RefCounted types should not have public destructors, chrome/browser/ part 2

chrome/browser/sync/glue/history_model_worker.cc

 // 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.
 
 #include "chrome/browser/sync/glue/history_model_worker.h"
 
 #include "base/memory/ref_counted.h"
 #include "base/message_loop.h"
 #include "base/synchronization/waitable_event.h"
 #include "chrome/browser/history/history.h"
@@ skipping 15 matching lines @@
     *error_ = work_.Run();
     done_->Signal();
     return true;
   }
 
   // Since the DoWorkAndWaitUntilDone() is syncronous, we don't need to run any
   // code asynchronously on the main thread after completion.
   virtual void DoneRunOnMainThread() {}
 
  protected:
+  virtual ~WorkerTask() {}
+
   WorkCallback work_;
   WaitableEvent* done_;
   SyncerError* error_;
 };
 
 
 HistoryModelWorker::HistoryModelWorker(HistoryService* history_service)
   : history_service_(history_service) {
   CHECK(history_service);
 }
 
-HistoryModelWorker::~HistoryModelWorker() {
-}
-
 SyncerError HistoryModelWorker::DoWorkAndWaitUntilDone(
     const WorkCallback& work) {
   WaitableEvent done(false, false);
   SyncerError error = UNSET;
   scoped_refptr<WorkerTask> task(new WorkerTask(work, &done, &error));
   history_service_->ScheduleDBTask(task.get(), &cancelable_consumer_);
   done.Wait();
   return error;
 }
 
 ModelSafeGroup HistoryModelWorker::GetModelSafeGroup() {
   return GROUP_HISTORY;
 }
 
+HistoryModelWorker::~HistoryModelWorker() {}
+
 }  // namespace browser_sync