Change window_update frame's byte_offset to max_data to incorporate IETF spec.

https://tools.ietf.org/html/draft-ietf-quic-transport-24#section-19.10

gfe-relnote: name change only. Not protected.
PiperOrigin-RevId: 281838511
Change-Id: I716cfd6856d8c9dd9981040f68bc0567feaedaee
diff --git a/quic/core/quic_stream.cc b/quic/core/quic_stream.cc
index 30c94f9..2037327 100644
--- a/quic/core/quic_stream.cc
+++ b/quic/core/quic_stream.cc
@@ -816,7 +816,7 @@
     return;
   }
 
-  if (flow_controller_->UpdateSendWindowOffset(frame.byte_offset)) {
+  if (flow_controller_->UpdateSendWindowOffset(frame.max_data)) {
     // Let session unblock this stream.
     session_->MarkConnectionLevelWriteBlocked(id_);
   }