UserAgent: Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/54.0.2840.71 Safari/537.36

Steps to reproduce the problem:
1. Load JS fiddle:
https://jsfiddle.net/xxkepffc/

2. Click on text box

3. Try to click on something else. Notice the browser has frozen. The more UI elements you have, the longer it freezes for.

Alternative method to replicate:

1. Create an <input type="text"> control

2. Assign a very large data:image/png URL to it via control.value property.

3. Click on the textbox

What is the expected behavior?
No freezing

What went wrong?
The browser freezes for a duration

Did this work before? Yes 48

Chrome version: 54.0.2840.71  Channel: stable
OS Version: 6.1 (Windows 7, Windows Server 2008 R2)
Flash Version: Shockwave Flash 23.0 r0

This doesn't happen in FF or IE/Edge, and did not used to happen in Chrome.