UserAgent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_10_2) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/51.0.2704.103 Safari/537.36

Steps to reproduce the problem:
1. Cause infinite loop
2. Try to pause it by opening devtools to hit the pause button.

What is the expected behavior?
That should work.

What went wrong?
It's not possible, the UI is hung.

Did this work before? N/A 

Chrome version: 51.0.2704.103  Channel: n/a
OS Version: OS X 10.10.2
Flash Version: Shockwave Flash 22.0 r0

An option could be to add a debugger statement where we think it happens, but this is not always possible as we may not know the location, or we may not have access to the source code.