Add RetainedRef uses where needed.

components/autofill/core/browser/webdata/autofill_webdata_service.cc

 // Copyright 2013 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 "components/autofill/core/browser/webdata/autofill_webdata_service.h"
 
 #include "base/bind.h"
 #include "base/location.h"
 #include "base/logging.h"
 #include "base/single_thread_task_runner.h"
@@ skipping 256 matching lines @@
   ui_observer_list_.RemoveObserver(observer);
 }
 
 base::SupportsUserData* AutofillWebDataService::GetDBUserData() {
   DCHECK(db_thread_->BelongsToCurrentThread());
   return autofill_backend_->GetDBUserData();
 }
 
 void AutofillWebDataService::GetAutofillBackend(
     const base::Callback<void(AutofillWebDataBackend*)>& callback) {
-  db_thread_->PostTask(FROM_HERE, base::Bind(callback, autofill_backend_));
+  db_thread_->PostTask(
+      FROM_HERE, base::Bind(callback, base::RetainedRef(autofill_backend_)));
 }
 
 AutofillWebDataService::~AutofillWebDataService() {
 }
 
 void AutofillWebDataService::NotifyAutofillMultipleChangedOnUIThread() {
   DCHECK(ui_thread_->BelongsToCurrentThread());
   FOR_EACH_OBSERVER(AutofillWebDataServiceObserverOnUIThread,
                     ui_observer_list_,
                     AutofillMultipleChanged());
 }
 
 }  // namespace autofill