteFile,
+                 weak_factory_.GetWeakPtr(), callback));
+}
+
+void ApplyLocalChangeDelegate::DidDeleteFile(
+    const SyncStatusCallback& callback,
+    google_apis::GDataErrorCode error) {
+  if (!sync_service_)
+    return;
+
+  DCHECK(has_drive_metadata_);
+
+  switch (error) {
+    // Regardless of whether the deletion has succeeded (HTTP_SUCCESS) or
+    // has failed with ETag conflict error (HTTP_PRECONDITION or HTTP_CONFLICT)
+    // we should just delete the drive_metadata.
+    // In the former case the file should be just gone now, and
+    // in the latter case the remote change will be applied in a future
+    // remote sync.
+    case google_apis::HTTP_SUCCESS:
+    case google_apis::HTTP_PRECONDITION:
+    case google_apis::HTTP_CONFLICT:
+      DeleteMetadata(base::Bind(&ApplyLocalChangeDelegate::DidApplyLocalChange,
+                                weak_factory_.GetWeakPtr(), callback, error));
+      sync_service_->NotifyObserversFileStatusChanged(
+          url_,
+          SYNC_FILE_STATUS_SYNCED,
+          SYNC_ACTION_DELETED,
+          SYNC_DIRECTION_LOCAL_TO_REMOTE);
+      return;
+    case google_apis::HTTP_NOT_FOUND:
+      DidApplyLocalChange(callback,
+                          google_apis::HTTP_SUCCESS, SYNC_STATUS_OK);
+      return;
+    default: {
+      const SyncStatusCode status =
+          GDataErrorCodeToSyncStatusCodeWrapper(error);
+      DCHECK_NE(SYNC_STATUS_OK, status);
+      callback.Run(status);
+      return;
+    }
+  }
+}
+
+void ApplyLocalChangeDelegate::ResolveToLocal(
+    const SyncStatusCallback& callback) {
+  if (!sync_service_)
+    return;
+
+  api_util()->DeleteFile(
+      drive_metadata_.resource_id(),
+      drive_metadata_.md5_checksum(),
+      base::Bind(
+          &ApplyLocalChangeDelegate::DidDeleteFileToResolveToLocal,
+          weak_factory_.GetWeakPtr(), callback));
+}
+
+void ApplyLocalChangeDelegate::DidDeleteFileToResolveToLocal(
+    const SyncStatusCallback& callback,
+    google_apis::GDataErrorCode error) {
+  if (!sync_service_)
+    return;
+
+  if (error != google_apis::HTTP_SUCCESS &&
+      error != google_apis::HTTP_NOT_FOUND) {
+    remote_change_handler()->RemoveChangeForURL(url_);
+    callback.Run(GDataErrorCodeToSyncStatusCodeWrapper(error));
+    return;
+  }
+
+  DCHECK_NE(SYNC_FILE_TYPE_UNKNOWN, local_metadata_.file_type);
+  if (local_metadata_.file_type == SYNC_FILE_TYPE_FILE) {
+    UploadNewFile(callback);
+    return;
+  }
+
+  DCHECK(IsSyncDirectoryOperationEnabled());
+  DCHECK_EQ(SYNC_FILE_TYPE_DIRECTORY, local_metadata_.file_type);
+  CreateDirectory(callback);
+}
+
+void ApplyLocalChangeDelegate::ResolveToRemote(
+    const SyncStatusCallback& callback) {
+  if (!sync_service_)
+    return;
+
+  // Mark the file as to-be-fetched.
+  DCHECK(!drive_metadata_.resource_id().empty());
+
+  SyncFileType type = remote_change_.change.file_type();
+  SetToBeFetched(
+      drive_metadata_.resource_id(),
+      DriveFileSyncService::SyncFileTypeToDriveMetadataResourceType(type),
+      base::Bind(&ApplyLocalChangeDelegate::DidResolveToRemote,
+                 weak_factory_.GetWeakPtr(), callback));
+  // The synced notification will be dispatched when the remote file is
+  // downloaded.
