[mutter] Add meta_ui_window_is_dummy()

[Owen Taylor <otaylor src gnome org>]

commit 95d9a95b2b614f46b92fc7df4d2e1b1c0b4a901e
Author: Owen W. Taylor <otaylor fishsoup net>
Date:   Thu Sep 11 10:18:21 2014 -0400

    Add meta_ui_window_is_dummy()
    
    For reasons related to interaction between the GTK+ CSS code and the
    frame sync protocol, the dummy GtkWindow that MetaUI creates to track
    theme properties has to be mapped and have MetaWindow associated with it.
    Add a private function so that the test framework can filter this out.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=736505

 src/ui/ui.c |    8 ++++++++
 src/ui/ui.h |    2 ++
 2 files changed, 10 insertions(+), 0 deletions(-)
---
diff --git a/src/ui/ui.c b/src/ui/ui.c
index 963be7c..4381880 100644
--- a/src/ui/ui.c
+++ b/src/ui/ui.c
@@ -653,3 +653,11 @@ meta_ui_window_is_widget (MetaUI *ui,
   else
     return FALSE;
 }
+
+gboolean
+meta_ui_window_is_dummy (MetaUI *ui,
+                         Window  xwindow)
+{
+  GdkWindow *frames_window = gtk_widget_get_window (GTK_WIDGET (ui->frames));
+  return xwindow == gdk_x11_window_get_xid (frames_window);
+}
diff --git a/src/ui/ui.h b/src/ui/ui.h
index 2dfeead..6003389 100644
--- a/src/ui/ui.h
+++ b/src/ui/ui.h
@@ -116,5 +116,7 @@ gboolean meta_ui_have_a_theme      (void);
 
 gboolean meta_ui_window_is_widget (MetaUI *ui,
                                    Window  xwindow);
+gboolean meta_ui_window_is_dummy  (MetaUI *ui,
+                                   Window  xwindow);
 
 #endif