Fix net_export.h includes.

net/quic/core/crypto/chacha20_poly1305_encrypter.h

 // Copyright 2014 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_QUIC_CRYPTO_CHACHA20_POLY1305_ENCRYPTER_H_
 #define NET_QUIC_CRYPTO_CHACHA20_POLY1305_ENCRYPTER_H_
 
 #include <stddef.h>
 
 #include "base/macros.h"
+#include "net/base/net_export.h"
 #include "net/quic/core/crypto/aead_base_encrypter.h"
 
 namespace net {
 
 // A ChaCha20Poly1305Encrypter is a QuicEncrypter that implements the
 // AEAD_CHACHA20_POLY1305 algorithm specified in
 // draft-agl-tls-chacha20poly1305-04, except that it truncates the Poly1305
 // authenticator to 12 bytes. Create an instance by calling
 // QuicEncrypter::Create(kCC12).
 //
 // It uses an authentication tag of 16 bytes (128 bits). There is no
 // fixed nonce prefix.
 class NET_EXPORT_PRIVATE ChaCha20Poly1305Encrypter : public AeadBaseEncrypter {
  public:
   enum {
     kAuthTagSize = 12,
   };
 
   ChaCha20Poly1305Encrypter();
   ~ChaCha20Poly1305Encrypter() override;
 
  private:
   DISALLOW_COPY_AND_ASSIGN(ChaCha20Poly1305Encrypter);
 };
 
 }  // namespace net
 
 #endif  // NET_QUIC_CRYPTO_CHACHA20_POLY1305_ENCRYPTER_H_