Remove using namespace in net/quic/quic_stream_sequencer.h

net/quic/crypto/aes_128_gcm_12_decrypter_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/crypto/aes_128_gcm_12_decrypter.h"
 
 #include "net/quic/test_tools/quic_test_utils.h"
 
 using base::StringPiece;
+using std::string;
 
 namespace {
 
 // The AES GCM test vectors come from the file gcmDecrypt128.rsp
 // downloaded from http://csrc.nist.gov/groups/STM/cavp/index.html on
 // 2013-02-01. The test vectors in that file look like this:
 //
 // [Keylen = 128]
 // [IVlen = 96]
 // [PTlen = 0]
@@ skipping 307 matching lines @@
 
       ASSERT_EQ(pt.length(), decrypted->length());
       test::CompareCharArraysWithHexError("plaintext", decrypted->data(),
                                           pt.length(), pt.data(), pt.length());
     }
   }
 }
 
 }  // namespace test
 }  // namespace net