Demonstrate external-window-mode in mus-demo

services/ui/service.cc

Index: services/ui/service.cc
diff --git a/services/ui/service.cc b/services/ui/service.cc
index 440df5eb22db31d08f120db203e8eabf86689027..d72e99932031da243645bb0652ac347772c75577 100644
--- a/services/ui/service.cc
+++ b/services/ui/service.cc
@@ -227,8 +227,11 @@ bool Service::OnConnect(const service_manager::ServiceInfo& remote_info,
   return true;
 }
 
-void Service::StartDisplayInit() {
-  platform_screen_->Init(window_server_->display_manager());
+void Service::StartDisplayInit(bool window_manager_connected) {
+  platform_screen_->Init(window_server_->display_manager(),
+                         window_manager_connected
+                             ? display::PlatformScreen::WINDOW_MODE_INTERNAL
+                             : display::PlatformScreen::WINDOW_MODE_EXTERNAL);
 }
 
 void Service::OnFirstDisplayReady() {