Update harfbuzz-ng to 1a5a91dc0d8bf4b72a2f22dc6300b06ad7000b79.

third_party/harfbuzz-ng/src/hb-ot-layout.h

Index: third_party/harfbuzz-ng/src/hb-ot-layout.h
diff --git a/third_party/harfbuzz-ng/src/hb-ot-layout.h b/third_party/harfbuzz-ng/src/hb-ot-layout.h
index 9619eb79fead07b9d6871758bee088f05f511b03..447e35dbfad7363491df03081cec5b9ba4d14c05 100644
--- a/third_party/harfbuzz-ng/src/hb-ot-layout.h
+++ b/third_party/harfbuzz-ng/src/hb-ot-layout.h
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2007,2008,2009  Red Hat, Inc.
+ * Copyright © 2007,2008,2009  Red Hat, Inc.
  *
  *  This is part of HarfBuzz, a text shaping library.
  *
@@ -59,12 +59,11 @@ hb_ot_layout_get_attach_points (hb_face_t      *face,
 /* Ligature caret positions */
 unsigned int
 hb_ot_layout_get_ligature_carets (hb_font_t      *font,
-				  hb_face_t      *face,
 				  hb_direction_t  direction,
 				  hb_codepoint_t  glyph,
 				  unsigned int    start_offset,
 				  unsigned int   *caret_count /* IN/OUT */,
-				  int            *caret_array /* OUT */);
+				  hb_position_t  *caret_array /* OUT */);
 
 
 /*
@@ -93,7 +92,8 @@ hb_bool_t
 hb_ot_layout_table_choose_script (hb_face_t      *face,
 				  hb_tag_t        table_tag,
 				  const hb_tag_t *script_tags,
-				  unsigned int   *script_index);
+				  unsigned int   *script_index,
+				  hb_tag_t       *chosen_script);
 
 unsigned int
 hb_ot_layout_table_get_feature_tags (hb_face_t    *face,
@@ -166,12 +166,20 @@ hb_ot_layout_feature_get_lookup_indexes (hb_face_t    *face,
 hb_bool_t
 hb_ot_layout_has_substitution (hb_face_t *face);
 
+/* Should be called before all the substitute_lookup's are done. */
+void
+hb_ot_layout_substitute_start (hb_buffer_t  *buffer);
+
 hb_bool_t
 hb_ot_layout_substitute_lookup (hb_face_t    *face,
 				hb_buffer_t  *buffer,
 				unsigned int  lookup_index,
 				hb_mask_t     mask);
 
+/* Should be called after all the substitute_lookup's are done */
+void
+hb_ot_layout_substitute_finish (hb_buffer_t  *buffer);
+
 /*
  * GPOS
  */
@@ -179,9 +187,12 @@ hb_ot_layout_substitute_lookup (hb_face_t    *face,
 hb_bool_t
 hb_ot_layout_has_positioning (hb_face_t *face);
 
+/* Should be called before all the position_lookup's are done.  Resets positions to zero. */
+void
+hb_ot_layout_position_start (hb_buffer_t  *buffer);
+
 hb_bool_t
 hb_ot_layout_position_lookup (hb_font_t    *font,
-			      hb_face_t    *face,
 			      hb_buffer_t  *buffer,
 			      unsigned int  lookup_index,
 			      hb_mask_t     mask);