Remove QuicString wrapper for std::string

gfe-relnote: n/a (no functional change)
PiperOrigin-RevId: 238124961
Change-Id: I36e66a4326b4118d70effd356aef9734d2893763
diff --git a/quic/core/tls_handshaker_test.cc b/quic/core/tls_handshaker_test.cc
index ae9e3fc..2640651 100644
--- a/quic/core/tls_handshaker_test.cc
+++ b/quic/core/tls_handshaker_test.cc
@@ -2,12 +2,13 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
+#include <string>
+
 #include "net/third_party/quiche/src/quic/core/quic_utils.h"
 #include "net/third_party/quiche/src/quic/core/tls_client_handshaker.h"
 #include "net/third_party/quiche/src/quic/core/tls_server_handshaker.h"
 #include "net/third_party/quiche/src/quic/platform/api/quic_arraysize.h"
 #include "net/third_party/quiche/src/quic/platform/api/quic_ptr_util.h"
-#include "net/third_party/quiche/src/quic/platform/api/quic_string.h"
 #include "net/third_party/quiche/src/quic/platform/api/quic_test.h"
 #include "net/third_party/quiche/src/quic/test_tools/crypto_test_utils.h"
 #include "net/third_party/quiche/src/quic/test_tools/fake_proof_source.h"