Demonstrate external-window-mode in mus-demo

services/ui/display/platform_screen_ozone.cc

Index: services/ui/display/platform_screen_ozone.cc
diff --git a/services/ui/display/platform_screen_ozone.cc b/services/ui/display/platform_screen_ozone.cc
index 3a9433d18359257a14f0e81140c148a1920dd9c7..0fec85f0760bca1d6514251d580632074d5e70dd 100644
--- a/services/ui/display/platform_screen_ozone.cc
+++ b/services/ui/display/platform_screen_ozone.cc
@@ -68,7 +68,8 @@ void PlatformScreenOzone::AddInterfaces(
   registry->AddInterface<mojom::TestDisplayController>(this);
 }
 
-void PlatformScreenOzone::Init(PlatformScreenDelegate* delegate) {
+void PlatformScreenOzone::Init(PlatformScreenDelegate* delegate,
+                               WindowMode window_mode) {
   DCHECK(delegate);
   delegate_ = delegate;
 
@@ -82,13 +83,16 @@ void PlatformScreenOzone::Init(PlatformScreenDelegate* delegate) {
         native_display_delegate->GetFakeDisplayController();
   }
 
-  // We want display configuration to happen even off device to keep the control
-  // flow similar.
-  display_configurator_.set_configure_display(true);
-  display_configurator_.AddObserver(this);
-  display_configurator_.set_state_controller(this);
-  display_configurator_.Init(std::move(native_display_delegate), false);
-  display_configurator_.ForceInitialConfigure(kChromeOsBootColor);
+  if (window_mode == WINDOW_MODE_INTERNAL) {
+    // We want display configuration to happen even off device to keep the
+    // control
+    // flow similar.
+    display_configurator_.set_configure_display(true);
+    display_configurator_.AddObserver(this);
+    display_configurator_.set_state_controller(this);
+    display_configurator_.Init(std::move(native_display_delegate), false);
+    display_configurator_.ForceInitialConfigure(kChromeOsBootColor);
+  }
 }
 
 void PlatformScreenOzone::RequestCloseDisplay(int64_t display_id) {