Add a fuzzer for GzipSourceStream

net/filter/gzip_source_stream_fuzzer.cc

Index: net/filter/gzip_source_stream_fuzzer.cc
diff --git a/net/filter/gzip_source_stream_fuzzer.cc b/net/filter/gzip_source_stream_fuzzer.cc
new file mode 100644
index 0000000000000000000000000000000000000000..e380ca7f0179a59ca3e2d71c93234369aa7d45d9
--- /dev/null
+++ b/net/filter/gzip_source_stream_fuzzer.cc
@@ -0,0 +1,43 @@
+// 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 "net/filter/gzip_source_stream.h"
+
+#include "base/logging.h"
+#include "base/memory/ref_counted.h"
+#include "base/test/fuzzed_data_provider.h"
+#include "net/base/io_buffer.h"
+#include "net/base/test_completion_callback.h"
+#include "net/filter/fuzzed_source_stream.h"
+
+// Fuzzer for GzipSourceStream.
+//
+// |data| is used to create a FuzzedSocket.
+extern "C" int LLVMFuzzerTestOneInput(const uint8_t* data, size_t size) {
+  net::TestCompletionCallback callback;
+  base::FuzzedDataProvider data_provider(data, size);
+  std::unique_ptr<net::FuzzedSourceStream> fuzzed_source_stream(
+      new net::FuzzedSourceStream(&data_provider));
+
+  const net::SourceStream::SourceType kGzipTypes[] = {
+      net::SourceStream::TYPE_GZIP, net::SourceStream::TYPE_DEFLATE,
+      net::SourceStream::TYPE_GZIP_FALLBACK};
+  net::SourceStream::SourceType type =
+      data_provider.PickValueInArray(kGzipTypes);
+  std::unique_ptr<net::GzipSourceStream> gzip_stream =
+      net::GzipSourceStream::Create(std::move(fuzzed_source_stream), type);
+  while (true) {
+    scoped_refptr<net::IOBufferWithSize> io_buffer(
+        new net::IOBufferWithSize(64));
+    int result = gzip_stream->Read(io_buffer.get(), io_buffer->size(),
+                                   callback.callback());
+    // Releasing the pointer to IOBuffer immediately is more likely to lead to a
+    // use-after-free.
+    io_buffer = nullptr;
+    if (callback.GetResult(result) <= 0)
+      break;
+  }
+
+  return 0;
+}