At the moment following version of chromium-browser is used
Chromium 56.0.2924.84 Built on Ubuntu 14.04, running on Raspbian 8.0
Older version of pi player (1.7.2 and older) used uzbl browser and they continue to use uzbl even if they are upgraded to newer versions. To upgrade to chromium in such cases, it is better to prepare a fresh SD card with latest image.
If you would like to know more about the configuration of the browser, please write to us.