Remove using namespace in net/quic/quic_stream_sequencer.h

net/tools/quic/quic_spdy_client_stream_test.cc

Index: net/tools/quic/quic_spdy_client_stream_test.cc
diff --git a/net/tools/quic/quic_spdy_client_stream_test.cc b/net/tools/quic/quic_spdy_client_stream_test.cc
index 090e2da7bbc9d7c6e751d3f9894da0ee967957e3..62d824df71cb604c66a5a279ae48569e630e6731 100644
--- a/net/tools/quic/quic_spdy_client_stream_test.cc
+++ b/net/tools/quic/quic_spdy_client_stream_test.cc
@@ -4,6 +4,8 @@
 
 #include "net/tools/quic/quic_spdy_client_stream.h"
 
+#include <string>
+
 #include "base/strings/string_number_conversions.h"
 #include "net/quic/quic_utils.h"
 #include "net/quic/test_tools/quic_test_utils.h"
@@ -16,6 +18,7 @@
 
 using net::test::DefaultQuicConfig;
 using net::test::SupportedVersions;
+using std::string;
 using testing::StrictMock;
 using testing::TestWithParam;