message: Remove unnecessary static_cast in rtp_video_stream_receiver2
  Cr-Commit-Position: refs/heads/main@{#34977}
diff: @@ -861,8 +861,7 @@ void RtpVideoStreamReceiver2::OnAssembledFrame(
  void RtpVideoStreamReceiver2::OnCompleteFrames(
  RtpFrameReferenceFinder::ReturnVector frames) {
  for (auto& frame : frames) {
  - RtpFrameObject* rtp_frame = static_cast<RtpFrameObject*>(frame.get());
  - last_seq_num_for_pic_id_[rtp_frame->Id()] = rtp_frame->last_seq_num();
  + last_seq_num_for_pic_id_[frame->Id()] = frame->last_seq_num();
  last_completed_picture_id_ =
  std::max(last_completed_picture_id_, frame->Id());
  