Refactor the client certificate code in chromeos/network/.

chromeos/network/certificate_pattern_matcher.h

-// 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.
-
-#ifndef CHROMEOS_NETWORK_CERTIFICATE_PATTERN_MATCHER_H_
-#define CHROMEOS_NETWORK_CERTIFICATE_PATTERN_MATCHER_H_
-
-#include "base/memory/ref_counted.h"
-#include "chromeos/chromeos_export.h"
-
-namespace net {
-class X509Certificate;
-}
-
-namespace chromeos {
-
-class CertificatePattern;
-
-namespace certificate_pattern {
-
-// Fetches the matching certificate that has the latest valid start date.
-// Returns a NULL refptr if there is no such match.
-CHROMEOS_EXPORT scoped_refptr<net::X509Certificate> GetCertificateMatch(
-    const CertificatePattern& pattern);
-
-}  // namespace certificate_pattern
-
-}  // namespace chromeos
-
-#endif  // CHROMEOS_NETWORK_CERTIFICATE_PATTERN_MATCHER_H_