Adds DesktopWindowTreeHostMus

mash/screenlock/screenlock.cc

Index: mash/screenlock/screenlock.cc
diff --git a/mash/screenlock/screenlock.cc b/mash/screenlock/screenlock.cc
index 87e6802f248108311550f324967fd26b1840b8f6..a488f56969175cc87df11a472c922a1c41b9247a 100644
--- a/mash/screenlock/screenlock.cc
+++ b/mash/screenlock/screenlock.cc
@@ -6,6 +6,7 @@
 
 #include "ash/public/cpp/shell_window_ids.h"
 #include "base/macros.h"
+#include "base/memory/ptr_util.h"
 #include "base/strings/utf_string_conversions.h"
 #include "mash/session/public/interfaces/session.mojom.h"
 #include "mojo/public/cpp/bindings/binding.h"
@@ -81,8 +82,8 @@ void Screenlock::OnStart(const service_manager::ServiceInfo& info) {
   session->AddScreenlockStateListener(
       bindings_.CreateInterfacePtrAndBind(this));
 
-  aura_init_.reset(
-      new views::AuraInit(connector(), "views_mus_resources.pak"));
+  aura_init_ = base::MakeUnique<views::AuraInit>(connector(), info.identity,
+                                                 "views_mus_resources.pak");
   window_manager_connection_ =
       views::WindowManagerConnection::Create(connector(), info.identity);