change SkClipOp to a class enum

BUG=skia:

Change-Id: I25dbe6d6b8666a2a0a7be7bdd2ae0b067868d14e
Reviewed-on: https://skia-review.googlesource.com/5718
Reviewed-by: Mike Reed <reed@google.com>
Commit-Queue: Mike Reed <reed@google.com>
diff --git a/fuzz/FuzzDrawFunctions.cpp b/fuzz/FuzzDrawFunctions.cpp
index cee866c..af4d09b 100644
--- a/fuzz/FuzzDrawFunctions.cpp
+++ b/fuzz/FuzzDrawFunctions.cpp
@@ -13,6 +13,7 @@
 #include "SkPath.h"
 #include "SkSurface.h"
 #include "SkTypeface.h"
+#include "SkClipOpPriv.h"
 
 static const int kBmpSize = 24;
 static const int kMaxX = 250;