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_session.cc b/quic/core/quic_session.cc
index 98e4f4e..2d9477f 100644
--- a/quic/core/quic_session.cc
+++ b/quic/core/quic_session.cc
@@ -5,6 +5,7 @@
 #include "net/third_party/quiche/src/quic/core/quic_session.h"
 
 #include <cstdint>
+#include <string>
 #include <utility>
 
 #include "net/third_party/quiche/src/quic/core/quic_connection.h"
@@ -17,7 +18,6 @@
 #include "net/third_party/quiche/src/quic/platform/api/quic_map_util.h"
 #include "net/third_party/quiche/src/quic/platform/api/quic_stack_trace.h"
 #include "net/third_party/quiche/src/quic/platform/api/quic_str_cat.h"
-#include "net/third_party/quiche/src/quic/platform/api/quic_string.h"
 
 using spdy::SpdyPriority;