The profile appears to be in use by another Chromium process (19846) on another computer. Chromium has locked the profile so that it doesn't get corrupted. If you are sure no other processes are using this profile, you can unlock the profile and relaunch Chromium.
Run rm -f ~/.config/chromium/SingletonLock. This will delete the singleton lock for chromium. The lock was left after chromium wasn't shut down properly last time.
