Move more internal fuzzers to public.

Change-Id: Idde75f374264666e4c54a17b1606464ad5d00d9c

tests/fuzzer/dec_fuzzer.cc

@@ -0,0 +1,48 @@
+// Copyright 2024 Google Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+////////////////////////////////////////////////////////////////////////////////
+
+#include <cstdint>
+#include <cstdio>
+#include <string_view>
+
+#include "src/webp/decode.h"
+#include "tests/fuzzer/fuzz_utils.h"
+
+namespace {
+
+void DecodeWebP(std::string_view arbitrary_bytes) {
+  WebPDecoderConfig decoder_config;
+  if (!WebPInitDecoderConfig(&decoder_config)) {
+    fprintf(stderr, "WebPInitDecoderConfig failed.\n");
+    abort();
+  }
+  const VP8StatusCode status =
+      WebPDecode(reinterpret_cast<const uint8_t*>(arbitrary_bytes.data()),
+                 arbitrary_bytes.size(), &decoder_config);
+  WebPFreeDecBuffer(&decoder_config.output);
+  // The decoding may fail (because the fuzzed input can be anything) but not
+  // for these reasons.
+  if (status == VP8_STATUS_SUSPENDED || status == VP8_STATUS_USER_ABORT) {
+    abort();
+  }
+}
+
+FUZZ_TEST(WebPSuite, DecodeWebP)
+    .WithDomains(
+        fuzztest::String()
+            .WithMaxSize(fuzz_utils::kMaxWebPFileSize + 1));
+
+}  // namespace