Convert mustash use surface references.

services/ui/ws/window_server.cc

Index: services/ui/ws/window_server.cc
diff --git a/services/ui/ws/window_server.cc b/services/ui/ws/window_server.cc
index e3da19d96ba8648de7e6b528c02776089600df95..6ea115f48bb1dfb0b6c0333d5fe9e676a02fd20f 100644
--- a/services/ui/ws/window_server.cc
+++ b/services/ui/ws/window_server.cc
@@ -781,6 +781,13 @@ void WindowServer::OnSurfaceCreated(const cc::SurfaceId& surface_id,
   window->GetOrCreateCompositorFrameSinkManager()->SetLatestSurfaceInfo(
       compositor_frame_sink_type, surface_id, frame_size);
 
+  // FrameGenerator will add an appropriate reference for the new surface.
+  DCHECK(display_manager_->GetDisplayContaining(window));
+  display_manager_->GetDisplayContaining(window)
+      ->platform_display()
+      ->GetFrameGenerator()
+      ->AddSurfaceReference(surface_id, window);
+
   // This is only used for testing to observe that a window has a
   // CompositorFrame.
   if (!window_paint_callback_.is_null())