Remove QuicString wrapper for std::string

gfe-relnote: n/a (no functional change)
PiperOrigin-RevId: 238124961
Change-Id: I36e66a4326b4118d70effd356aef9734d2893763
diff --git a/quic/core/quic_sent_packet_manager.cc b/quic/core/quic_sent_packet_manager.cc
index bfafe43..93909b7 100644
--- a/quic/core/quic_sent_packet_manager.cc
+++ b/quic/core/quic_sent_packet_manager.cc
@@ -5,6 +5,7 @@
 #include "net/third_party/quiche/src/quic/core/quic_sent_packet_manager.h"
 
 #include <algorithm>
+#include <string>
 
 #include "net/third_party/quiche/src/quic/core/congestion_control/general_loss_algorithm.h"
 #include "net/third_party/quiche/src/quic/core/congestion_control/pacing_sender.h"
@@ -18,7 +19,6 @@
 #include "net/third_party/quiche/src/quic/platform/api/quic_flags.h"
 #include "net/third_party/quiche/src/quic/platform/api/quic_logging.h"
 #include "net/third_party/quiche/src/quic/platform/api/quic_map_util.h"
-#include "net/third_party/quiche/src/quic/platform/api/quic_string.h"
 
 namespace quic {