Propagates window type properties during aura-mus window creation

ui/views/mus/mus_client.h

Index: ui/views/mus/mus_client.h
diff --git a/ui/views/mus/mus_client.h b/ui/views/mus/mus_client.h
index 38087cd9e7815e036d03f56023832850e54a30e0..f238c81c8373ec8b6577d1196162c46ab06d562e 100644
--- a/ui/views/mus/mus_client.h
+++ b/ui/views/mus/mus_client.h
@@ -5,7 +5,11 @@
 #ifndef UI_VIEWS_MUS_MUS_CLIENT_H_
 #define UI_VIEWS_MUS_MUS_CLIENT_H_
 
+#include <stdint.h>
+
+#include <map>
 #include <string>
+#include <vector>
 
 #include "base/macros.h"
 #include "ui/aura/mus/window_tree_client_delegate.h"
@@ -70,6 +74,10 @@ class VIEWS_MUS_EXPORT MusClient
   static bool ShouldCreateDesktopNativeWidgetAura(
       const Widget::InitParams& init_params);
 
+  // Returns the properties to supply to mus when creating a window.
+  static std::map<std::string, std::vector<uint8_t>>
+  ConfigurePropertiesFromParams(const Widget::InitParams& init_params);
+
   service_manager::Connector* connector() { return connector_; }
 
   aura::WindowTreeClient* window_tree_client() {