If you get the ERR_INTERNET_DISCONNECTED error message while trying to access a web url on Google's Chrome Browser then its because your Internet Connection seems to be down! or, it may have so happened that you are on Wifi and while trying to access the URL your device was out of range.
How to diagnose this issue :
1. Go to System Preferences
2. Select Network
3. Click on Assist me..
4. Click on Diagnostics.. and follow the steps to know the issue.