gdk: Remove gdk_cairo_surface_create_from_pixbuf()

It's unused and people should use textures and snapshots anyway.

docs/reference/gdk/gdk4-sections.txt

@@ -415,7 +415,6 @@ gdk_cairo_set_source_pixbuf
 gdk_cairo_rectangle
 gdk_cairo_region
 gdk_cairo_region_create_from_surface
-gdk_cairo_surface_create_from_pixbuf
 gdk_cairo_draw_from_gl
 gdk_cairo_surface_upload_to_gl
 </SECTION>

gdk/gdkcairo.c

@@ -237,46 +237,6 @@ gdk_cairo_surface_paint_pixbuf (cairo_surface_t *surface,
   cairo_surface_mark_dirty (surface);
 }
 
-/**
- * gdk_cairo_surface_create_from_pixbuf:
- * @pixbuf: a #GdkPixbuf
- * @scale: the scale of the new surface, or 0 to use same as @surface
- * @for_surface: (allow-none): The surface this will be drawn to, or %NULL
- *
- * Creates an image surface with the same contents as
- * the pixbuf.
- *
- * Returns: a new cairo surface, must be freed with cairo_surface_destroy()
- */
-cairo_surface_t *
-gdk_cairo_surface_create_from_pixbuf (const GdkPixbuf *pixbuf,
-                                      int              scale,
-                                      GdkSurface       *for_surface)
-{
-  cairo_format_t format;
-  cairo_surface_t *surface;
-
-  g_return_val_if_fail (GDK_IS_PIXBUF (pixbuf), NULL);
-  g_return_val_if_fail (scale >= 0, NULL);
-  g_return_val_if_fail (for_surface == NULL || GDK_IS_SURFACE (for_surface), NULL);
-
-  if (gdk_pixbuf_get_n_channels (pixbuf) == 3)
-    format = CAIRO_FORMAT_RGB24;
-  else
-    format = CAIRO_FORMAT_ARGB32;
-
-  surface =
-     gdk_surface_create_similar_image_surface (for_surface,
-					      format,
-                                              gdk_pixbuf_get_width (pixbuf),
-                                              gdk_pixbuf_get_height (pixbuf),
-					      scale);
-
-  gdk_cairo_surface_paint_pixbuf (surface, pixbuf);
-
-  return surface;
-}
-
 /**
  * gdk_cairo_set_source_pixbuf:
  * @cr: a cairo context

gdk/gdkcairo.h

@@ -56,10 +56,6 @@ cairo_region_t *
                                         (cairo_surface_t      *surface);
 
 GDK_AVAILABLE_IN_ALL
-cairo_surface_t * gdk_cairo_surface_create_from_pixbuf      (const GdkPixbuf *pixbuf,
-                                                             int scale,
-                                                             GdkSurface *for_surface);
-GDK_AVAILABLE_IN_ALL
 void       gdk_cairo_draw_from_gl (cairo_t              *cr,
                                    GdkSurface            *surface,
                                    int                   source,