Worker changes to prepare for lock-free shutdown.

chrome/browser/sync/glue/password_model_worker.h

 // 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.
 
 #ifndef CHROME_BROWSER_SYNC_GLUE_PASSWORD_MODEL_WORKER_H_
 #define CHROME_BROWSER_SYNC_GLUE_PASSWORD_MODEL_WORKER_H_
 
 #include "sync/internal_api/public/engine/model_safe_worker.h"
 
 #include "base/basictypes.h"
 #include "base/callback_forward.h"
 #include "base/compiler_specific.h"
 #include "base/memory/ref_counted.h"
 
 class PasswordStore;
 
 namespace base {
 class WaitableEvent;
 }
 
 namespace browser_sync {
 
 // A syncer::ModelSafeWorker for password models that accepts requests
 // from the syncapi that need to be fulfilled on the password thread,
 // which is the DB thread on Linux and Windows.
 class PasswordModelWorker : public syncer::ModelSafeWorker {
  public:
-  explicit PasswordModelWorker(
-      const scoped_refptr<PasswordStore>& password_store);
+  PasswordModelWorker(const scoped_refptr<PasswordStore>& password_store,
+                      syncer::WorkerLoopDestructionObserver* observer);
 
   // syncer::ModelSafeWorker implementation. Called on syncapi SyncerThread.
-  virtual syncer::SyncerError DoWorkAndWaitUntilDone(
+  virtual void RegisterForLoopDestruction() OVERRIDE;
+  virtual syncer::ModelSafeGroup GetModelSafeGroup() OVERRIDE;
+
+ protected:
+  virtual syncer::SyncerError DoWorkAndWaitUntilDoneImpl(
       const syncer::WorkCallback& work) OVERRIDE;
-  virtual syncer::ModelSafeGroup GetModelSafeGroup() OVERRIDE;
 
  private:
   virtual ~PasswordModelWorker();
 
   void CallDoWorkAndSignalTask(
     const syncer::WorkCallback& work,
     base::WaitableEvent* done,
     syncer::SyncerError* error);
 
+  // Called on password thread to add PasswordModelWorker as destruction
+  // observer.
+  void RegisterForPasswordLoopDestruction();
+
   scoped_refptr<PasswordStore> password_store_;
   DISALLOW_COPY_AND_ASSIGN(PasswordModelWorker);
 };
 
 }  // namespace browser_sync
 
 #endif  // CHROME_BROWSER_SYNC_GLUE_PASSWORD_MODEL_WORKER_H_