Add QuicStringPiece which is actually StringPiece.

net/quic/core/crypto/p256_key_exchange_test.cc

Index: net/quic/core/crypto/p256_key_exchange_test.cc
diff --git a/net/quic/core/crypto/p256_key_exchange_test.cc b/net/quic/core/crypto/p256_key_exchange_test.cc
index 564382cbd503f99619b0adcc7301b5b818c4659b..7ff40220b97a4360d840869adda1e886dec127d3 100644
--- a/net/quic/core/crypto/p256_key_exchange_test.cc
+++ b/net/quic/core/crypto/p256_key_exchange_test.cc
@@ -30,8 +30,8 @@ TEST(P256KeyExchange, SharedKey) {
     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));