Add fuzzer test for various media parsers

media/filters/h264_parser_fuzzertest.cc

+// Copyright 2016 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include <stddef.h>
+
+#include "base/numerics/safe_conversions.h"
+#include "media/filters/h264_parser.h"
+
+// Entry point for LibFuzzer.
+extern "C" int LLVMFuzzerTestOneInput(const uint8_t* data, size_t size) {
+  if (!size)
+    return 0;
+
+  media::H264Parser parser;
+  parser.SetStream(data, base::checked_cast<off_t>(size));
+
+  // Parse until the end of stream/unsupported stream/error in stream is
+  // found.
+  while (true) {

[DaleCurtis, 2016/03/07 21:40:17]

could do {} while (res = ok) and move res outside of the loop.

[jrummell, 2016/03/08 01:38:45]

I considered it, but there are 2 checks for != kOk.

+    media::H264NALU nalu;
+    media::H264Parser::Result res = parser.AdvanceToNextNALU(&nalu);
+    if (res != media::H264Parser::kOk)
+      break;
+
+    switch (nalu.nal_unit_type) {
+      case media::H264NALU::kIDRSlice:
+      case media::H264NALU::kNonIDRSlice: {
+        media::H264SliceHeader shdr;
+        res = parser.ParseSliceHeader(nalu, &shdr);
+        break;
+      }
+
+      case media::H264NALU::kSPS: {
+        int id;
+        res = parser.ParseSPS(&id);
+        break;
+      }
+
+      case media::H264NALU::kPPS: {
+        int id;
+        res = parser.ParsePPS(&id);
+        break;
+      }
+
+      case media::H264NALU::kSEIMessage: {
+        media::H264SEIMessage sei_msg;
+        res = parser.ParseSEI(&sei_msg);
+        break;
+      }
+
+      default:
+        // Skip any other NALU.
+        break;
+    }
+    if (res != media::H264Parser::kOk)
+      break;
+  }
+
+  return 0;
+}