Add Skottie fuzzer (via json input)

Bug: skia:
Change-Id: I97543b73755fca73f2ad014113ae8cd2c9227cf3
Reviewed-on: https://skia-review.googlesource.com/125820
Reviewed-by: Florin Malita <fmalita@chromium.org>
Commit-Queue: Kevin Lubick <kjlubick@google.com>
diff --git a/fuzz/oss_fuzz/FuzzSkottieJSON.cpp b/fuzz/oss_fuzz/FuzzSkottieJSON.cpp
new file mode 100644
index 0000000..e4f19cc
--- /dev/null
+++ b/fuzz/oss_fuzz/FuzzSkottieJSON.cpp
@@ -0,0 +1,35 @@
+/*
+ * Copyright 2018 Google, LLC
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#include "SkData.h"
+#include "Skottie.h"
+#include "SkStream.h"
+
+void FuzzSkottieJSON(sk_sp<SkData> bytes) {
+    // Always returns nullptr to any resource
+    class EmptyResourceProvider final : public skottie::ResourceProvider {
+    public:
+        std::unique_ptr<SkStream> openStream(const char resource[]) const override {
+            return nullptr;
+        }
+    };
+    SkMemoryStream stream(bytes);
+    EmptyResourceProvider erp;
+    auto animation = skottie::Animation::Make(&stream, erp);
+    if (!animation) {
+        return;
+    }
+    animation->animationTick(1337); // A "nothing up my sleeve" number
+}
+
+#if defined(IS_FUZZING_WITH_LIBFUZZER)
+extern "C" int LLVMFuzzerTestOneInput(const uint8_t *data, size_t size) {
+    auto bytes = SkData::MakeWithoutCopy(data, size);
+    FuzzSkottieJSON(bytes);
+    return 0;
+}
+#endif