Update from https://crrev.com/316786

third_party/harfbuzz-ng/src/hb-buffer.cc

 /*
  * Copyright © 1998-2004  David Turner and Werner Lemberg
  * Copyright © 2004,2007,2009,2010  Red Hat, Inc.
  * Copyright © 2011,2012  Google, Inc.
  *
  *  This is part of HarfBuzz, a text shaping library.
  *
  * Permission is hereby granted, without written agreement and without
  * license or royalty fees, to use, copy, modify, and distribute this
  * software and its documentation for any purpose, provided that the
@@ skipping 1310 matching lines @@
  * taking buffer script into consideration when choosing a language.
  *
  * Since: 1.0
  **/
 void
 hb_buffer_guess_segment_properties (hb_buffer_t *buffer)
 {
   buffer->guess_segment_properties ();
 }
 
-template <bool validate, typename T>
+template <typename utf_t>
 static inline void
 hb_buffer_add_utf (hb_buffer_t  *buffer,
-                   const T      *text,
+                   const typename utf_t::codepoint_t *text,
                    int           text_length,
                    unsigned int  item_offset,
                    int           item_length)
 {
-  typedef hb_utf_t<T, true> utf_t;
+  typedef typename utf_t::codepoint_t T;
   const hb_codepoint_t replacement = buffer->replacement;
 
   assert (buffer->content_type == HB_BUFFER_CONTENT_TYPE_UNICODE ||
           (!buffer->len && buffer->content_type == HB_BUFFER_CONTENT_TYPE_INVALID));
 
   if (unlikely (hb_object_is_inert (buffer)))
     return;
 
   if (text_length == -1)
     text_length = utf_t::strlen (text);
@@ skipping 43 matching lines @@
     next = utf_t::next (next, end, &u, replacement);
     buffer->context[1][buffer->context_len[1]++] = u;
   }
 
   buffer->content_type = HB_BUFFER_CONTENT_TYPE_UNICODE;
 }
 
 /**
  * hb_buffer_add_utf8:
  * @buffer: a buffer.
- * @text: (array length=text_length):
+ * @text: (array length=text_length) (element-type uint8_t):
  * @text_length: 
  * @item_offset: 
  * @item_length: 
  *
  * 
  *
  * Since: 1.0
  **/
 void
 hb_buffer_add_utf8 (hb_buffer_t  *buffer,
                     const char   *text,
                     int           text_length,
                     unsigned int  item_offset,
                     int           item_length)
 {
-  hb_buffer_add_utf<true> (buffer, (const uint8_t *) text, text_length, item_offset, item_length);
+  hb_buffer_add_utf<hb_utf8_t> (buffer, (const uint8_t *) text, text_length, item_offset, item_length);
 }
 
 /**
  * hb_buffer_add_utf16:
  * @buffer: a buffer.
  * @text: (array length=text_length):
  * @text_length: 
  * @item_offset: 
  * @item_length: 
  *
  * 
  *
  * Since: 1.0
  **/
 void
 hb_buffer_add_utf16 (hb_buffer_t    *buffer,
                      const uint16_t *text,
                      int             text_length,
                      unsigned int    item_offset,
                      int             item_length)
 {
-  hb_buffer_add_utf<true> (buffer, text, text_length, item_offset, item_length);
+  hb_buffer_add_utf<hb_utf16_t> (buffer, text, text_length, item_offset, item_length);
 }
 
 /**
  * hb_buffer_add_utf32:
  * @buffer: a buffer.
  * @text: (array length=text_length):
  * @text_length: 
  * @item_offset: 
  * @item_length: 
  *
  * 
  *
  * Since: 1.0
  **/
 void
 hb_buffer_add_utf32 (hb_buffer_t    *buffer,
                      const uint32_t *text,
                      int             text_length,
                      unsigned int    item_offset,
                      int             item_length)
 {
-  hb_buffer_add_utf<true> (buffer, text, text_length, item_offset, item_length);
+  hb_buffer_add_utf<hb_utf32_t<> > (buffer, text, text_length, item_offset, item_length);
 }
 
 /**
+ * hb_buffer_add_latin1:
+ * @buffer: a buffer.
+ * @text: (array length=text_length) (element-type uint8_t):
+ * @text_length: 
+ * @item_offset: 
+ * @item_length: 
+ *
+ * 
+ *
+ * Since: 1.0
+ **/
+void
+hb_buffer_add_latin1 (hb_buffer_t   *buffer,
+                      const uint8_t *text,
+                      int            text_length,
+                      unsigned int   item_offset,
+                      int            item_length)
+{
+  hb_buffer_add_utf<hb_latin1_t> (buffer, text, text_length, item_offset, item_length);
+}
+
+/**
  * hb_buffer_add_codepoints:
  * @buffer: a buffer.
  * @text: (array length=text_length):
  * @text_length: 
  * @item_offset: 
  * @item_length: 
  *
  * 
  *
  * Since: 1.0
  **/
 void
 hb_buffer_add_codepoints (hb_buffer_t          *buffer,
                           const hb_codepoint_t *text,
                           int                   text_length,
                           unsigned int          item_offset,
                           int                   item_length)
 {
-  hb_buffer_add_utf<false> (buffer, text, text_length, item_offset, item_length);
+  hb_buffer_add_utf<hb_utf32_t<false> > (buffer, text, text_length, item_offset, item_length);
 }
 
 
 static int
 compare_info_codepoint (const hb_glyph_info_t *pa,
                         const hb_glyph_info_t *pb)
 {
   return (int) pb->codepoint - (int) pa->codepoint;
 }
 
@@ skipping 67 matching lines @@
 
   unsigned int start = 0;
   unsigned int end;
   for (end = start + 1; end < count; end++)
     if (info[start].cluster != info[end].cluster) {
       normalize_glyphs_cluster (buffer, start, end, backward);
       start = end;
     }
   normalize_glyphs_cluster (buffer, start, end, backward);
 }