Remove stream pointer from QuicSession::WritevData.

The session only uses the pointer to access stream_bytes_written. It could simply be replaced by a |is_retransmission| boolean. This change makes the boundary of streams and sessions clearer.

gfe-relnote: no behavior change, not protected.
PiperOrigin-RevId: 296504335
Change-Id: I349bdadadd923e9dcb5b03231ce351e4f1a25c96
diff --git a/quic/qbone/qbone_stream_test.cc b/quic/qbone/qbone_stream_test.cc
index 71f4260..dcd80bd 100644
--- a/quic/qbone/qbone_stream_test.cc
+++ b/quic/qbone/qbone_stream_test.cc
@@ -40,11 +40,11 @@
   ~MockQuicSession() override {}
 
   // Writes outgoing data from QuicStream to a string.
-  QuicConsumedData WritevData(QuicStream* stream,
-                              QuicStreamId id,
+  QuicConsumedData WritevData(QuicStreamId id,
                               size_t write_length,
                               QuicStreamOffset offset,
-                              StreamSendingState state) override {
+                              StreamSendingState state,
+                              bool is_retransmission) override {
     if (!writable_) {
       return QuicConsumedData(0, false);
     }