Validate MessageHeader before using

mojo/public/cpp/bindings/lib/message_header_validator.h

+// Copyright 2014 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 "mojo/public/cpp/bindings/message.h"
+
+namespace mojo {
+namespace internal {
+
+class MessageHeaderValidator : public MessageReceiver {
+ public:
+  explicit MessageHeaderValidator(MessageReceiver* next);
+
+  virtual bool Accept(Message* message) MOJO_OVERRIDE;
+  virtual bool AcceptWithResponder(Message* message, MessageReceiver* responder)
+      MOJO_OVERRIDE;
+
+ private:
+  MessageReceiver* next_;
+};
+
+}  // namespace internal
+}  // namespace mojo