Add dirty-state tracking to hb_face_t
diff --git a/src/hb-font.cc b/src/hb-font.cc
index cc0e6c3..a08766f 100644
--- a/src/hb-font.cc
+++ b/src/hb-font.cc
@@ -1196,7 +1196,7 @@
     NULL, /* user_data */
     NULL, /* destroy */
 
-    hb_font_t::NOTHING, /* dirty_bits */
+    hb_font_t::NOTHING, /* dirty */
 
     {
 #define HB_SHAPER_IMPLEMENT(shaper) HB_SHAPER_DATA_INVALID,