Add test for typeface style round trip.

include/core/SkTypeface.h

Index: include/core/SkTypeface.h
diff --git a/include/core/SkTypeface.h b/include/core/SkTypeface.h
index e3a311da4337eae9429185104225db62bed07ccb..bb11793be5abb07d34ed6795c98d16511fdf076d 100644
--- a/include/core/SkTypeface.h
+++ b/include/core/SkTypeface.h
@@ -346,6 +346,8 @@ protected:
 
     /** Sets the fixedPitch bit. If used, must be called in the constructor. */
     void setIsFixedPitch(bool isFixedPitch) { fIsFixedPitch = isFixedPitch; }
+    /** Sets the font style. If used, must be called in the constructor. */
+    void setFontStyle(SkFontStyle style) { fStyle = style; }
 
     friend class SkScalerContext;
     static SkTypeface* GetDefaultTypeface(Style style = SkTypeface::kNormal);