Could you program a (switchable) extension working like "IF TMP changed THEN IF change = sympathic mediafile, THEN play that new mediafile" .....
Chrome/Chromium browser in my (puppy)Linux does not support mediaplayers, only flashplayer and I like the Chrom* speed and stability especially on older hardware. It has "download" though for which the folder can be set/varied. I have set VLC as my "default" mediaplayer so only on mighty rare occasions another player needs to jump in.