Add QuicStringPiece which is actually StringPiece.

net/quic/core/crypto/p256_key_exchange_test.cc

 // 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.
 
 #include "net/quic/core/crypto/p256_key_exchange.h"
 
 #include <memory>
 
 #include "testing/gtest/include/gtest/gtest.h"
 
@@ skipping 12 matching lines @@
     ASSERT_FALSE(alice_private.empty());
     ASSERT_FALSE(bob_private.empty());
     ASSERT_NE(alice_private, bob_private);
 
     std::unique_ptr<P256KeyExchange> alice(P256KeyExchange::New(alice_private));
     std::unique_ptr<P256KeyExchange> bob(P256KeyExchange::New(bob_private));
 
     ASSERT_TRUE(alice.get() != nullptr);
     ASSERT_TRUE(bob.get() != nullptr);
 
-    const base::StringPiece alice_public(alice->public_value());
-    const base::StringPiece bob_public(bob->public_value());
+    const QuicStringPiece alice_public(alice->public_value());
+    const QuicStringPiece bob_public(bob->public_value());
 
     std::string alice_shared, bob_shared;
     ASSERT_TRUE(alice->CalculateSharedKey(bob_public, &alice_shared));
     ASSERT_TRUE(bob->CalculateSharedKey(alice_public, &bob_shared));
     ASSERT_EQ(alice_shared, bob_shared);
   }
 }
 
 }  // namespace test
 }  // namespace net