Add return values to SyncerCommand

chrome/browser/sync/engine/build_and_process_conflict_sets_command.cc

Index: chrome/browser/sync/engine/build_and_process_conflict_sets_command.cc
diff --git a/chrome/browser/sync/engine/build_and_process_conflict_sets_command.cc b/chrome/browser/sync/engine/build_and_process_conflict_sets_command.cc
index 065f021af8efe36e8ad9135c703fd2ef246122bd..b4fc41e645fdd26172893d500c71af9ad8ff8072 100644
--- a/chrome/browser/sync/engine/build_and_process_conflict_sets_command.cc
+++ b/chrome/browser/sync/engine/build_and_process_conflict_sets_command.cc
@@ -1,4 +1,4 @@
-// Copyright (c) 2011 The Chromium Authors. All rights reserved.
+// Copyright (c) 2012 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.
 
@@ -35,10 +35,11 @@ std::set<ModelSafeGroup> BuildAndProcessConflictSetsCommand::GetGroupsToChange(
   return session.GetEnabledGroupsWithConflicts();
 }
 
-void BuildAndProcessConflictSetsCommand::ModelChangingExecuteImpl(
+SyncerError BuildAndProcessConflictSetsCommand::ModelChangingExecuteImpl(
     SyncSession* session) {
   session->mutable_status_controller()->update_conflict_sets_built(
       BuildAndProcessConflictSets(session));
+  return SYNCER_OK;
 }
 
 bool BuildAndProcessConflictSetsCommand::BuildAndProcessConflictSets(