Pref service: add a factory to create the client lib

services/service_manager/public/cpp/lib/service_test.cc

 // Copyright 2016 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 "services/service_manager/public/cpp/service_test.h"
 
 #include "base/memory/ptr_util.h"
 #include "base/message_loop/message_loop.h"
 #include "base/run_loop.h"
 #include "base/threading/thread.h"
@@ skipping 71 matching lines @@
   context_ = base::MakeUnique<ServiceContext>(CreateService(),
                                               mojom::ServiceRequest(&service));
   background_service_manager_->RegisterService(
       Identity(test_name_, mojom::kRootUserID), std::move(service), nullptr);
   connector_ = context_->connector();
   run_loop.Run();
 }
 
 void ServiceTest::TearDown() {
   background_service_manager_.reset();
+  context_.reset();
   message_loop_.reset();
-  context_.reset();
 }
 
 }  // namespace test
 }  // namespace service_manager