Avoid useless SYNC_CYCLE_CONTINUATION sync cycle

chrome/browser/sync/engine/model_changing_syncer_command_unittest.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 "base/basictypes.h"
 #include "base/compiler_specific.h"
 #include "base/memory/ref_counted.h"
 #include "chrome/browser/sync/engine/model_changing_syncer_command.h"
 #include "chrome/browser/sync/sessions/sync_session.h"
 #include "chrome/browser/sync/syncable/model_type.h"
@@ skipping 13 matching lines @@
   const std::set<ModelSafeGroup>& changed_groups() const {
     return changed_groups_;
   }
 
  protected:
   virtual std::set<ModelSafeGroup> GetGroupsToChange(
       const sessions::SyncSession& session) const OVERRIDE {
     return session.GetEnabledGroups();
   }
 
-  virtual void ModelChangingExecuteImpl(
+  virtual SyncerError ModelChangingExecuteImpl(
       sessions::SyncSession* session) OVERRIDE {
     changed_groups_.insert(session->status_controller().group_restriction());
+    return NO_ERROR;
   }
 
  private:
   std::set<ModelSafeGroup> changed_groups_;
 
   DISALLOW_COPY_AND_ASSIGN(FakeModelChangingSyncerCommand);
 };
 
 class ModelChangingSyncerCommandTest : public SyncerCommandTest {
  protected:
@@ skipping 20 matching lines @@
   ExpectGroupsToChange(command_, GROUP_UI, GROUP_PASSWORD, GROUP_PASSIVE);
   EXPECT_TRUE(command_.changed_groups().empty());
   command_.ExecuteImpl(session());
   EXPECT_EQ(command_.GetGroupsToChangeForTest(*session()),
             command_.changed_groups());
 }
 
 }  // namespace
 
 }  // namespace browser_sync