A chrome extension that looks into the current page for URLs of video files.
Once it finds them, it allows the user to download the videos or open them in a new tab (which, in the more exotic cases, also defaults to download instead of play).
The file extensions that it looks for are:
3g2, 3gp, 3gpp, asf, avi, divx, f4v, flv, h264, ifo, m2ts, m4v, mkv, mod, mov, mp4, mpeg, mpg, mswmm, mts, mxf, ogv, rm, swf, ts, vep, vob, webm, wlmp, wmv
Credits for the icons: