Remove using namespace in net/quic/quic_stream_sequencer.h

net/quic/quic_reliable_client_stream_test.cc

Index: net/quic/quic_reliable_client_stream_test.cc
diff --git a/net/quic/quic_reliable_client_stream_test.cc b/net/quic/quic_reliable_client_stream_test.cc
index caa697aa4843a3b2b43f2c46a50f125b0b310611..33e4bb86d651e6aa096922f8f0b8e5e2dd312437 100644
--- a/net/quic/quic_reliable_client_stream_test.cc
+++ b/net/quic/quic_reliable_client_stream_test.cc
@@ -4,6 +4,8 @@
 
 #include "net/quic/quic_reliable_client_stream.h"
 
+#include <string>
+
 #include "net/base/net_errors.h"
 #include "net/base/test_completion_callback.h"
 #include "net/quic/quic_client_session.h"
@@ -12,6 +14,7 @@
 #include "net/quic/test_tools/quic_test_utils.h"
 #include "testing/gmock/include/gmock/gmock.h"
 
+using std::string;
 using testing::AnyNumber;
 using testing::Return;
 using testing::StrEq;