I'm running
www/iridium (privacy enhanced chrome fork) on a new 6.5 install without issues. I did save my prior ~/.config/iridium and reused it on the new install.
This would suggest several things you could try.
1) See if you get the same behavior with Iridium.
2) Copy your ~/.config/chromium over from another Linux/BSD system - perhaps unveil is preventing the writing of a needed run option to your home directory.
3) If Iridium works, rename the ~/.config directory to chromium.