Fix RenderTextHarfBuzz glyph offset regression.

ui/gfx/render_text_harfbuzz.cc

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "ui/gfx/render_text_harfbuzz.h"
 
 #include <map>
 
 #include "base/debug/leak_annotations.h"
 #include "base/i18n/bidi_line_iterator.h"
@@ skipping 993 matching lines @@
 
   // Create a HarfBuzz buffer and add the string to be shaped. The HarfBuzz
   // buffer holds our text, run information to be used by the shaping engine,
   // and the resulting glyph data.
   hb_buffer_t* buffer = hb_buffer_create();
   hb_buffer_add_utf16(buffer, reinterpret_cast<const uint16*>(text.c_str()),
                       text.length(), run->range.start(), run->range.length());
   hb_buffer_set_script(buffer, ICUScriptToHBScript(run->script));
   hb_buffer_set_direction(buffer,
       run->is_rtl ? HB_DIRECTION_RTL : HB_DIRECTION_LTR);
   // TODO(ckocagil): Should we call |hb_buffer_set_language()| here?

[ckocagil, 2014/07/19 23:35:21]

Can you change this comment to the following 2 lines?

// TODO(ckocagil): Should we determine the actual language?
hb_buffer_set_language(buffer, hb_language_get_default());

[msw, 2014/07/20 00:08:20]

Done.

 
   // Shape the text.
   hb_shape(harfbuzz_font, buffer, NULL, 0);
 
   // Populate the run fields with the resulting glyph data in the buffer.
   unsigned int glyph_count = 0;
   hb_glyph_info_t* infos = hb_buffer_get_glyph_infos(buffer, &glyph_count);
   run->glyph_count = glyph_count;
   hb_glyph_position_t* hb_positions =
       hb_buffer_get_glyph_positions(buffer, NULL);
   run->glyphs.reset(new uint16[run->glyph_count]);
   run->glyph_to_char.reset(new uint32[run->glyph_count]);
   run->positions.reset(new SkPoint[run->glyph_count]);
   run->width = 0;
   for (size_t i = 0; i < run->glyph_count; ++i) {
     run->glyphs[i] = infos[i].codepoint;
     run->glyph_to_char[i] = infos[i].cluster;
     const int x_offset =
         SkScalarRoundToInt(SkFixedToScalar(hb_positions[i].x_offset));
     const int y_offset =
         SkScalarRoundToInt(SkFixedToScalar(hb_positions[i].y_offset));
-    run->positions[i].set(run->width + x_offset, y_offset);
+    run->positions[i].set(run->width + x_offset, -y_offset);
     run->width +=
         SkScalarRoundToInt(SkFixedToScalar(hb_positions[i].x_advance));
   }
 
   hb_buffer_destroy(buffer);
   hb_font_destroy(harfbuzz_font);
 }
 
 }  // namespace gfx