Fix threading issues in WebDataRequestManager.

components/webdata/common/web_database_backend.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/webdata/common/web_database_backend.h"
 
 #include <algorithm>
 #include <utility>
 
 #include "base/bind.h"
@@ skipping 38 matching lines @@
   init_status_ = sql::INIT_FAILURE;
 }
 
 void WebDatabaseBackend::DBWriteTaskWrapper(
     const WebDatabaseService::WriteTask& task,
     std::unique_ptr<WebDataRequest> request) {
   if (request->IsCancelled())
     return;
 
   ExecuteWriteTask(task);
-  request_manager_->RequestCompleted(std::move(request));
+  request_manager_->RequestCompleted(std::move(request), nullptr);
 }
 
 void WebDatabaseBackend::ExecuteWriteTask(
     const WebDatabaseService::WriteTask& task) {
   LoadDatabaseIfNecessary();
   if (db_ && init_status_ == sql::INIT_OK) {
     WebDatabase::State state = task.Run(db_.get());
     if (state == WebDatabase::COMMIT_NEEDED)
       Commit();
   }
 }
 
 void WebDatabaseBackend::DBReadTaskWrapper(
     const WebDatabaseService::ReadTask& task,
     std::unique_ptr<WebDataRequest> request) {
   if (request->IsCancelled())
     return;
 
-  request->SetResult(ExecuteReadTask(task));
-  request_manager_->RequestCompleted(std::move(request));
+  std::unique_ptr<WDTypedResult> result = ExecuteReadTask(task);
+  request_manager_->RequestCompleted(std::move(request), std::move(result));
 }
 
 std::unique_ptr<WDTypedResult> WebDatabaseBackend::ExecuteReadTask(
     const WebDatabaseService::ReadTask& task) {
   LoadDatabaseIfNecessary();
   if (db_ && init_status_ == sql::INIT_OK) {
     return task.Run(db_.get());
   }
   return nullptr;
 }
@@ skipping 45 matching lines @@
     db_->GetSQLConnection()->RazeAndClose();
   }
 }
 
 void WebDatabaseBackend::Commit() {
   DCHECK(db_);
   DCHECK_EQ(sql::INIT_OK, init_status_);
   db_->CommitTransaction();
   db_->BeginTransaction();
 }