[gtk+/gtk-2-24] quartz: introduce gdk_quartz_window_is_quartz function

[Kristian Rietveld <kristian src gnome org>]

commit 6b8e20a05cde19500c0fb97576cc22c3ef1088dc
Author: Kristian Rietveld <kris loopnest org>
Date:   Mon Jul 18 21:59:28 2016 +0200

    quartz: introduce gdk_quartz_window_is_quartz function
    
    This function can be used to check whether a GdkWindow is a quartz
    window. It is equivalent to it's win32 counterpart. The function
    is necessary because the macro necessary for this check is private.

 gdk/quartz/gdkquartz.h        |    1 +
 gdk/quartz/gdkwindow-quartz.c |    6 ++++++
 2 files changed, 7 insertions(+), 0 deletions(-)
---
diff --git a/gdk/quartz/gdkquartz.h b/gdk/quartz/gdkquartz.h
index 3c42983..70155c0 100644
--- a/gdk/quartz/gdkquartz.h
+++ b/gdk/quartz/gdkquartz.h
@@ -52,6 +52,7 @@ typedef enum
   GDK_OSX_NEW = 99
 } GdkOSXVersion;
 
+gboolean  gdk_quartz_window_is_quartz                           (GdkWindow      *window);
 NSWindow *gdk_quartz_window_get_nswindow                        (GdkWindow      *window);
 NSView   *gdk_quartz_window_get_nsview                          (GdkWindow      *window);
 NSImage  *gdk_quartz_pixbuf_to_ns_image_libgtk_only             (GdkPixbuf      *pixbuf);
diff --git a/gdk/quartz/gdkwindow-quartz.c b/gdk/quartz/gdkwindow-quartz.c
index a7ee444..90aaa19 100644
--- a/gdk/quartz/gdkwindow-quartz.c
+++ b/gdk/quartz/gdkwindow-quartz.c
@@ -57,6 +57,12 @@ static FullscreenSavedGeometry *get_fullscreen_geometry (GdkWindow *window);
 
 static void gdk_window_impl_iface_init (GdkWindowImplIface *iface);
 
+gboolean
+gdk_quartz_window_is_quartz (GdkWindow *window)
+{
+  return GDK_WINDOW_IS_QUARTZ (window);
+}
+
 NSView *
 gdk_quartz_window_get_nsview (GdkWindow *window)
 {