Remove QuicString wrapper for std::string

gfe-relnote: n/a (no functional change)
PiperOrigin-RevId: 238124961
Change-Id: I36e66a4326b4118d70effd356aef9734d2893763
diff --git a/quic/core/frames/quic_connection_close_frame.h b/quic/core/frames/quic_connection_close_frame.h
index 1b909ce..b4be56b 100644
--- a/quic/core/frames/quic_connection_close_frame.h
+++ b/quic/core/frames/quic_connection_close_frame.h
@@ -6,11 +6,11 @@
 #define QUICHE_QUIC_CORE_FRAMES_QUIC_CONNECTION_CLOSE_FRAME_H_
 
 #include <ostream>
+#include <string>
 
 #include "net/third_party/quiche/src/quic/core/quic_error_codes.h"
 #include "net/third_party/quiche/src/quic/core/quic_types.h"
 #include "net/third_party/quiche/src/quic/platform/api/quic_export.h"
-#include "net/third_party/quiche/src/quic/platform/api/quic_string.h"
 
 namespace quic {