Add in Region SetPath Fuzzer

Also refactor a few things to make it easier to use oss-fuzz.

Bug: skia:
Change-Id: Ie518a6cfc7d57a347b5d09089379f986d33f8b7f
Reviewed-on: https://skia-review.googlesource.com/41740
Commit-Queue: Kevin Lubick <kjlubick@google.com>
Reviewed-by: Mike Klein <mtklein@google.com>
diff --git a/fuzz/oss_fuzz/FuzzRegionSetPath.cpp b/fuzz/oss_fuzz/FuzzRegionSetPath.cpp
new file mode 100644
index 0000000..e51a4c0
--- /dev/null
+++ b/fuzz/oss_fuzz/FuzzRegionSetPath.cpp
@@ -0,0 +1,46 @@
+/*
+ * Copyright 2018 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#include "../Fuzz.h"
+#include "../FuzzCommon.h"
+#include "SkData.h"
+#include "SkPath.h"
+#include "SkRegion.h"
+
+
+void FuzzRegionSetPath(Fuzz* fuzz) {
+    SkPath p;
+    fuzz_path(fuzz, &p, 1000);
+    SkRegion r1;
+    bool initR1;
+    fuzz->next(&initR1);
+    if (initR1) {
+        fuzz->next(&r1);
+    }
+    SkRegion r2;
+    fuzz->next(&r2);
+
+    r1.setPath(p, r2);
+
+    // Do some follow on computations to make sure region is well-formed.
+    r1.computeRegionComplexity();
+    r1.isComplex();
+    if (r1 == r2) {
+        r1.contains(0,0);
+    } else {
+        r1.contains(1,1);
+    }
+}
+
+#if defined(IS_FUZZING_WITH_LIBFUZZER)
+extern "C" int LLVMFuzzerTestOneInput(const uint8_t *data, size_t size) {
+    sk_sp<SkData> bytes(SkData::MakeWithoutCopy(data, size));
+    Fuzz fuzz(bytes);
+    FuzzRegionSetPath(&fuzz);
+    return 0;
+}
+#endif