Chrome
Go to View → Developer → JavaScript Console (OS X) or Press F12 (Windows)
Make sure you're in the the Console tab
Refresh the page and get a screenshot of everything in the log after it finishes loading
Firefox
Go to Tools → Browser Tools → Browser Console
Get a screenshot of everything in the log after it finishes loading
Safari
Go to Develop → Show JavaScript Console (If you don't see the Develop menu, head to the Navigation Bar and click Safari → Preferences... → Advanced and toggle on Show Develop menu in menu bar)
Make sure you're in the Console tab
Refresh the page and get a screenshot of everything in the log after it finishes loading