add unpremul gm

Change-Id: I3126fb8b055b58e45f1bd0d913413b4d4d38f032
Reviewed-on: https://skia-review.googlesource.com/c/166740
Reviewed-by: Brian Osman <brianosman@google.com>
Commit-Queue: Mike Klein <mtklein@google.com>
diff --git a/gm/gm.h b/gm/gm.h
index 8536709..519c9df 100644
--- a/gm/gm.h
+++ b/gm/gm.h
@@ -144,4 +144,7 @@
     };
 }
 
+void MarkGMGood(SkCanvas*, SkScalar x, SkScalar y);
+void MarkGMBad (SkCanvas*, SkScalar x, SkScalar y);
+
 #endif