Add test for typeface style round trip.

src/core/SkFontStyle.cpp

Index: src/core/SkFontStyle.cpp
diff --git a/src/core/SkFontStyle.cpp b/src/core/SkFontStyle.cpp
index 01628ae9d9d4ccdceb774ec31ab591f53cb7d9f6..fc50f1f73fb7ce2ad27e91cfc5af89bdeb43efb9 100644
--- a/src/core/SkFontStyle.cpp
+++ b/src/core/SkFontStyle.cpp
@@ -18,7 +18,7 @@ SkFontStyle::SkFontStyle() {
 
 SkFontStyle::SkFontStyle(int weight, int width, Slant slant) {
     fUnion.fU32 = 0;
-    fUnion.fR.fWeight = SkTPin<int>(weight, kThin_Weight, kBlack_Weight);
+    fUnion.fR.fWeight = SkTPin<int>(weight, kInvisible_Weight, kExtraBlack_Weight);
     fUnion.fR.fWidth = SkTPin<int>(width, kUltraCondensed_Width, kUltaExpanded_Width);
     fUnion.fR.fSlant = SkTPin<int>(slant, kUpright_Slant, kOblique_Slant);
 }