Cast: Don't cancel re-transmission for some cases

media/cast/video_sender/video_sender.cc

Index: media/cast/video_sender/video_sender.cc
diff --git a/media/cast/video_sender/video_sender.cc b/media/cast/video_sender/video_sender.cc
index f228c1b3d1af1cedc5d376e41b690a5345132a79..66b2ec1d4b9d4747f6883c9799c5f89dadb3b282 100644
--- a/media/cast/video_sender/video_sender.cc
+++ b/media/cast/video_sender/video_sender.cc
@@ -316,8 +316,10 @@ void VideoSender::OnReceivedCastFeedback(const RtcpCastMessage& cast_feedback) {
     // Only count duplicated ACKs if there is no NACK request in between.
     // This is to avoid aggresive resend.
     duplicate_ack_counter_ = 0;
+
+    // A NACK is also used to cancel pending re-transmissions.
     transport_sender_->ResendPackets(
-        false, cast_feedback.missing_frames_and_packets_);
+        false, cast_feedback.missing_frames_and_packets_, true);
     uint32 new_bitrate = 0;
     if (congestion_control_.OnNack(rtt, &new_bitrate)) {
       UpdateBitrate(new_bitrate);
@@ -367,7 +369,11 @@ void VideoSender::ResendForKickstart() {
   missing_frames_and_packets.insert(
       std::make_pair(last_sent_frame_id_, missing));
   last_send_time_ = cast_environment_->Clock()->NowTicks();
-  transport_sender_->ResendPackets(false, missing_frames_and_packets);
+
+  // Sending this extra packet is to kick-start the session. There is
+  // no need to optimize re-transmission for this case.
+  transport_sender_->ResendPackets(false, missing_frames_and_packets,
+                                   false);
 }
 
 void VideoSender::UpdateBitrate(int new_bitrate) {