GtkStyleContext: Add gtk_render_extension().

gtk/gtkstylecontext.c

@@ -824,5 +824,27 @@ gtk_render_frame_gap (GtkStyleContext *context,
                                   xy0_gap, xy1_gap);
 }
 
+void
+gtk_render_extension (GtkStyleContext *context,
+                      cairo_t         *cr,
+                      gdouble          x,
+                      gdouble          y,
+                      gdouble          width,
+                      gdouble          height,
+                      GtkPositionType  gap_side)
+{
+  GtkStyleContextPrivate *priv;
+  GtkThemingEngineClass *engine_class;
+
+  g_return_if_fail (GTK_IS_STYLE_CONTEXT (context));
+  g_return_if_fail (cr != NULL);
+
+  priv = GTK_STYLE_CONTEXT_GET_PRIVATE (context);
+  engine_class = GTK_THEMING_ENGINE_GET_CLASS (priv->theming_engine);
+
+  _gtk_theming_engine_set_context (priv->theming_engine, context);
+  engine_class->render_extension (priv->theming_engine, cr, x, y, width, height, gap_side);
+}
+
 #define __GTK_STYLE_CONTEXT_C__
 #include "gtkaliasdef.c"

gtk/gtkstylecontext.h

@@ -172,6 +172,13 @@ void gtk_render_frame_gap (GtkStyleContext *context,
                            GtkPositionType  gap_side,
                            gdouble          xy0_gap,
                            gdouble          xy1_gap);
+void gtk_render_extension (GtkStyleContext *context,
+                           cairo_t         *cr,
+                           gdouble          x,
+                           gdouble          y,
+                           gdouble          width,
+                           gdouble          height,
+                           GtkPositionType  gap_side);
 
 G_END_DECLS