Make use of CreateInterfacePtrAndBind() where appropriate

chrome/browser/chromeos/arc/arc_auth_service.cc

 // Copyright 2015 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/chromeos/arc/arc_auth_service.h"
 
 #include <utility>
 
 namespace arc {
 
 ArcAuthService::ArcAuthService(ArcBridgeService* bridge_service)
     : ArcService(bridge_service), binding_(this) {
   arc_bridge_service()->AddObserver(this);
 }
 
 ArcAuthService::~ArcAuthService() {
   arc_bridge_service()->RemoveObserver(this);
 }
 
 void ArcAuthService::OnAuthInstanceReady() {
-  arc::AuthHostPtr host;
-  binding_.Bind(GetProxy(&host));
-  arc_bridge_service()->auth_instance()->Init(std::move(host));
+  arc_bridge_service()->auth_instance()->Init(
+      binding_.CreateInterfacePtrAndBind());
 }
 
 void ArcAuthService::GetAuthCode(const GetAuthCodeCallback& callback) {
   // TODO(victorhsieh): request auth code from LSO (crbug.com/571146).
   callback.Run(mojo::String("fake auth code from ArcAuthService in Chrome"));
 }
 
 }  // namespace arc