[gtk/wip/chergert/quartz4u] macos: add surface helper

[Christian Hergert <chergert src gnome org>]

commit 3ca98355656bda43e1a58cb9b4735b28dd4ee4cc
Author: Christian Hergert <chergert redhat com>
Date:   Tue May 5 18:00:26 2020 -0700

    macos: add surface helper

 gdk/macos/GdkMacosBaseView.c | 6 ++++++
 gdk/macos/GdkMacosBaseView.h | 1 +
 2 files changed, 7 insertions(+)
---
diff --git a/gdk/macos/GdkMacosBaseView.c b/gdk/macos/GdkMacosBaseView.c
index 6db6602567..10720ae702 100644
--- a/gdk/macos/GdkMacosBaseView.c
+++ b/gdk/macos/GdkMacosBaseView.c
@@ -22,6 +22,7 @@
 #include "config.h"
 
 #import "GdkMacosBaseView.h"
+#import "GdkMacosWindow.h"
 
 #include "gdkinternals.h"
 
@@ -115,4 +116,9 @@
     [self updateTrackingRect];
 }
 
+-(GdkMacosSurface *)getGdkSurface
+{
+  return [(GdkMacosWindow *)[self window] getGdkSurface];
+}
+
 @end
diff --git a/gdk/macos/GdkMacosBaseView.h b/gdk/macos/GdkMacosBaseView.h
index f6dc125ac2..d17365625d 100644
--- a/gdk/macos/GdkMacosBaseView.h
+++ b/gdk/macos/GdkMacosBaseView.h
@@ -34,6 +34,7 @@
   NSRange selectedRange;
 }
 
+-(GdkMacosSurface *)getGdkSurface;
 -(void)setNeedsInvalidateShadow: (BOOL)invalidate;
 -(void)updateTrackingRect;
 -(NSTrackingRectTag)trackingRect;