Make CertificateProviderService vend ClientCertIdentities directly.

chrome/browser/chromeos/certificate_provider/certificate_provider.h

 // Copyright 2015 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 CHROME_BROWSER_CHROMEOS_CERTIFICATE_PROVIDER_CERTIFICATE_PROVIDER_H_
 #define CHROME_BROWSER_CHROMEOS_CERTIFICATE_PROVIDER_CERTIFICATE_PROVIDER_H_
 
 #include <vector>
 
 #include "base/macros.h"
-#include "base/memory/ref_counted.h"
-#include "net/cert/x509_certificate.h"
+#include "net/ssl/client_cert_identity.h"
 
 namespace chromeos {
 
 class CertificateProvider {
  public:
   CertificateProvider() {}
   virtual ~CertificateProvider() {}
 
   virtual void GetCertificates(
-      const base::Callback<void(const net::CertificateList&)>& callback) = 0;
+      const base::Callback<void(net::ClientCertIdentityList)>& callback) = 0;
 
   virtual std::unique_ptr<CertificateProvider> Copy() = 0;
 
  private:
   DISALLOW_COPY_AND_ASSIGN(CertificateProvider);
 };
 
 }  // namespace chromeos
 
 #endif  // CHROME_BROWSER_CHROMEOS_CERTIFICATE_PROVIDER_CERTIFICATE_PROVIDER_H_