In QUIC version >= 38, enables random padding of size [1, 256]

net/quic/core/quic_packet_creator.cc

Index: net/quic/core/quic_packet_creator.cc
diff --git a/net/quic/core/quic_packet_creator.cc b/net/quic/core/quic_packet_creator.cc
index 823959bb672ac712bf205e53cd1f93c125508ae5..94f467affe5860a9edfc6556f31402f617715c8b 100644
--- a/net/quic/core/quic_packet_creator.cc
+++ b/net/quic/core/quic_packet_creator.cc
@@ -14,6 +14,7 @@
 #include "net/quic/core/quic_utils.h"
 #include "net/quic/platform/api/quic_aligned.h"
 #include "net/quic/platform/api/quic_bug_tracker.h"
+#include "net/quic/platform/api/quic_flag_utils.h"
 #include "net/quic/platform/api/quic_logging.h"
 #include "net/quic/platform/api/quic_string_piece.h"
 
@@ -645,6 +646,7 @@ void QuicPacketCreator::MaybeAddPadding() {
     packet_.num_padding_bytes =
         std::min<int16_t>(pending_padding_bytes_, BytesFree());
     pending_padding_bytes_ -= packet_.num_padding_bytes;
+    QUIC_FLAG_COUNT(quic_reloadable_flag_quic_enable_random_padding);
   }
 
   bool success =