Adds a function for encoding a Merkle tree leaf in TLS wire format.

net/cert/ct_serialization.h

Index: net/cert/ct_serialization.h
diff --git a/net/cert/ct_serialization.h b/net/cert/ct_serialization.h
index f183247469f9e217e017894b425c8af095127817..83fea050554c64518a7697bbb25433d00d04f485 100644
--- a/net/cert/ct_serialization.h
+++ b/net/cert/ct_serialization.h
@@ -10,6 +10,7 @@
 
 #include "base/strings/string_piece.h"
 #include "net/base/net_export.h"
+#include "net/cert/merkle_tree_leaf.h"

[Eran Messeri, 2016/05/05 15:59:33]

Nit: Can you get away with forward-declaring MerkleTreeLeaf? I would expect so,
given you only refer to it by const &.
You could add a TODO here to forward-declare everything possible.

[Rob Percival, 2016/05/05 17:31:43]

I can; I only didn't because nothing else was. I've created a new change that
forward-declares everything rather than adding a TODO:
https://codereview.chromium.org/1953773002.

 #include "net/cert/signed_certificate_timestamp.h"
 #include "net/cert/signed_tree_head.h"
 
@@ -35,6 +36,11 @@ NET_EXPORT_PRIVATE bool DecodeDigitallySigned(base::StringPiece* input,
 NET_EXPORT_PRIVATE bool EncodeLogEntry(const LogEntry& input,
                                        std::string* output);
 
+// Encodes the Merkle tree |leaf| into |output|.
+// These bytes can be hashed for use with inclusion proof fetching.
+// Note that the log ID is not serialized.
+NET_EXPORT bool EncodeTreeLeaf(const MerkleTreeLeaf& leaf, std::string* output);
+
 // Encodes the data signed by a Signed Certificate Timestamp (SCT) into
 // |output|. The signature included in the SCT is then verified over these
 // bytes.