Add initial CertVerifyProcBuiltin.

net/cert/internal/signature_policy.h

Index: net/cert/internal/signature_policy.h
diff --git a/net/cert/internal/signature_policy.h b/net/cert/internal/signature_policy.h
index 86d6c32b19f938523dfbc77f385d1235045adac8..fbc94ad976f0fa312284912a1449587709912d88 100644
--- a/net/cert/internal/signature_policy.h
+++ b/net/cert/internal/signature_policy.h
@@ -9,6 +9,7 @@
 
 #include "base/compiler_specific.h"
 #include "net/base/net_export.h"
+#include "net/cert/internal/cert_errors.h"
 #include "net/cert/internal/signature_algorithm.h"
 
 namespace net {
@@ -61,6 +62,9 @@ class NET_EXPORT SimpleSignaturePolicy : public SignaturePolicy {
   const size_t min_rsa_modulus_length_bits_;
 };
 
+// TODO(crbug.com/634443): Move exported errors to a central location?
+extern CertErrorId kRsaModulusTooSmall;
+
 }  // namespace net
 
 #endif  // NET_CERT_INTERNAL_SIGNATURE_POLICY_H_