More or less implement RenderTextHarfBuzz

ui/gfx/render_text.cc

Index: ui/gfx/render_text.cc
diff --git a/ui/gfx/render_text.cc b/ui/gfx/render_text.cc
index 61bf1ac7da7e240177fadb13e5da2187034b2e5f..d46510447aa18ad478bd6703d4d5600ab617bbb5 100644
--- a/ui/gfx/render_text.cc
+++ b/ui/gfx/render_text.cc
@@ -17,6 +17,7 @@
 #include "third_party/skia/include/effects/SkGradientShader.h"
 #include "ui/gfx/canvas.h"
 #include "ui/gfx/insets.h"
+#include "ui/gfx/render_text_harfbuzz.h"
 #include "ui/gfx/skia_util.h"
 #include "ui/gfx/text_constants.h"
 #include "ui/gfx/text_elider.h"
@@ -349,6 +350,12 @@ Line::~Line() {}
 RenderText::~RenderText() {
 }
 
+RenderText* RenderText::CreateInstance() {
+  if (CommandLine::ForCurrentProcess()->HasSwitch("use-harfbuzz-rendertext"))
+    return new RenderTextHarfBuzz;
+  return CreateNativeInstance();
+}
+
 void RenderText::SetText(const base::string16& text) {
   DCHECK(!composition_range_.IsValid());
   if (text_ == text)