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

net/base/scoped_cert_chain_context.h

-// 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.
-
-#ifndef NET_BASE_SCOPED_CERT_CHAIN_CONTEXT_H_
-#define NET_BASE_SCOPED_CERT_CHAIN_CONTEXT_H_
-#pragma once
-
-#include <windows.h>
-#include <wincrypt.h>
-
-#include "base/memory/scoped_ptr.h"
-
-namespace net {
-
-// This class wraps the CertFreeCertificateChain function in a class that can
-// be passed as a template argument to scoped_ptr_malloc.
-class ScopedPtrMallocFreeCertChain {
- public:
-  void operator()(const CERT_CHAIN_CONTEXT* x) const {
-    CertFreeCertificateChain(x);
-  }
-};
-
-typedef scoped_ptr_malloc<const CERT_CHAIN_CONTEXT,
-                          ScopedPtrMallocFreeCertChain> ScopedCertChainContext;
-
-}  // namespace net
-
-#endif  // NET_BASE_SCOPED_CERT_CHAIN_CONTEXT_H_