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

chrome/browser/ui/cocoa/ssl_client_certificate_selector_cocoa.mm

 // Copyright (c) 2012 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.
 
 #import "chrome/browser/ui/cocoa/ssl_client_certificate_selector_cocoa.h"
 
 #import <SecurityInterface/SFChooseIdentityPanel.h>
 #include <stddef.h>
 
 #include <utility>
@@ skipping 190 matching lines @@
     constrainedWindow_->CloseWebContentsModalDialog();
   }
 }
 
 - (void)displayForWebContents:(content::WebContents*)webContents {
   // Create an array of CFIdentityRefs for the certificates:
   size_t numCerts = observer_->cert_request_info()->client_certs.size();
   identities_.reset(CFArrayCreateMutable(
       kCFAllocatorDefault, numCerts, &kCFTypeArrayCallBacks));
   for (size_t i = 0; i < numCerts; ++i) {
-    SecCertificateRef cert =
-        observer_->cert_request_info()->client_certs[i]->os_cert_handle();
+    base::ScopedCFTypeRef<SecCertificateRef> cert(
+        net::x509_util::CreateSecCertificateFromX509Certificate(
+            observer_->cert_request_info()->client_certs[i].get()));
+    if (!cert)
+      continue;
     SecIdentityRef identity;
     if (SecIdentityCreateWithCertificate(NULL, cert, &identity) == noErr) {
       CFArrayAppendValue(identities_, identity);
       CFRelease(identity);
       certificates_.push_back(observer_->cert_request_info()->client_certs[i]);
     }
   }
 
   // Get the message to display:
   NSString* message = l10n_util::GetNSStringF(
@@ skipping 94 matching lines @@
 }
 
 - (void)onConstrainedWindowClosed {
   observer_->StopObserving();
   panel_.reset();
   constrainedWindow_.reset();
   [self release];
 }
 
 @end