If your Google Chrome browser is acting awkward with fonts like in the picture (displays all “A” characters) instead of serif fonts or of all fonts, you may need to clean your Mac OS X Font Cache.
Here’s how to do it.
To clear the current user’s font cache: quit all running applications (otherwise, you may see font oddities after using the command), then open Terminal (in Applications -> Utilities) and run this command.
atsutil databases -removeUser
If you want to remove the font cache for all users, use this command, and provide your admin password when asked:
sudo atsutil databases -remove
Then you should stop and restart the ATS server with these commands:
$ atsutil server -shutdown
$ atsutil server -ping
A restart or a logout-login is recommended, especially if something still looks odd.
There are plenty of tools out there to access these maintenance processes that are built in the system, without having to deal with the command line. I’ve been using Onyx, but there are a few alternatives (MacJanitor, Cocktail) if you want to spend some time searching for the best.