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

remoting/host/win/session_desktop_environment.cc

Index: remoting/host/win/session_desktop_environment.cc
diff --git a/remoting/host/win/session_desktop_environment.cc b/remoting/host/win/session_desktop_environment.cc
index 82951ea90aa4b4f8a0c3502730da8fe6186f91e0..3336482f69f3c99d28b73f82806dc3e95555a99e 100644
--- a/remoting/host/win/session_desktop_environment.cc
+++ b/remoting/host/win/session_desktop_environment.cc
@@ -66,10 +66,10 @@ scoped_ptr<DesktopEnvironment> SessionDesktopEnvironmentFactory::Create(
                                     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