Roll HarfBuzz to 1.4.6

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

Index: third_party/harfbuzz-ng/src/hb-font-private.hh
diff --git a/third_party/harfbuzz-ng/src/hb-font-private.hh b/third_party/harfbuzz-ng/src/hb-font-private.hh
index 53671d78d23a6da06c235c5a1bc0a6a8ffc06fb5..fbb16a0b72f3421ba7490adf80807c37aa26b250 100644
--- a/third_party/harfbuzz-ng/src/hb-font-private.hh
+++ b/third_party/harfbuzz-ng/src/hb-font-private.hh
@@ -116,6 +116,16 @@ struct hb_font_t {
   void              *user_data;
   hb_destroy_func_t  destroy;
 
+  enum dirty_t {
+    NOTHING	= 0x0000,
+    FACE	= 0x0001,
+    PARENT	= 0x0002,
+    FUNCS	= 0x0004,
+    SCALE	= 0x0008,
+    PPEM	= 0x0010,
+    VARIATIONS	= 0x0020,
+  } dirty;
+
   struct hb_shaper_data_t shaper_data;
 
 
@@ -543,6 +553,8 @@ struct hb_font_t {
   }
 };
 
+HB_MARK_AS_FLAG_T (hb_font_t::dirty_t);
+
 #define HB_SHAPER_DATA_CREATE_FUNC_EXTRA_ARGS
 #define HB_SHAPER_IMPLEMENT(shaper) HB_SHAPER_DATA_PROTOTYPE(shaper, font);
 #include "hb-shaper-list.hh"