Use CTFontCreateForString for RenderTextHarfbuzz on Mac

ui/gfx/render_text_harfbuzz.cc

Index: ui/gfx/render_text_harfbuzz.cc
diff --git a/ui/gfx/render_text_harfbuzz.cc b/ui/gfx/render_text_harfbuzz.cc
index fe492c69f1600ce59f5cab612018ef778e7541f8..6541a6a4c9991386a7a46c85af3428d6ed355177 100644
--- a/ui/gfx/render_text_harfbuzz.cc
+++ b/ui/gfx/render_text_harfbuzz.cc
@@ -36,10 +36,6 @@
 #include "ui/gfx/text_utils.h"
 #include "ui/gfx/utf16_indexing.h"
 
-#if defined(OS_WIN)
-#include "ui/gfx/font_fallback_win.h"
-#endif
-
 namespace gfx {
 
 namespace {
@@ -1508,25 +1504,28 @@ void RenderTextHarfBuzz::ShapeRun(const base::string16& text,
       return;
   }
 
-#if defined(OS_WIN)
+#if defined(OS_WIN) || defined(OS_MACOSX)
   Font fallback_font(primary_font);
-  std::string fallback_family;
+  std::string preferred_fallback_family;
   const base::char16* run_text = &(text[run->range.start()]);
   if (GetFallbackFont(primary_font, run_text, run->range.length(),
                       &fallback_font)) {
-    fallback_family = fallback_font.GetFontName();
+    preferred_fallback_family = fallback_font.GetFontName();
     if (CompareFamily(text, fallback_font, fallback_font.GetFontRenderParams(),
                       run, &best_font, &best_render_params,
                       &best_missing_glyphs))
       return;
   }
+

[Alexei Svitkine (slow), 2017/06/20 14:59:34]

Nit: Remove empty line.

[tapted, 2017/06/20 23:52:57]

Done.

 #endif
 
   std::vector<Font> fallback_font_list = GetFallbackFonts(primary_font);
 
 #if defined(OS_WIN)
-  // Append fonts in the fallback list of the fallback font.
-  if (!fallback_family.empty()) {
+  // Append fonts in the fallback list of the preferred fallback font.
+  // TODO(tapted): Investigate whether there's a case that benefits from this on
+  // Mac.
+  if (!preferred_fallback_family.empty()) {
     std::vector<Font> fallback_fonts = GetFallbackFonts(fallback_font);
     fallback_font_list.insert(fallback_font_list.end(), fallback_fonts.begin(),
                               fallback_fonts.end());
@@ -1538,7 +1537,7 @@ void RenderTextHarfBuzz::ShapeRun(const base::string16& text,
   // could be a raster font like System, which would not give us a reasonable
   // fallback font list.
   if (!base::LowerCaseEqualsASCII(primary_font.GetFontName(), "segoe ui") &&
-      !base::LowerCaseEqualsASCII(fallback_family, "segoe ui")) {
+      !base::LowerCaseEqualsASCII(preferred_fallback_family, "segoe ui")) {
     std::vector<Font> default_fallback_families =
         GetFallbackFonts(Font("Segoe UI", 13));
     fallback_font_list.insert(fallback_font_list.end(),
@@ -1555,8 +1554,8 @@ void RenderTextHarfBuzz::ShapeRun(const base::string16& text,
 
     if (font_name == primary_font.GetFontName())
       continue;
-#if defined(OS_WIN)
-    if (font_name == fallback_family)
+#if defined(OS_WIN) || defined(OS_MACOSX)

[Alexei Svitkine (slow), 2017/06/20 14:59:34]

Nit: Suggest moving preferred_fallback_family outside the ifdefs above and then
these ifdefs can be removed.

(Because preferred_fallback_family will be empty for other platforms and then no
need to ifdef here.)

[tapted, 2017/06/20 23:52:57]

Nice - Done. Collapsed the 3 `if`.

+    if (font_name == preferred_fallback_family)
       continue;
 #endif
     if (fallback_fonts.find(font) != fallback_fonts.end())