[hmtx] Use more conventional internal API style
diff --git a/src/hb-ot-font.cc b/src/hb-ot-font.cc
index 4b7446e..283cfb6 100644
--- a/src/hb-ot-font.cc
+++ b/src/hb-ot-font.cc
@@ -315,5 +315,17 @@
 		     nullptr);
 }
 
+int
+hb_ot_get_side_bearing_var_tt (hb_font_t *font, hb_codepoint_t glyph, bool is_vertical)
+{
+  return font->face->table.glyf->get_side_bearing_var (glyph, font->coords, font->num_coords, is_vertical);
+}
+
+unsigned
+hb_ot_get_advance_var_tt (hb_font_t *font, hb_codepoint_t glyph, bool is_vertical)
+{
+  return font->face->table.glyf->get_advance_var (glyph, font->coords, font->num_coords, is_vertical);
+}
+
 
 #endif