[Sync] Refactor sync datatype error handling.

chrome/browser/sync/glue/app_model_associator.cc

 // Copyright (c) 2011 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/glue/app_model_associator.h"
 
 #include "base/logging.h"
 #include "base/tracked.h"
 #include "chrome/browser/extensions/extension_sync_data.h"
+#include "chrome/browser/sync/api/sync_error.h"
 #include "chrome/browser/sync/engine/syncapi.h"
 #include "chrome/browser/sync/glue/extension_sync_traits.h"
 #include "chrome/browser/sync/glue/extension_sync.h"
 #include "chrome/browser/sync/profile_sync_service.h"
 #include "chrome/browser/sync/protocol/extension_specifics.pb.h"
 #include "chrome/browser/sync/syncable/nigori_util.h"
 #include "content/browser/browser_thread.h"
 
 namespace browser_sync {
 
 AppModelAssociator::AppModelAssociator(
     ExtensionServiceInterface* extension_service,
     sync_api::UserShare* user_share)
     : traits_(GetAppSyncTraits()), extension_service_(extension_service),
       user_share_(user_share) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
   DCHECK(extension_service_);
   DCHECK(user_share_);
 }
 
 AppModelAssociator::~AppModelAssociator() {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
 }
 
-bool AppModelAssociator::AssociateModels() {
+bool AppModelAssociator::AssociateModels(SyncError* error) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
   ExtensionDataMap extension_data_map;
   if (!SlurpExtensionData(
           traits_, *extension_service_, user_share_, &extension_data_map)) {
+    error->reset(FROM_HERE, "Failed to get app data.", model_type());
     return false;
   }
   if (!FlushExtensionData(
           traits_, extension_data_map, extension_service_, user_share_)) {
+    error->reset(FROM_HERE, "Failed to flush app data.", model_type());
     return false;
   }
 
   return true;
 }
 
-bool AppModelAssociator::DisassociateModels() {
+bool AppModelAssociator::DisassociateModels(SyncError* error) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
   // Nothing to do.
   return true;
 }
 
 bool AppModelAssociator::SyncModelHasUserCreatedNodes(bool* has_nodes) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
   return RootNodeHasChildren(traits_.root_node_tag, user_share_, has_nodes);
 }
 
 void AppModelAssociator::AbortAssociation() {
   // No implementation needed, this associator runs on the main
   // thread.
 }
 
 bool AppModelAssociator::CryptoReadyIfNecessary() {
   // We only access the cryptographer while holding a transaction.
   sync_api::ReadTransaction trans(FROM_HERE, user_share_);
   const syncable::ModelTypeSet& encrypted_types =
       sync_api::GetEncryptedTypes(&trans);
   return encrypted_types.count(traits_.model_type) == 0 ||
       trans.GetCryptographer()->is_ready();
 }
 
 }  // namespace browser_sync