Include hb-private.hh more consistently
Part of fixing https://github.com/behdad/harfbuzz/issues/585
diff --git a/util/helper-cairo.hh b/util/helper-cairo.hh
index 27b6eb3..50bc0af 100644
--- a/util/helper-cairo.hh
+++ b/util/helper-cairo.hh
@@ -24,13 +24,14 @@
* Google Author(s): Behdad Esfahbod
*/
+#ifndef HELPER_CAIRO_HH
+#define HELPER_CAIRO_HH
+
+#include "hb-private.hh"
#include "options.hh"
#include <cairo.h>
-#ifndef HELPER_CAIRO_HH
-#define HELPER_CAIRO_HH
-
cairo_scaled_font_t *
helper_cairo_create_scaled_font (const font_options_t *font_opts);