Add QuicStringPiece which is actually StringPiece.

net/quic/chromium/quic_chromium_client_session.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/chromium/quic_chromium_client_session.h"
 
 #include <utility>
 
 #include "base/callback_helpers.h"
 #include "base/location.h"
@@ skipping 901 matching lines @@
   logger_->OnCryptoHandshakeMessageSent(message);
 }
 
 void QuicChromiumClientSession::OnCryptoHandshakeMessageReceived(
     const CryptoHandshakeMessage& message) {
   logger_->OnCryptoHandshakeMessageReceived(message);
   if (message.tag() == kREJ || message.tag() == kSREJ) {
     UMA_HISTOGRAM_CUSTOM_COUNTS("Net.QuicSession.RejectLength",
                                 message.GetSerialized().length(), 1000, 10000,
                                 50);
-    base::StringPiece proof;
+    QuicStringPiece proof;
     UMA_HISTOGRAM_BOOLEAN("Net.QuicSession.RejectHasProof",
                           message.GetStringPiece(kPROF, &proof));
   }
 }
 
 void QuicChromiumClientSession::OnGoAway(const QuicGoAwayFrame& frame) {
   QuicSession::OnGoAway(frame);
   NotifyFactoryOfSessionGoingAway();
   port_migration_detected_ = frame.error_code == QUIC_ERROR_MIGRATING_PORT;
 }
@@ skipping 587 matching lines @@
 }
 
 size_t QuicChromiumClientSession::EstimateMemoryUsage() const {
   // TODO(xunjieli): Estimate |crypto_stream_|, QuicSpdySession's
   // QuicHeaderList, QuicSession's QuiCWriteBlockedList, open streams and
   // unacked packet map.
   return base::trace_event::EstimateMemoryUsage(packet_readers_);
 }
 
 }  // namespace net