[gtk+] color chooser: Fix a problem with show-editor=TRUE

[Matthias Clasen <matthiasc src gnome org>]

commit e2e8231ca9dc52fcfe5d850555a8b0ae21577522
Author: Matthias Clasen <mclasen redhat com>
Date:   Wed Oct 26 14:28:17 2016 -0400

    color chooser: Fix a problem with show-editor=TRUE
    
    For some reason we end up allocating the colorplane widget
    before it is realized, and then never initialize the surface.
    
    Fix this by explicitly doing it on realize.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=773474

 gtk/gtkcolorplane.c |    9 +++++++++
 1 files changed, 9 insertions(+), 0 deletions(-)
---
diff --git a/gtk/gtkcolorplane.c b/gtk/gtkcolorplane.c
index 0e37406..cfb9a59 100644
--- a/gtk/gtkcolorplane.c
+++ b/gtk/gtkcolorplane.c
@@ -182,6 +182,14 @@ plane_size_allocate (GtkWidget     *widget,
 }
 
 static void
+plane_realize (GtkWidget *widget)
+{
+  GTK_WIDGET_CLASS (gtk_color_plane_parent_class)->realize (widget);
+
+  create_surface (GTK_COLOR_PLANE (widget));
+}
+
+static void
 set_cross_cursor (GtkWidget *widget,
                   gboolean   enabled)
 {
@@ -491,6 +499,7 @@ gtk_color_plane_class_init (GtkColorPlaneClass *class)
 
   widget_class->draw = plane_draw;
   widget_class->size_allocate = plane_size_allocate;
+  widget_class->realize = plane_realize;
   widget_class->key_press_event = plane_key_press;
 
   g_object_class_install_property (object_class,