Certificate Transparency: Parse Signed Tree Heads and validate them

net/cert/signed_certificate_timestamp.cc

Index: net/cert/signed_certificate_timestamp.cc
diff --git a/net/cert/signed_certificate_timestamp.cc b/net/cert/signed_certificate_timestamp.cc
index 0a72cd1f9d2d0e55c40800284e564e30837c1385..371eea67b30dcb4ea05771b11f4fcb4620bff428 100644
--- a/net/cert/signed_certificate_timestamp.cc
+++ b/net/cert/signed_certificate_timestamp.cc
@@ -89,6 +89,12 @@ DigitallySigned::DigitallySigned() {}
 
 DigitallySigned::~DigitallySigned() {}
 
+bool DigitallySigned::SignatureParametersMatch(
+    HashAlgorithm other_hash_algorithm,
+    SignatureAlgorithm other_signature_algorithm) const {
+  return (hash_algorithm == other_hash_algorithm) &&
+         (signature_algorithm == other_signature_algorithm);
+}
 }  // namespace ct
 
 }  // namespace net