Here's the fix. Type into your browser address bar:
chrome://flags/On the resulting page, click the link to Disable under Disable DirectWrite Windows
This will disable the use of the new experimental DirectWrite font rendering system.
A box will appear at the bottom of your browser saying :
Your changes will take effect the next time you relaunch Google Chrome.
Click the box to Relaunch Chrome that will appear underneath - and voila. Your fonts are back to normal.