Add rlz_utils as a new build target to rlz/

rlz/lib/net_response_check.h

Index: rlz/lib/net_response_check.h
diff --git a/rlz/lib/net_response_check.h b/rlz/lib/net_response_check.h
new file mode 100644
index 0000000000000000000000000000000000000000..67d13ca910aae33f81b6637917ecf5f89df181e3
--- /dev/null
+++ b/rlz/lib/net_response_check.h
@@ -0,0 +1,27 @@
+// Copyright 2017 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.
+//
+
+#ifndef RLZ_LIB_NET_RESPONSE_CHECK_H_
+#define RLZ_LIB_NET_RESPONSE_CHECK_H_
+
+#include <string>
+#include "rlz/lib/rlz_api.h"
+
+// Checksum validation convenience call for RLZ network responses.
+namespace rlz_lib {
+// The maximum length of a ping response we will parse in bytes. If the response
+// is bigger, please break it up into separate calls.
+const size_t kMaxPingResponseLength = 0x4000;  // 16K
+
+// Checks if a ping response is valid - ie. it has a checksum line which
+// is the CRC-32 checksum of the message up to the checksum. If
+// checksum_idx is not NULL, it will get the index of the checksum, i.e. -
+// the effective end of the message.
+// Access: No restrictions.
+bool RLZ_LIB_API IsPingResponseValid(const char* response, int* checksum_idx);
+
+};  // namespace rlz_lib
+
+#endif  // RLZ_LIB_NET_RESPONSE_CHECK_H_