Adds function for generating MerkleTreeLeaf hash.

net/cert/merkle_tree_leaf.h

 // Copyright 2016 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_CERT_MERKLE_TREE_LEAF_H_
 #define NET_CERT_MERKLE_TREE_LEAF_H_
 
 #include <memory>
 #include <string>
 
@@ skipping 24 matching lines @@
   base::Time timestamp;
 
   // Extensions from the SCT.
   std::string extensions;
 };
 
 NET_EXPORT bool GetMerkleTreeLeaf(const X509Certificate* cert,
                                   const SignedCertificateTimestamp* sct,
                                   MerkleTreeLeaf* merkle_tree_leaf);
 
+// Sets |*out| to the hash of the Merkle |tree_leaf|, as defined in RFC6962.
+// Returns true if the hash was generated, false if an error occurred.
+NET_EXPORT bool Hash(const MerkleTreeLeaf& tree_leaf, std::string* out);
+
 }  // namespace ct
 
 }  // namespace net
 
 #endif  // NET_CERT_MERKLE_TREE_LEAF_H_