Fix a few spurious string allocations in QuicCryptoServerStream and QuicCryptoStream. No functional…

net/quic/quic_crypto_stream.cc

 // 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.
 
 #include "net/quic/quic_crypto_stream.h"
 
 #include <string>
 
 #include "base/strings/string_piece.h"
 #include "net/quic/crypto/crypto_handshake.h"
@@ skipping 54 matching lines @@
   SendHandshakeMessage(message, nullptr);
 }
 
 void QuicCryptoStream::SendHandshakeMessage(
     const CryptoHandshakeMessage& message,
     QuicAckListenerInterface* listener) {
   DVLOG(1) << ENDPOINT << "Sending " << message.DebugString();
   session()->OnCryptoHandshakeMessageSent(message);
   const QuicData& data = message.GetSerialized();
   // TODO(wtc): check the return value.
-  WriteOrBufferData(string(data.data(), data.length()), false, listener);
+  WriteOrBufferData(StringPiece(data.data(), data.length()), false, listener);
 }
 
 bool QuicCryptoStream::ExportKeyingMaterial(StringPiece label,
                                             StringPiece context,
                                             size_t result_len,
                                             string* result) const {
   if (!handshake_confirmed()) {
     DLOG(ERROR) << "ExportKeyingMaterial was called before forward-secure"
                 << "encryption was established.";
     return false;
@@ skipping 13 matching lines @@
       crypto_negotiated_params_.initial_subkey_secret, "EXPORTER-Token-Binding",
       /* context= */ "", 32, result);
 }
 
 const QuicCryptoNegotiatedParameters&
 QuicCryptoStream::crypto_negotiated_params() const {
   return crypto_negotiated_params_;
 }
 
 }  // namespace net