[gtk+] Implement backdrop for Quartz

[Matthias Clasen <matthiasc src gnome org>]

commit 6278d003b45a8cd13fba9c573dbff4be4b200bec
Author: Matthias Clasen <mclasen redhat com>
Date:   Tue Feb 28 20:45:18 2017 -0500

    Implement backdrop for Quartz
    
    We need to send window state change events to make GTK+
    pick up on focus changed for backdrop.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=779392

 gdk/quartz/GdkQuartzNSWindow.c |    2 ++
 1 files changed, 2 insertions(+), 0 deletions(-)
---
diff --git a/gdk/quartz/GdkQuartzNSWindow.c b/gdk/quartz/GdkQuartzNSWindow.c
index 94acc90..cafabf4 100644
--- a/gdk/quartz/GdkQuartzNSWindow.c
+++ b/gdk/quartz/GdkQuartzNSWindow.c
@@ -74,6 +74,7 @@
 {
   GdkWindow *window = [[self contentView] gdkWindow];
 
+  gdk_synthesize_window_state (window, 0, GDK_WINDOW_STATE_FOCUSED);
   _gdk_quartz_events_update_focus_window (window, TRUE);
 }
 
@@ -82,6 +83,7 @@
   GdkWindow *window = [[self contentView] gdkWindow];
 
   _gdk_quartz_events_update_focus_window (window, FALSE);
+  gdk_synthesize_window_state (window, GDK_WINDOW_STATE_FOCUSED, 0);
 }
 
 -(void)windowDidBecomeMain:(NSNotification *)aNotification