$OpenBSD: patch-ui_compositor_compositor_observer_h,v 1.3 2021/04/01 10:24:46 robert Exp $

Index: ui/compositor/compositor_observer.h
--- ui/compositor/compositor_observer.h.orig
+++ ui/compositor/compositor_observer.h
@@ -43,7 +43,7 @@ class COMPOSITOR_EXPORT CompositorObserver {
   // Called when a child of the compositor is resizing.
   virtual void OnCompositingChildResizing(Compositor* compositor) {}
 
-#if defined(OS_LINUX) && !defined(OS_CHROMEOS)
+#if (defined(OS_LINUX) && !defined(OS_CHROMEOS)) || defined(OS_BSD)
   // Called when a swap with new size is completed.
   virtual void OnCompositingCompleteSwapWithNewSize(ui::Compositor* compositor,
                                                     const gfx::Size& size) {}
