Add QuicStringPiece which is actually StringPiece.

net/quic/chromium/crypto/proof_verifier_chromium.h

 // Copyright 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_CHROMIUM_CRYPTO_PROOF_VERIFIER_CHROMIUM_H_
 #define NET_QUIC_CHROMIUM_CRYPTO_PROOF_VERIFIER_CHROMIUM_H_
 
 #include <map>
 #include <memory>
 #include <string>
@@ skipping 60 matching lines @@
                         TransportSecurityState* transport_security_state,
                         CTVerifier* cert_transparency_verifier);
   ~ProofVerifierChromium() override;
 
   // ProofVerifier interface
   QuicAsyncStatus VerifyProof(
       const std::string& hostname,
       const uint16_t port,
       const std::string& server_config,
       QuicVersion quic_version,
-      base::StringPiece chlo_hash,
+      QuicStringPiece chlo_hash,
       const std::vector<std::string>& certs,
       const std::string& cert_sct,
       const std::string& signature,
       const ProofVerifyContext* verify_context,
       std::string* error_details,
       std::unique_ptr<ProofVerifyDetails>* verify_details,
       std::unique_ptr<ProofVerifierCallback> callback) override;
   QuicAsyncStatus VerifyCertChain(
       const std::string& hostname,
       const std::vector<std::string>& certs,
@@ skipping 16 matching lines @@
 
   TransportSecurityState* const transport_security_state_;
   CTVerifier* const cert_transparency_verifier_;
 
   DISALLOW_COPY_AND_ASSIGN(ProofVerifierChromium);
 };
 
 }  // namespace net
 
 #endif  // NET_QUIC_CHROMIUM_CRYPTO_PROOF_VERIFIER_CHROMIUM_H_