RenderTextMac: Cache the SkTypeface on the TextRun [reland]

ui/gfx/render_text.h

Index: ui/gfx/render_text.h
diff --git a/ui/gfx/render_text.h b/ui/gfx/render_text.h
index 6b0c489cf502a8ac6e8cea80dd83b320f8baeb66..32ad44bf5ed3433f56f8a02282c9b1eec57155db 100644
--- a/ui/gfx/render_text.h
+++ b/ui/gfx/render_text.h
@@ -62,7 +62,6 @@ class GFX_EXPORT SkiaTextRenderer {
                            bool subpixel_rendering_suppressed);
   void SetTypeface(SkTypeface* typeface);
   void SetTextSize(SkScalar size);
-  void SetFontWithStyle(const Font& font, int font_style);
   void SetForegroundColor(SkColor foreground);
   void SetShader(sk_sp<SkShader> shader);
   // Sets underline metrics to use if the text will be drawn with an underline.
@@ -187,8 +186,8 @@ struct Line {
 };
 
 // Creates an SkTypeface from a font and a |gfx::Font::FontStyle|.
-// May return NULL.
-skia::RefPtr<SkTypeface> CreateSkiaTypeface(const gfx::Font& font, int style);
+// May return null.
+sk_sp<SkTypeface> CreateSkiaTypeface(const gfx::Font& font, int style);
 
 // Applies the given FontRenderParams to a Skia |paint|.
 void ApplyRenderParams(const FontRenderParams& params,