The DRM fight died the day the EFF, Cory Doctorow, Mozilla and other supposed champions of open data formats kept mum while DRM was being added to the HTML5 spec, this also killed off the idea of NPAPI browser plugins. Plugins were originally meant for exactly this sort of use - to display proprietary data within a browser by handing it off to another application - Flash and Java were the most popular but there were also media player plugins for DRMed media (both VLC & Windows Media Player for example, had browser plugins).