--- a/src/java.desktop/share/native/libfontmanager/harfbuzz/hb-face-private.hh	Tue Dec 05 11:04:42 2017 -0800
+++ b/src/java.desktop/share/native/libfontmanager/harfbuzz/hb-face-private.hh	Thu Dec 07 11:55:06 2017 -0800
@@ -50,12 +50,16 @@
   void                      *user_data;
   hb_destroy_func_t          destroy;
 
-  unsigned int index;
-  mutable unsigned int upem;
-  mutable unsigned int num_glyphs;
+  unsigned int index;                   /* Face index in a collection, zero-based. */
+  mutable unsigned int upem;            /* Units-per-EM. */
+  mutable unsigned int num_glyphs;      /* Number of glyphs. */
 
-  struct hb_shaper_data_t shaper_data;
+  struct hb_shaper_data_t shaper_data;  /* Various shaper data. */
 
+  /* Various non-shaping data. */
+  /* ... */
+
+  /* Cache */
   struct plan_node_t {
     hb_shape_plan_t *shape_plan;
     plan_node_t *next;