Converts test_wm to use aura

ui/aura/mus/window_mus.h

Index: ui/aura/mus/window_mus.h
diff --git a/ui/aura/mus/window_mus.h b/ui/aura/mus/window_mus.h
index c389eb3500dea9eda45012e710c5ea6a90cf00f8..edd5a5a6552358d8e75bfd56ef55f9361b747746 100644
--- a/ui/aura/mus/window_mus.h
+++ b/ui/aura/mus/window_mus.h
@@ -81,6 +81,9 @@ class AURA_EXPORT WindowMus {
                                      const std::vector<uint8_t>* data) = 0;
   virtual void SetSurfaceIdFromServer(
       std::unique_ptr<SurfaceInfo> surface_info) = 0;
+  // The window was deleted on the server side. DestroyFromServer() should
+  // result in deleting |this|.
+  virtual void DestroyFromServer() = 0;
   virtual void AddTransientChildFromServer(WindowMus* child) = 0;
   virtual void RemoveTransientChildFromServer(WindowMus* child) = 0;
   // Called when a window was added/removed as a transient child.