Cast: Deduplicate packets in paced sender and always send older packets first

media/cast/transport/rtp_sender/rtp_sender.cc

Index: media/cast/transport/rtp_sender/rtp_sender.cc
diff --git a/media/cast/transport/rtp_sender/rtp_sender.cc b/media/cast/transport/rtp_sender/rtp_sender.cc
index f1752855fbeecaf3462ef8dffa0d590d1a884067..9f891193a53c091cc3b2bb0ca7b859331cfb6a49 100644
--- a/media/cast/transport/rtp_sender/rtp_sender.cc
+++ b/media/cast/transport/rtp_sender/rtp_sender.cc
@@ -78,7 +78,7 @@ void RtpSender::ResendPackets(
            missing_frames_and_packets.begin();
        it != missing_frames_and_packets.end();
        ++it) {
-    PacketList packets_to_resend;
+    SendPacketVector packets_to_resend;
     uint8 frame_id = it->first;
     const PacketIdSet& packets_set = it->second;
     bool success = false;
@@ -96,7 +96,7 @@ void RtpSender::ResendPackets(
           VLOG(3) << "Resend " << static_cast<int>(frame_id) << ":"
                   << packet_id;
           // Set a unique incremental sequence number for every packet.
-          PacketRef packet = packets_to_resend.back();
+          PacketRef packet = packets_to_resend.back().second;
           UpdateSequenceNumber(&packet->data);
           // Set the size as correspond to each frame.
           ++packet_id;
@@ -114,7 +114,7 @@ void RtpSender::ResendPackets(
         if (success) {
           VLOG(3) << "Resend " << static_cast<int>(frame_id) << ":"
                   << packet_id;
-          PacketRef packet = packets_to_resend.back();
+          PacketRef packet = packets_to_resend.back().second;
           UpdateSequenceNumber(&packet->data);
         }
       }