UserAgent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_10_5) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/51.0.2681.0 Safari/537.36

Example URL:
http://output.jsbin.com/lubezo/3/

Steps to reproduce the problem:
1. Go to http://output.jsbin.com/lubezo/3/
2. Follow instructions (click "Focus" button, press Enter)

What is the expected behavior?
A newline is typed in the textarea

What went wrong?
Nothing is typed in the textarea

Does it occur on multiple sites: Yes

Is it a problem with a plugin? No 

Did this work before? N/A 

Does this work in other browsers? Yes 

Chrome version: 51.0.2681.0  Channel: canary
OS Version: OS X 10.10.5
Flash Version: Shockwave Flash 21.0 r0

This is worse in Canary than stable Chrome. In stable Chrome merely typing Enter doesn't work. In Canary, no typing at all works.

Firefox doesn't have this problem (nor, reportedly, IE), but Safari also does: https://bugs.webkit.org/show_bug.cgi?id=155615