Add X509CertificateBytes which uses CRYPTO_BUFFER instead of macOS-native certificate types.

net/cert/x509_util_ios.h

Index: net/cert/x509_util_ios.h
diff --git a/net/cert/x509_util_ios.h b/net/cert/x509_util_ios.h
new file mode 100644
index 0000000000000000000000000000000000000000..bf3473ffcab247aec098a78b67a7e7ccb0864495
--- /dev/null
+++ b/net/cert/x509_util_ios.h
@@ -0,0 +1,27 @@
+// Copyright 2017 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_X509_UTIL_IOS_H_
+#define NET_CERT_X509_UTIL_IOS_H_
+
+#include <Security/Security.h>
+
+#include "base/mac/scoped_cftyperef.h"
+#include "net/base/net_export.h"
+
+namespace net {
+
+class X509Certificate;
+
+namespace x509_util {
+
+// Returns a SecCertificate representing |cert|, or NULL on failure.
+NET_EXPORT base::ScopedCFTypeRef<SecCertificateRef>
+CreateSecCertificateFromX509Certificate(const X509Certificate* cert);
+
+}  // namespace x509_util
+
+}  // namespace net
+
+#endif  // NET_CERT_X509_UTIL_IOS_H_