[Cleanup] Used scoped pointers in KeyedServiceFactory's SetTestingFactory functions.

chrome/browser/signin/test_signin_client_builder.h

 // Copyright 2014 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.
 
 #ifndef CHROME_BROWSER_SIGNIN_TEST_SIGNIN_CLIENT_BUILDER_H_
 #define CHROME_BROWSER_SIGNIN_TEST_SIGNIN_CLIENT_BUILDER_H_
 
+#include "base/memory/scoped_ptr.h"
+
 class KeyedService;
 
 namespace content {
 class BrowserContext;
 }
 
 namespace signin {
 
 // Method to be used by the |ChromeSigninClientFactory| to create a test version
 // of the SigninClient
-KeyedService* BuildTestSigninClient(content::BrowserContext* context);
+scoped_ptr<KeyedService> BuildTestSigninClient(
+    content::BrowserContext* context);
 
 }  // namespace signin
 
 
 #endif  // CHROME_BROWSER_SIGNIN_TEST_SIGNIN_CLIENT_BUILDER_H_