[metacity] window: add meta_window_get_toplevel_xwindow

[Alberts Muktupāvels <muktupavels src gnome org>]

commit 89f40492376b10fad9a5c9a338707f936b6e4785
Author: Alberts Muktupāvels <alberts muktupavels gmail com>
Date:   Wed Sep 11 23:51:48 2019 +0300

    window: add meta_window_get_toplevel_xwindow

 src/core/window.c    | 9 +++++++++
 src/include/window.h | 1 +
 2 files changed, 10 insertions(+)
---
diff --git a/src/core/window.c b/src/core/window.c
index 50118752..bdb2512e 100644
--- a/src/core/window.c
+++ b/src/core/window.c
@@ -8963,6 +8963,15 @@ meta_window_get_xwindow (MetaWindow *window)
   return window->xwindow;
 }
 
+Window
+meta_window_get_toplevel_xwindow (MetaWindow *window)
+{
+  if (window->frame != NULL)
+    return meta_frame_get_xwindow (window->frame);
+
+  return window->xwindow;
+}
+
 /**
  * meta_window_get_transient_for:
  * @window: a #MetaWindow
diff --git a/src/include/window.h b/src/include/window.h
index 66d5822c..c8e4c317 100644
--- a/src/include/window.h
+++ b/src/include/window.h
@@ -38,6 +38,7 @@ gboolean meta_window_is_shaded (MetaWindow *window);
 MetaScreen *meta_window_get_screen (MetaWindow *window);
 MetaDisplay *meta_window_get_display (MetaWindow *window);
 Window meta_window_get_xwindow (MetaWindow *window);
+Window meta_window_get_toplevel_xwindow (MetaWindow *window);
 MetaWindow *meta_window_get_transient_for (MetaWindow *window);
 gboolean meta_window_is_fullscreen (MetaWindow *window);
 gboolean meta_window_is_maximized (MetaWindow *window);