FuzzDrawFunctions from twsmith

BUG=skia:

GOLD_TRYBOT_URL= https://gold.skia.org/search?issue=4979

Change-Id: Ib5cc6ea036538b611d6959c679a276050e145f57
Reviewed-on: https://skia-review.googlesource.com/4979
Reviewed-by: Mike Klein <mtklein@chromium.org>
diff --git a/BUILD.gn b/BUILD.gn
index 501c568..a5b4d37 100644
--- a/BUILD.gn
+++ b/BUILD.gn
@@ -1233,6 +1233,7 @@
   executable("fuzz") {
     sources = [
       "fuzz/FilterFuzz.cpp",
+      "fuzz/FuzzDrawFunctions.cpp",
       "fuzz/FuzzGradients.cpp",
       "fuzz/FuzzParsePath.cpp",
       "fuzz/FuzzPathop.cpp",