crypto: change ECSignatureCreator defaults to match SPDY.

net/spdy/spdy_credential_builder.cc

Index: net/spdy/spdy_credential_builder.cc
diff --git a/net/spdy/spdy_credential_builder.cc b/net/spdy/spdy_credential_builder.cc
index accd33d9e2e10bac00e9617f78b36ade98d0e937..fd07d520f4ff9dc6cc3c821762cc4911e035f14f 100644
--- a/net/spdy/spdy_credential_builder.cc
+++ b/net/spdy/spdy_credential_builder.cc
@@ -55,7 +55,7 @@ int SpdyCredentialBuilder::Build(const std::string& tls_unique,
   public_key = public_key.substr(2, public_key.length());
 
   // Convert the strings into a vector<unit8>
-  std::vector<uint8> proof_vector;
+  std::vector<uint8> der_signature;
   scoped_ptr<crypto::ECPrivateKey> private_key(
       crypto::ECPrivateKey::CreateFromEncryptedPrivateKeyInfo(
           ServerBoundCertService::kEPKIPassword,
@@ -63,11 +63,17 @@ int SpdyCredentialBuilder::Build(const std::string& tls_unique,
   scoped_ptr<crypto::ECSignatureCreator> creator(
       crypto::ECSignatureCreator::Create(private_key.get()));
   creator->Sign(reinterpret_cast<const unsigned char *>(secret.data()),
-                secret.length(), &proof_vector);
+                secret.length(), &der_signature);
+
+  std::string proof;
+  if (!creator->DecodeSignature(der_signature, &proof)) {
+    NOTREACHED();
+    return ERR_UNEXPECTED;
+  }
 
   credential->slot = slot;
   credential->certs.push_back(public_key.as_string());
-  credential->proof.assign(proof_vector.begin(), proof_vector.end());
+  credential->proof = proof;
   return OK;
 }