Add QuicFramer and friends.

net/quic/crypto/null_decrypter.h

Index: net/quic/crypto/null_decrypter.h
diff --git a/net/quic/crypto/null_decrypter.h b/net/quic/crypto/null_decrypter.h
new file mode 100644
index 0000000000000000000000000000000000000000..54950921bfa1ff1acfae6847422b977700e640a8
--- /dev/null
+++ b/net/quic/crypto/null_decrypter.h
@@ -0,0 +1,28 @@
+// Copyright (c) 2012 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 NET_QUIC_CRYPTO_NULL_DECRYPTER_H_
+#define NET_QUIC_CRYPTO_NULL_DECRYPTER_H_
+
+#include "base/compiler_specific.h"
+#include "net/base/net_export.h"
+#include "net/quic/crypto/quic_decrypter.h"
+
+namespace net {
+
+// A NullDecrypter is a QuicDecrypter used before a crypto negotiation
+// has occurred.  It does not actually decrypt the payload, but does
+// verify a hash (fnv128) over both the payload and associated data.

[Ryan Sleevi, 2012/10/17 04:27:13]

nit: comment update to explain that the hash is not for cryptographic protection
(at least AIUI, it's for error control)

+class NET_EXPORT_PRIVATE NullDecrypter : public QuicDecrypter {
+ public:
+  virtual ~NullDecrypter() {}
+
+  // QuicDecrypter implementation
+  virtual QuicData* Decrypt(base::StringPiece associated_data,
+                            base::StringPiece ciphertext) OVERRIDE;
+};
+
+}  // namespace net
+
+#endif  // NET_QUIC_CRYPTO_NULL_DECRYPTER_H_