Chrome: waiting for www.site.com, how to know which resource is delaying the page load?

I found a way that I'm not sure it works in all cases, but it did for me. I used the Timeline tab, it's one of the tabs in Chrome Dev Tools.

1. Open Chrome Developer tools (F12 or CMD + Alt + I in Mac) and click the Timeline tab
2. Make sure you drag the grey timeline bar all the way to the right, you want to see the most recent section of events so you can find what's getting stuck:

3. Check just down below the records sidebar. If you don't see like in the capture, try toggling the icons, there are different view modes. Now, going all the way down I found these. It doesn't look like that's going well. Obviously some kind of infinite loop in some random code:

I couldn't find out if it was an extension itself or some other bit of code. Clicking through I only could find // Copyright 2014 The Chromium Authors. All rights reserved..

Checking in Incognito mode clear of extensions, the website loads just fine.

I'd also advise to check the Console tab to see if there are were any errors that might cause the infinite loading thing. You'll often find clues there.