How to unhide filtered messages in Chrome developer Tools 60
If you right-click on the surface of the console, you can go to filter, then unhide all. A few items still seem to be hidden for me though
Update (Oct '18):
It looks like it got moved to a textbox at the top of the console, named "Filter" and a dropbox box next to it for the levels.
You can also press f1 while in the developer console and then select the "restore to default" button in the bottom right.