Remove using namespace in net/quic/quic_stream_sequencer.h

net/quic/crypto/crypto_utils_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/crypto_utils.h"
 
 #include "net/quic/test_tools/quic_test_utils.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
+using std::string;
+
 namespace net {
 namespace test {
 namespace {
 
 TEST(CryptoUtilsTest, IsValidSNI) {
   // IP as SNI.
   EXPECT_FALSE(CryptoUtils::IsValidSNI("192.168.0.1"));
   // SNI without any dot.
   EXPECT_FALSE(CryptoUtils::IsValidSNI("somedomain"));
   // Invalid RFC2396 hostname
@@ skipping 102 matching lines @@
                                           result.length(),
                                           expected.data(),
                                           expected.length());
     }
   }
 }
 
 }  // namespace
 }  // namespace test
 }  // namespace net