In QUIC, send data is copied to streams rather than frames. Protected by FLAGS_quic_reloadable_flag…

net/quic/core/quic_stream.cc

Index: net/quic/core/quic_stream.cc
diff --git a/net/quic/core/quic_stream.cc b/net/quic/core/quic_stream.cc
index 4e8d7a65835736b7d700319e634732dc099e6aab..e8583b62c043d0d8102a3b5797026167452e67b7 100644
--- a/net/quic/core/quic_stream.cc
+++ b/net/quic/core/quic_stream.cc
@@ -77,7 +77,8 @@ QuicStream::QuicStream(QuicStreamId id, QuicSession* session)
       stream_contributes_to_connection_flow_control_(true),
       busy_counter_(0),
       add_random_padding_after_fin_(false),
-      ack_listener_(nullptr) {
+      ack_listener_(nullptr),
+      send_buffer_(session->connection()->helper()->GetBufferAllocator()) {
   SetFromConfig();
 }
 
@@ -532,6 +533,9 @@ void QuicStream::OnStreamFrameDiscarded(const QuicStreamFrame& frame) {
   if (frame.fin) {
     fin_outstanding_ = false;
   }
+  if (session_->streams_own_data() && frame.data_length > 0) {
+    send_buffer_.RemoveStreamFrame(frame.offset, frame.data_length);
+  }
   if (!IsWaitingForAcks()) {
     session_->OnStreamDoneWaitingForAcks(id_);
   }
@@ -541,4 +545,19 @@ bool QuicStream::IsWaitingForAcks() const {
   return stream_bytes_outstanding_ || fin_outstanding_;
 }
 
+void QuicStream::SaveStreamData(QuicIOVector iov,
+                                size_t iov_offset,
+                                QuicStreamOffset offset,
+                                QuicByteCount data_length) {
+  DCHECK_LT(0u, data_length);
+  send_buffer_.SaveStreamData(iov, iov_offset, offset, data_length);
+}
+
+bool QuicStream::WriteStreamData(QuicStreamOffset offset,
+                                 QuicByteCount data_length,
+                                 QuicDataWriter* writer) {
+  DCHECK_LT(0u, data_length);
+  return send_buffer_.WriteStreamData(offset, data_length, writer);
+}
+
 }  // namespace net