chrome: Cleanup class/struct forward declarations

chrome/browser/ssl/ssl_client_certificate_selector.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 CHROME_BROWSER_SSL_SSL_CLIENT_CERTIFICATE_SELECTOR_H_
 #define CHROME_BROWSER_SSL_SSL_CLIENT_CERTIFICATE_SELECTOR_H_
 
 #include <memory>
 
 #include "base/callback_forward.h"
 
 namespace content {
 class ClientCertificateDelegate;
 class WebContents;
 }
 
 namespace net {
 class SSLCertRequestInfo;
-class X509Certificate;
 }
 
 namespace chrome {
 
 // Opens a constrained SSL client certificate selection dialog under |parent|,
 // offering certificates from |cert_request_info|. When the user has made a
 // selection, the dialog will report back to |delegate|. If the dialog is
 // closed with no selection, |delegate| will simply be destroyed.
 void ShowSSLClientCertificateSelector(
     content::WebContents* contents,
     net::SSLCertRequestInfo* cert_request_info,
     std::unique_ptr<content::ClientCertificateDelegate> delegate);
 
 }  // namespace chrome
 
 #endif  // CHROME_BROWSER_SSL_SSL_CLIENT_CERTIFICATE_SELECTOR_H_