Groundwork for cancelling quartc streams after a deadline is exceeded.

net/quic/quartc/quartc_session_interface.h

Index: net/quic/quartc/quartc_session_interface.h
diff --git a/net/quic/quartc/quartc_session_interface.h b/net/quic/quartc/quartc_session_interface.h
index f4d8845313a71110d251d924f11baf014f0a7425..01e630ba817565d0a67d187432957fb7884b530f 100644
--- a/net/quic/quartc/quartc_session_interface.h
+++ b/net/quic/quartc/quartc_session_interface.h
@@ -9,6 +9,8 @@
 #include <stdint.h>
 #include <string>
 
+#include "net/quic/core/quic_error_codes.h"
+#include "net/quic/core/quic_types.h"
 #include "net/quic/quartc/quartc_stream_interface.h"
 
 namespace net {
@@ -48,6 +50,13 @@ class QuartcSessionInterface {
   virtual QuartcStreamInterface* CreateOutgoingStream(
       const OutgoingStreamParameters& params) = 0;
 
+  // If the given stream is still open, sends a reset frame to cancel it.
+  // Note:  This method cancels a stream by QuicStreamId rather than by pointer
+  // (or by a method on QuartcStreamInterface) because QuartcSession (and not
+  // the caller) owns the streams.  Streams may finish and be deleted before the
+  // caller tries to cancel them, rendering the caller's pointers invalid.
+  virtual void CancelStream(QuicStreamId stream_id) = 0;
+
   // Send and receive packets, like a virtual UDP socket. For example, this
   // could be implemented by WebRTC's IceTransport.
   class PacketTransport {