Brian beat me to it. I forgot to mention lead and silver. Brian makes the good point that lead likely won't take chrome (check with the chromer first), but it does work nicely for paint. It's THE old skool car customizing material. Unfortunately, it's poisonous, but it is an all-metal repair, and easy to work with. I'm not sure how silver takes chrome, but I think perhaps better than bronze. Either way, if you prepare it correctly (smoothed and highly polished), and your chrome is 'deep' (thick) enough and high quality, it probably won't show.
Similarly, if the metal is prepared properly (sanded [e.g. 220 grit], or otherwise has a fine 'tooth' to it, and *completely* cleaned [lacquer thinner or other strong non-residue solvent]), the Bondo is mixed well (proper proportions of hardener and resin), and applied at the correct ambient and [material] surface temp, then adhesion will be good, and it should not come out. I would think Bondo would also be easier to smooth out afterward, without risk of thinning out the surrounding areas of the tube in the process.
Bill Roberts
Jacksonville, OR