Cast: cancel re-sending if a later nack packet says the receiver doesn't want it anymore

media/cast/rtcp/rtcp_sender_unittest.cc

Index: media/cast/rtcp/rtcp_sender_unittest.cc
diff --git a/media/cast/rtcp/rtcp_sender_unittest.cc b/media/cast/rtcp/rtcp_sender_unittest.cc
index 2074bdbb1d11d9f3353bfcdc8db5c6c521ee7c55..2bd807f3808500810e972a25a37b09cb5e45e018 100644
--- a/media/cast/rtcp/rtcp_sender_unittest.cc
+++ b/media/cast/rtcp/rtcp_sender_unittest.cc
@@ -63,6 +63,10 @@ class TestRtcpTransport : public transport::PacedPacketSender {
     return false;
   }
 
+  virtual void CancelSendingPacket(
+      const transport::PacketKey& packet_key) OVERRIDE {
+  }
+
   void SetExpectedRtcpPacket(scoped_ptr<Packet> packet) {
     expected_packet_.swap(*packet);
   }