net: Update the include paths of base/string_piece.h to its new location.

net/quic/crypto/curve25519_key_exchange.h

 // Copyright (c) 2013 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_CURVE25519_KEY_EXCHANGE_H_
 #define NET_QUIC_CRYPTO_CURVE25519_KEY_EXCHANGE_H_
 
 #include <string>
 
 #include "base/compiler_specific.h"
-#include "base/string_piece.h"
+#include "base/strings/string_piece.h"
 #include "net/base/net_export.h"
 #include "net/quic/crypto/key_exchange.h"
 
 namespace net {
 
 class QuicRandom;
 
 // Curve25519KeyExchange implements a KeyExchange using elliptic-curve
 // Diffie-Hellman on curve25519. See http://cr.yp.to/ecdh.html
 class NET_EXPORT_PRIVATE Curve25519KeyExchange : public KeyExchange {
@@ skipping 17 matching lines @@
  private:
   Curve25519KeyExchange();
 
   uint8 private_key_[32];
   uint8 public_key_[32];
 };
 
 }  // namespace net
 
 #endif  // NET_QUIC_CRYPTO_CURVE25519_KEY_EXCHANGE_H_