Add QuicStringPiece which is actually StringPiece.

net/quic/core/crypto/null_encrypter_test.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/core/crypto/null_encrypter.h"
 #include "net/quic/test_tools/quic_test_utils.h"
 
-using base::StringPiece;
-
 namespace net {
 namespace test {
 
 class NullEncrypterTest : public ::testing::TestWithParam<bool> {};
 
 TEST_F(NullEncrypterTest, EncryptClient) {
   unsigned char expected[] = {
       // fnv hash
       0x97, 0xdc, 0x27, 0x2f, 0x18, 0xa8, 0x56, 0x73, 0xdf, 0x8d, 0x1d, 0xd0,
       // payload
@@ skipping 73 matching lines @@
 
 TEST_F(NullEncrypterTest, GetCiphertextSize) {
   NullEncrypter encrypter(Perspective::IS_CLIENT);
   EXPECT_EQ(1012u, encrypter.GetCiphertextSize(1000));
   EXPECT_EQ(112u, encrypter.GetCiphertextSize(100));
   EXPECT_EQ(22u, encrypter.GetCiphertextSize(10));
 }
 
 }  // namespace test
 }  // namespace net