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

remoting/host/me2me_desktop_environment.cc

Index: remoting/host/me2me_desktop_environment.cc
diff --git a/remoting/host/me2me_desktop_environment.cc b/remoting/host/me2me_desktop_environment.cc
index e6f5fdca93de8465c7fd6840f4d53d3bbe4febdf..de92383c83c06bc77b8940763741fb2472748395 100644
--- a/remoting/host/me2me_desktop_environment.cc
+++ b/remoting/host/me2me_desktop_environment.cc
@@ -65,7 +65,7 @@ scoped_ptr<GnubbyAuthHandler> Me2MeDesktopEnvironment::CreateGnubbyAuthHandler(
         GnubbyAuthHandler::Create(client_stub));
 
   HOST_LOG << "gnubby auth is not enabled";
-  return scoped_ptr<GnubbyAuthHandler>();
+  return nullptr;
 }
 
 bool Me2MeDesktopEnvironment::InitializeSecurity(
@@ -148,11 +148,11 @@ scoped_ptr<DesktopEnvironment> Me2MeDesktopEnvironmentFactory::Create(
                                   ui_task_runner()));
   if (!desktop_environment->InitializeSecurity(client_session_control,
                                                curtain_enabled_)) {
-    return scoped_ptr<DesktopEnvironment>();
+    return nullptr;
   }
   desktop_environment->SetEnableGnubbyAuth(gnubby_auth_enabled_);
 
-  return desktop_environment.PassAs<DesktopEnvironment>();
+  return desktop_environment.Pass();
 }
 
 void Me2MeDesktopEnvironmentFactory::SetEnableCurtaining(bool enable) {