[gtk/wip/ebassi/constraint-layout: 885/890] Move the Root interface to a private header

[Emmanuele Bassi <ebassi src gnome org>]

commit ba9a5546101b0322d8873293745b43282193f3ca
Author: Emmanuele Bassi <ebassi gnome org>
Date:   Tue Apr 9 14:13:37 2019 +0100

    Move the Root interface to a private header
    
    We don't expect out of tree implementations of GtkRoot, and having the
    interface structure private to the GTK code allows us to add virtual
    functions involving private types.

 gtk/gtkroot.h        | 14 --------------
 gtk/gtkrootprivate.h | 14 ++++++++++++++
 2 files changed, 14 insertions(+), 14 deletions(-)
---
diff --git a/gtk/gtkroot.h b/gtk/gtkroot.h
index c147c09ff0..08b3888d3c 100644
--- a/gtk/gtkroot.h
+++ b/gtk/gtkroot.h
@@ -34,20 +34,6 @@ G_BEGIN_DECLS
 GDK_AVAILABLE_IN_ALL
 G_DECLARE_INTERFACE (GtkRoot, gtk_root, GTK, ROOT, GtkWidget)
 
-/**
- * GtkRootIface:
- *
- * The list of functions that must be implemented for the #GtkRoot interface.
- */
-struct _GtkRootInterface
-{
-  /*< private >*/
-  GTypeInterface g_iface;
-
-  /*< public >*/
-  GdkDisplay * (* get_display)  (GtkRoot *self);
-};
-
 GDK_AVAILABLE_IN_ALL
 GdkDisplay * gtk_root_get_display (GtkRoot *self);
 
diff --git a/gtk/gtkrootprivate.h b/gtk/gtkrootprivate.h
index 3afbae712c..37e8149f33 100644
--- a/gtk/gtkrootprivate.h
+++ b/gtk/gtkrootprivate.h
@@ -5,6 +5,20 @@
 
 G_BEGIN_DECLS
 
+/**
+ * GtkRootIface:
+ *
+ * The list of functions that must be implemented for the #GtkRoot interface.
+ */
+struct _GtkRootInterface
+{
+  /*< private >*/
+  GTypeInterface g_iface;
+
+  /*< public >*/
+  GdkDisplay * (* get_display)  (GtkRoot *self);
+};
+
 enum {
   GTK_ROOT_PROP_FOCUS_WIDGET,
   GTK_ROOT_NUM_PROPERTIES