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

net/cert/signed_certificate_timestamp.h

Index: net/cert/signed_certificate_timestamp.h
diff --git a/net/cert/signed_certificate_timestamp.h b/net/cert/signed_certificate_timestamp.h
index 02697dc7a1fe6ce8da113a011ba84d38d6b7e841..1714797631d44352c3573f0d6760222b620941dd 100644
--- a/net/cert/signed_certificate_timestamp.h
+++ b/net/cert/signed_certificate_timestamp.h
@@ -93,6 +93,8 @@ struct NET_EXPORT SignedCertificateTimestamp
 
   // Version enum in RFC 6962, Section 3.2.
   enum Version {
+    // TODO(robpercival): Fix inconsistent naming between this and

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

Not convinced about the value of this TODO - if it's a simple fix as suggested,
simply do it in a follow-up CL, if not, please expand the description of this
TODO to indicate what exactly you'd want to fix. 

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

Done in https://codereview.chromium.org/1951233003.

+    // SignedTreeHead::Version.
     SCT_VERSION_1 = 0,
   };