Only create H264 frames if there are no gaps in the packet sequence number.

webrtc/video/rtp_stream_receiver.cc

Index: webrtc/video/rtp_stream_receiver.cc
diff --git a/webrtc/video/rtp_stream_receiver.cc b/webrtc/video/rtp_stream_receiver.cc
index 99d0cc893f25f19d606fdfdfd09827f447be3b79..c14dee8b8f4c9b51c870a2e6ab71fb1e30df8811 100644
--- a/webrtc/video/rtp_stream_receiver.cc
+++ b/webrtc/video/rtp_stream_receiver.cc
@@ -244,6 +244,7 @@ int32_t RtpStreamReceiver::OnReceivedPayloadData(
   // correctly calculate frame references.
   if (packet.sizeBytes == 0) {
     reference_finder_->PaddingReceived(packet.seqNum);
+    packet_buffer_->PaddingReceived(packet.seqNum);
     return 0;
   }