Ensure X509Certificate::OSCertHandles are safe to be used on both UI and IO threads on Win

chrome/browser/ui/views/certificate_viewer_win.cc

-// Copyright (c) 2010 The Chromium Authors. All rights reserved.
+// Copyright (c) 2011 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.
 
 #include "chrome/browser/certificate_viewer.h"
 
 #include <windows.h>
 #include <cryptuiapi.h>
 #pragma comment(lib, "cryptui.lib")
 
+#include "base/logging.h"
 #include "net/base/x509_certificate.h"
 
 void ShowCertificateViewer(gfx::NativeWindow parent,
                            net::X509Certificate* cert) {
+  // Create a new cert context and store containing just the certificate
+  // and its intermediate certificates.
+  PCCERT_CONTEXT cert_list = cert->CreateOSCertChainForCert();
+  CHECK(cert_list);
+
   CRYPTUI_VIEWCERTIFICATE_STRUCT view_info = { 0 };
   view_info.dwSize = sizeof(view_info);
   // We set our parent to the tab window. This makes the cert dialog created
   // in CryptUIDlgViewCertificate modal to the browser.
   view_info.hwndParent = parent;
   view_info.dwFlags = CRYPTUI_DISABLE_EDITPROPERTIES |
                       CRYPTUI_DISABLE_ADDTOSTORE;
-  view_info.pCertContext = cert->os_cert_handle();
-  // Search the cert store that 'cert' is in when building the cert chain.
-  HCERTSTORE cert_store = view_info.pCertContext->hCertStore;
+  view_info.pCertContext = cert_list;
+  HCERTSTORE cert_store = cert_list->hCertStore;
   view_info.cStores = 1;
   view_info.rghStores = &cert_store;
   BOOL properties_changed;
 
   // This next call blocks but keeps processing windows messages, making it
   // modal to the browser window.
   BOOL rv = ::CryptUIDlgViewCertificate(&view_info, &properties_changed);
+
+  CertFreeCertificateContext(cert_list);
 }