Adds a VerifyAuditProof method to CTLogVerifier

net/cert/merkle_audit_proof.h

Index: net/cert/merkle_audit_proof.h
diff --git a/net/cert/merkle_audit_proof.h b/net/cert/merkle_audit_proof.h
index b214891ee145ee74218f488d8d21e1965fd5c7dd..538bad2b38727ee6fb5bac9dfa768b1b15849391 100644
--- a/net/cert/merkle_audit_proof.h
+++ b/net/cert/merkle_audit_proof.h
@@ -26,12 +26,16 @@ NET_EXPORT uint64_t CalculateAuditPathLength(uint64_t leaf_index,
 struct NET_EXPORT MerkleAuditProof {
   MerkleAuditProof();

[Ryan Sleevi, 2016/08/25 18:56:24]

FUTURE CL: Should we still have this ctor? Would it make more sense to remove
it, given that we want to ensure all parameters are sanely initialized?

[Rob Percival, 2016/10/03 17:39:26]

LogDnsClient currently makes use of it, as it populates the proof incrementally.
It wouldn't be unreasonable to use the other constructor for that case though,
and just pass in zeros and an empty vector.

   MerkleAuditProof(uint64_t leaf_index,
+                   uint64_t tree_size,
                    const std::vector<std::string>& audit_path);
   ~MerkleAuditProof();
 
   // Index of the tree leaf in the log.
   uint64_t leaf_index = 0;
 
+  // Number of leaves in the log's tree.
+  uint64_t tree_size = 0;
+
   // Audit path nodes.
   std::vector<std::string> nodes;
 };