net: Cleanup class/struct forward declarations

net/cert/x509_util.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 NET_CERT_X509_UTIL_H_
 #define NET_CERT_X509_UTIL_H_
 
 #include <stdint.h>
 
 #include <memory>
 #include <string>
 #include <vector>
 
 #include "base/memory/ref_counted.h"
 #include "base/strings/string_piece.h"
 #include "base/time/time.h"
 #include "net/base/net_export.h"
 
 namespace crypto {
-class ECPrivateKey;
 class RSAPrivateKey;
 }
 
 namespace net {
 
 class X509Certificate;
 
 namespace x509_util {
 
 // Supported digest algorithms for signing certificates.
@@ skipping 75 matching lines @@
 
  private:
   base::Time now_;
 };
 
 } // namespace x509_util
 
 } // namespace net
 
 #endif  // NET_CERT_X509_UTIL_H_