[Sync] Refactor sync datatype error handling.

chrome/browser/prefs/pref_model_associator.h

 // 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.
 
 #ifndef CHROME_BROWSER_PREFS_PREF_MODEL_ASSOCIATOR_H_
 #define CHROME_BROWSER_PREFS_PREF_MODEL_ASSOCIATOR_H_
 #pragma once
 
 #include <map>
 #include <set>
@@ skipping 19 matching lines @@
 // PrefService from the local state PrefService.
 class PrefModelAssociator
     : public SyncableService,
       public base::NonThreadSafe {
  public:
   explicit PrefModelAssociator(PrefService* pref_service);
   virtual ~PrefModelAssociator();
 
   // SyncableService implementation.
   virtual SyncDataList GetAllSyncData(syncable::ModelType type) const OVERRIDE;
-  virtual void ProcessSyncChanges(const tracked_objects::Location& from_here,
-                                  const SyncChangeList& change_list) OVERRIDE;
-  virtual bool MergeDataAndStartSyncing(
+  virtual SyncError ProcessSyncChanges(
+      const tracked_objects::Location& from_here,
+      const SyncChangeList& change_list) OVERRIDE;
+  virtual SyncError MergeDataAndStartSyncing(
       syncable::ModelType type,
       const SyncDataList& initial_sync_data,
       SyncChangeProcessor* sync_processor) OVERRIDE;
   virtual void StopSyncing(syncable::ModelType type) OVERRIDE;
 
   // Returns the list of preference names that are registered as syncable, and
   // hence should be monitored for changes.
   std::set<std::string> registered_preferences() const;
 
   // Register a preference with the specified name for syncing. We do not care
@@ skipping 87 matching lines @@
   // The PrefService we are syncing to.
   PrefService* pref_service_;
 
   // Sync's SyncChange handler. We push all our changes through this.
   SyncChangeProcessor* sync_processor_;
 
   DISALLOW_COPY_AND_ASSIGN(PrefModelAssociator);
 };
 
 #endif  // CHROME_BROWSER_PREFS_PREF_MODEL_ASSOCIATOR_H_