Remove QuicString wrapper for std::string

gfe-relnote: n/a (no functional change)
PiperOrigin-RevId: 238124961
Change-Id: I36e66a4326b4118d70effd356aef9734d2893763
diff --git a/quic/core/crypto/p256_key_exchange_test.cc b/quic/core/crypto/p256_key_exchange_test.cc
index 32d6bf1..11d7bd8 100644
--- a/quic/core/crypto/p256_key_exchange_test.cc
+++ b/quic/core/crypto/p256_key_exchange_test.cc
@@ -5,9 +5,9 @@
 #include "net/third_party/quiche/src/quic/core/crypto/p256_key_exchange.h"
 
 #include <memory>
+#include <string>
 
 #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"
 
 namespace quic {