+}
+
+void ApplyLocalChangeDelegate::DidResolveToRemote(
+    const SyncStatusCallback& callback,
+    SyncStatusCode status) {
+  if (!sync_service_)
+    return;
+
+  DCHECK(has_drive_metadata_);
+  if (status != SYNC_STATUS_OK) {
+    callback.Run(status);
+    return;
+  }
+
+  SyncFileType file_type = SYNC_FILE_TYPE_FILE;
+  if (drive_metadata_.type() == DriveMetadata::RESOURCE_TYPE_FOLDER)
+    file_type = SYNC_FILE_TYPE_DIRECTORY;
+  sync_service_->AppendFetchChange(
+      url_.origin(), url_.path(), drive_metadata_.resource_id(), file_type);
+  callback.Run(status);
+}
+
+void ApplyLocalChangeDelegate::DidApplyLocalChange(
+    const SyncStatusCallback& callback,
+    const google_apis::GDataErrorCode error,
+    SyncStatusCode status) {
+  if (!sync_service_)
+    return;
+
+  if (status == SYNC_STATUS_OK) {
+    remote_change_handler()->RemoveChangeForURL(url_);
+    status = GDataErrorCodeToSyncStatusCodeWrapper(error);
+  }
+  callback.Run(status);
+}
+
+void ApplyLocalChangeDelegate::UpdateMetadata(
+    const std::string& resource_id,
+    const std::string& md5,
+    DriveMetadata::ResourceType type,
+    const SyncStatusCallback& callback) {
+  if (!sync_service_)
+    return;
+
+  drive_metadata_.set_resource_id(resource_id);
+  drive_metadata_.set_md5_checksum(md5);
+  drive_metadata_.set_conflicted(false);
+  drive_metadata_.set_to_be_fetched(false);
+  drive_metadata_.set_type(type);
+  metadata_store()->UpdateEntry(url_, drive_metadata_, callback);
+}
+
+void ApplyLocalChangeDelegate::SetToBeFetched(
+    const std::string& resource_id,
+    DriveMetadata::ResourceType type,
+    const SyncStatusCallback& callback) {
+  if (!sync_service_)
+    return;
+
+  drive_metadata_.set_resource_id(resource_id);
+  drive_metadata_.set_md5_checksum(std::string());
+  drive_metadata_.set_conflicted(false);
+  drive_metadata_.set_to_be_fetched(true);
+  drive_metadata_.set_type(type);
+  metadata_store()->UpdateEntry(url_, drive_metadata_, callback);
+}
+
+void ApplyLocalChangeDelegate::SetConflict(
+    const std::string& resource_id,
+    const std::string& md5,
+    DriveMetadata::ResourceType type,
+    const SyncStatusCallback& callback) {
+  if (!sync_service_)
+    return;
+
+  drive_metadata_.set_resource_id(resource_id);
+  drive_metadata_.set_md5_checksum(md5);
+  drive_metadata_.set_conflicted(true);
+  drive_metadata_.set_to_be_fetched(false);
+  drive_metadata_.set_type(type);
+  metadata_store()->UpdateEntry(url_, drive_metadata_, callback);
+}
+
+void ApplyLocalChangeDelegate::DeleteMetadata(
+    const SyncStatusCallback& callback) {
+  metadata_store()->DeleteEntry(url_, callback);
+}
+
+void ApplyLocalChangeDelegate::HandleCreationConflict(
+    const std::string& resource_id,
+    DriveMetadata::ResourceType type,
+    const SyncStatusCallback& callback) {
+  if (!sync_service_)
+    return;
+
+  // File-file conflict is found.
+  // Populates a fake drive_metadata and set has_drive_metadata = true.
+  // In HandleConflictLocalSync:
+  // - If conflict_resolution is manual, we'll change conflicted to true
+  //   and save the metadata.
+  // - Otherwise we'll save the metadata with empty md5 and will start
+  //   over local sync as UploadExistingFile.
