Roll HarfBuzz to 1.4.6

third_party/harfbuzz-ng/src/hb-face-private.hh

Index: third_party/harfbuzz-ng/src/hb-face-private.hh
diff --git a/third_party/harfbuzz-ng/src/hb-face-private.hh b/third_party/harfbuzz-ng/src/hb-face-private.hh
index 43e7b1cb3ff7edb99e8a3ce976c34431b539d154..eb0e850aa87a6c45dfc619962bf2c1fa620cbf84 100644
--- a/third_party/harfbuzz-ng/src/hb-face-private.hh
+++ b/third_party/harfbuzz-ng/src/hb-face-private.hh
@@ -54,6 +54,13 @@ struct hb_face_t {
   mutable unsigned int upem;		/* Units-per-EM. */
   mutable unsigned int num_glyphs;	/* Number of glyphs. */
 
+  enum dirty_t {
+    NOTHING	= 0x0000,
+    INDEX	= 0x0001,
+    UPEM	= 0x0002,
+    NUM_GLYPHS	= 0x0004,
+  } dirty;
+
   struct hb_shaper_data_t shaper_data;	/* Various shaper data. */
 
   /* Various non-shaping data. */
@@ -99,6 +106,8 @@ struct hb_face_t {
   HB_INTERNAL void load_num_glyphs (void) const;
 };
 
+HB_MARK_AS_FLAG_T (hb_face_t::dirty_t);
+
 extern HB_INTERNAL const hb_face_t _hb_face_nil;
 
 #define HB_SHAPER_DATA_CREATE_FUNC_EXTRA_ARGS