Introduce the plumbing necessary to report Unrecoverable error from model safe workers.

chrome/browser/sync/glue/password_model_worker.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 "chrome/browser/sync/glue/password_model_worker.h"
 
 #include "base/callback.h"
 #include "base/memory/ref_counted.h"
 #include "base/task.h"
 #include "base/synchronization/waitable_event.h"
 #include "chrome/browser/password_manager/password_store.h"
 
 using base::WaitableEvent;
 
 namespace browser_sync {
 
 PasswordModelWorker::PasswordModelWorker(PasswordStore* password_store)
   : password_store_(password_store) {
   DCHECK(password_store);
 }
 
 PasswordModelWorker::~PasswordModelWorker() {}
 
-void PasswordModelWorker::DoWorkAndWaitUntilDone(Callback0::Type* work) {
+UnrecoverableErrorInfo PasswordModelWorker::DoWorkAndWaitUntilDone(
+    const WorkCallback& work) {
   WaitableEvent done(false, false);
+  UnrecoverableErrorInfo error_info;
   password_store_->ScheduleTask(
       NewRunnableMethod(this, &PasswordModelWorker::CallDoWorkAndSignalTask,
-                        work, &done));
+                        work, &done, &error_info));
   done.Wait();
+  return error_info;
 }
 
-void PasswordModelWorker::CallDoWorkAndSignalTask(Callback0::Type* work,
-                                                  WaitableEvent* done) {
-  work->Run();
+void PasswordModelWorker::CallDoWorkAndSignalTask(
+    const WorkCallback& work,
+    WaitableEvent* done,
+    UnrecoverableErrorInfo* error_info) {
+  *error_info = work.Run();
   done->Signal();
 }
 
 ModelSafeGroup PasswordModelWorker::GetModelSafeGroup() {
   return GROUP_PASSWORD;
 }
 
 }  // namespace browser_sync