+  drive_metadata_.set_resource_id(resource_id);
+  drive_metadata_.set_md5_checksum(std::string());
+  drive_metadata_.set_conflicted(false);
+  drive_metadata_.set_to_be_fetched(false);
+  drive_metadata_.set_type(type);
+  has_drive_metadata_ = true;
+  HandleConflict(callback);
+}
+
+void ApplyLocalChangeDelegate::HandleConflict(
+    const SyncStatusCallback& callback) {
+  if (!sync_service_)
+    return;
+
+  DCHECK(!drive_metadata_.resource_id().empty());
+
+  api_util()->GetResourceEntry(
+      drive_metadata_.resource_id(),
+      base::Bind(
+          &ApplyLocalChangeDelegate::DidGetEntryForConflictResolution,
+          weak_factory_.GetWeakPtr(), callback));
+}
+
+void ApplyLocalChangeDelegate::DidGetEntryForConflictResolution(
+    const SyncStatusCallback& callback,
+    google_apis::GDataErrorCode error,
+    scoped_ptr<google_apis::ResourceEntry> entry) {
+  if (!sync_service_)
+    return;
+
+  SyncFileType local_file_type = local_metadata_.file_type;
+  base::Time local_modification_time = local_metadata_.last_modified;
+
+  SyncFileType remote_file_type;
+  base::Time remote_modification_time = entry->updated_time();
+  if (entry->is_file())
+    remote_file_type = SYNC_FILE_TYPE_FILE;
+  else if (entry->is_folder())
+    remote_file_type = SYNC_FILE_TYPE_DIRECTORY;
+  else
+    remote_file_type = SYNC_FILE_TYPE_UNKNOWN;
+
+  switch (sync_service_->ResolveConflictForLocalSync(
+      local_file_type, local_modification_time,
+      remote_file_type, remote_modification_time)) {
+    case DriveFileSyncService::CONFLICT_RESOLUTION_MARK_CONFLICT:
+      if (drive_metadata_.conflicted()) {
+        callback.Run(SYNC_STATUS_HAS_CONFLICT);
+        return;
+      }
+
+      SetConflict(drive_metadata_.resource_id(),
+                  drive_metadata_.md5_checksum(),
+                  DriveFileSyncService::SyncFileTypeToDriveMetadataResourceType(
+                      local_file_type),
+                  base::Bind(&ApplyLocalChangeDelegate::DidApplyLocalChange,
+                             weak_factory_.GetWeakPtr(), callback,
+                             google_apis::HTTP_SUCCESS));
+      return;
+    case DriveFileSyncService::CONFLICT_RESOLUTION_LOCAL_WIN:
+      DVLOG(1) << "Resolving conflict for local sync:"
+               << url_.DebugString() << ": LOCAL WIN";
+      ResolveToLocal(callback);
+      return;
+    case DriveFileSyncService::CONFLICT_RESOLUTION_REMOTE_WIN:
+      DVLOG(1) << "Resolving conflict for local sync:"
+               << url_.DebugString() << ": REMOTE WIN";
+      ResolveToRemote(callback);
+      return;
+  }
+  NOTREACHED();
+  callback.Run(SYNC_STATUS_FAILED);
+}
+
+SyncStatusCode ApplyLocalChangeDelegate::GDataErrorCodeToSyncStatusCodeWrapper(
+    google_apis::GDataErrorCode error) {
+  return sync_service_->GDataErrorCodeToSyncStatusCodeWrapper(error);
+}
+
+DriveMetadataStore* ApplyLocalChangeDelegate::metadata_store() {
+  return sync_service_->metadata_store_.get();
+}
+
+APIUtilInterface* ApplyLocalChangeDelegate::api_util() {
+  return sync_service_->api_util_.get();
+}
+
+RemoteChangeHandler* ApplyLocalChangeDelegate::remote_change_handler() {
+  return &sync_service_->remote_change_handler_;
+}
+
+}  // drive
+}  // namespace sync_file_system