Plumbing transport_op changes through
diff --git a/src/core/transport/transport.h b/src/core/transport/transport.h
index 7f6a37d..1acd665 100644
--- a/src/core/transport/transport.h
+++ b/src/core/transport/transport.h
@@ -85,6 +85,8 @@
 
 /** Transport op: a set of operations to perform on a transport as a whole */
 typedef struct grpc_transport_op {
+  /** called when processing of this op is done */
+  grpc_iomgr_closure *on_consumed;
   /** connectivity monitoring */
   grpc_iomgr_closure *on_connectivity_state_change;
   grpc_connectivity_state *connectivity_state;