sync: Implement per-type update processing

sync/engine/sync_directory_update_handler.cc

Index: sync/engine/sync_directory_update_handler.cc
diff --git a/sync/engine/sync_directory_update_handler.cc b/sync/engine/sync_directory_update_handler.cc
new file mode 100644
index 0000000000000000000000000000000000000000..e93b8bf6467fbac7b554407f438ee9c560d03b27
--- /dev/null
+++ b/sync/engine/sync_directory_update_handler.cc
@@ -0,0 +1,57 @@
+// Copyright (c) 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 "sync/engine/sync_directory_update_handler.h"
+
+#include "sync/engine/process_updates_util.h"
+#include "sync/sessions/status_controller.h"
+#include "sync/syncable/directory.h"
+#include "sync/syncable/syncable_model_neutral_write_transaction.h"
+
+namespace syncer {
+
+using syncable::SYNCER;
+
+SyncDirectoryUpdateHandler::SyncDirectoryUpdateHandler(
+    syncable::Directory* dir, ModelType type)
+  : dir_(dir),
+    type_(type) {}
+
+SyncDirectoryUpdateHandler::~SyncDirectoryUpdateHandler() {}
+
+void SyncDirectoryUpdateHandler::GetDownloadProgress(
+    sync_pb::DataTypeProgressMarker* progress_marker) const {
+  dir_->GetDownloadProgress(type_, progress_marker);
+}
+
+void SyncDirectoryUpdateHandler::ProcessGetUpdatesResponse(
+      const sync_pb::DataTypeProgressMarker& progress_marker,
+      const SyncEntityList& applicable_updates,
+      sessions::StatusController* status) {
+  syncable::ModelNeutralWriteTransaction trans(FROM_HERE, SYNCER, dir_);
+  UpdateSyncEntities(&trans, applicable_updates, status);
+  UpdateProgressMarkers(progress_marker);
+}
+
+void SyncDirectoryUpdateHandler::UpdateSyncEntities(
+    syncable::ModelNeutralWriteTransaction* trans,
+    const SyncEntityList& applicable_updates,
+    sessions::StatusController* status) {
+  ProcessDownloadedUpdates(dir_, trans, type_, applicable_updates, status);
+}
+
+void SyncDirectoryUpdateHandler::UpdateProgressMarkers(
+  const sync_pb::DataTypeProgressMarker& progress_marker) {
+  int field_number = progress_marker.data_type_id();
+  ModelType model_type = GetModelTypeFromSpecificsFieldNumber(field_number);
+  if (!IsRealDataType(model_type) || type_ != model_type) {
+    NOTREACHED()
+        << "Update handler of type " << ModelTypeToString(type_)
+        << " asked to process progress marker with invalid type "
+        << field_number;
+  }
+  dir_->SetDownloadProgress(type_, progress_marker);
+}
+
+}  // namespace syncer