[Sync] ModelTypeStore::ReadMetadataCallback now returns a MetadataBatch

components/sync/device_info/device_info_sync_bridge.cc

 // Copyright 2015 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 "components/sync/device_info/device_info_sync_bridge.h"
 
 #include <stdint.h>
 
 #include <algorithm>
 #include <set>
@@ skipping 350 matching lines @@
 }
 
 void DeviceInfoSyncBridge::LoadMetadataIfReady() {
   if (has_data_loaded_ && has_provider_initialized_) {
     store_->ReadAllMetadata(base::Bind(&DeviceInfoSyncBridge::OnReadAllMetadata,
                                        base::AsWeakPtr(this)));
   }
 }
 
 void DeviceInfoSyncBridge::OnReadAllMetadata(
-    Result result,
-    std::unique_ptr<RecordList> metadata_records,
-    const std::string& global_metadata) {
-  if (result != Result::SUCCESS) {
-    ReportStartupErrorToSync("Load of metadata completely failed.");
-    return;
-  }
-
-  auto batch = base::MakeUnique<MetadataBatch>();
-  ModelTypeState state;
-  if (state.ParseFromString(global_metadata)) {
-    batch->SetModelTypeState(state);
-  } else {
-    ReportStartupErrorToSync("Failed to deserialize global metadata.");
-    return;
-  }
-
-  for (const Record& r : *metadata_records.get()) {
-    sync_pb::EntityMetadata entity_metadata;
-    if (entity_metadata.ParseFromString(r.value)) {
-      batch->AddMetadata(r.id, entity_metadata);
-    } else {
-      ReportStartupErrorToSync("Failed to deserialize entity metadata.");
-    }
-  }
-
-  change_processor()->OnMetadataLoaded(SyncError(), std::move(batch));
+    SyncError error,
+    std::unique_ptr<MetadataBatch> metadata_batch) {
+  change_processor()->OnMetadataLoaded(error, std::move(metadata_batch));

[skym, 2016/11/05 00:45:42]

So much less code!

However, this is perpetuating the pattern where ModelTypeProcessor methods take
SyncError objects.

[maxbogue, 2016/11/07 17:03:39]

Eh, doesn't make it any harder to get rid of in the future.

   ReconcileLocalAndStored();
 }
 
 void DeviceInfoSyncBridge::OnCommit(Result result) {
   if (result != Result::SUCCESS) {
     change_processor()->CreateAndUploadError(FROM_HERE,
                                              "Failed a write to store.");
   }
 }
 
@@ skipping 71 matching lines @@
 }
 
 void DeviceInfoSyncBridge::ReportStartupErrorToSync(const std::string& msg) {
   // TODO(skym): Shouldn't need to log this here, reporting should always log.
   LOG(WARNING) << msg;
   change_processor()->OnMetadataLoaded(
       change_processor()->CreateAndUploadError(FROM_HERE, msg), nullptr);
 }
 
 }  // namespace syncer