Release password store on UI loop when worker is stopped so that password

chrome/browser/sync/glue/password_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/password_model_worker.h"
 
 #include "base/bind.h"
 #include "base/memory/ref_counted.h"
 #include "base/synchronization/waitable_event.h"
 #include "chrome/browser/password_manager/password_store.h"
 
 using base::WaitableEvent;
 
 namespace browser_sync {
 
 PasswordModelWorker::PasswordModelWorker(
     const scoped_refptr<PasswordStore>& password_store,
     syncer::WorkerLoopDestructionObserver* observer)
   : syncer::ModelSafeWorker(observer),
     password_store_(password_store) {
   DCHECK(password_store.get());
 }
 
 void PasswordModelWorker::RegisterForLoopDestruction() {
+  base::AutoLock lock(password_store_lock_);
   password_store_->ScheduleTask(
       base::Bind(&PasswordModelWorker::RegisterForPasswordLoopDestruction,
                  this));
 }
 
 syncer::SyncerError PasswordModelWorker::DoWorkAndWaitUntilDoneImpl(
     const syncer::WorkCallback& work) {
   syncer::SyncerError error = syncer::UNSET;
-  if (password_store_->ScheduleTask(
-          base::Bind(&PasswordModelWorker::CallDoWorkAndSignalTask,
-                     this, work, work_done_or_stopped(), &error))) {
+
+  bool scheduled = false;
+  {
+    base::AutoLock lock(password_store_lock_);
+    if (!password_store_.get())
+      return syncer::CANNOT_DO_WORK;
+
+    scheduled = password_store_->ScheduleTask(
+        base::Bind(&PasswordModelWorker::CallDoWorkAndSignalTask,
+                   this, work, work_done_or_stopped(), &error));
+  }
+
+  if (scheduled)
     work_done_or_stopped()->Wait();
-  } else {
+  else
     error = syncer::CANNOT_DO_WORK;
-  }
   return error;
 }
 
 syncer::ModelSafeGroup PasswordModelWorker::GetModelSafeGroup() {
   return syncer::GROUP_PASSWORD;
 }
 
 PasswordModelWorker::~PasswordModelWorker() {}
 
 void PasswordModelWorker::CallDoWorkAndSignalTask(
     const syncer::WorkCallback& work,
     WaitableEvent* done,
     syncer::SyncerError *error) {
   *error = work.Run();
   done->Signal();
 }
 
 void PasswordModelWorker::RegisterForPasswordLoopDestruction() {
   base::MessageLoop::current()->AddDestructionObserver(this);
   SetWorkingLoopToCurrent();
 }
 
+void PasswordModelWorker::RequestStop() {
+  ModelSafeWorker::RequestStop();
+
+  base::AutoLock lock(password_store_lock_);
+  password_store_ = NULL;
+}
+
 }  // namespace browser_sync