Cleanup usage of scoped_ptr<> in remoting for C++11

remoting/host/win/session_desktop_environment.cc

 // Copyright (c) 2012 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 "remoting/host/win/session_desktop_environment.h"
 
 #include "base/logging.h"
 #include "base/single_thread_task_runner.h"
 #include "remoting/host/audio_capturer.h"
 #include "remoting/host/input_injector.h"
@@ skipping 48 matching lines @@
     base::WeakPtr<ClientSessionControl> client_session_control) {
   DCHECK(caller_task_runner()->BelongsToCurrentThread());
 
   scoped_ptr<SessionDesktopEnvironment> desktop_environment(
       new SessionDesktopEnvironment(caller_task_runner(),
                                     input_task_runner(),
                                     ui_task_runner(),
                                     inject_sas_));
   if (!desktop_environment->InitializeSecurity(client_session_control,
                                                curtain_enabled())) {
-    return scoped_ptr<DesktopEnvironment>();
+    return nullptr;
   }
 
-  return desktop_environment.PassAs<DesktopEnvironment>();
+  return desktop_environment.Pass();
 }
 
 }  // namespace remoting