Chrome Version: 51.0.2704.79 (Official Build)e300a2fe0cfcf2cc3bb5d753043e73967c33c749-refs/branch-heads/2704@{#690} 32/64-bit.
OS: Windows(7,8,10), Linux(Ubuntu 14.04 LTS) 

URL: https://www.google.com/intl/en/chrome/browser/welcome.html

What steps will reproduce the problem?
1. Launch chrome, go to above URL and click on 'Translate to English' option from rt. click context menu.
2. Click on 'options' link on translate bubble and then click to open 'Page language' drop down list.
3. Now put the mouse pointer on up/down arrow of drop down list and wait till it completely scrolled and observe.

Up/down arrow of drop down list doesn't disable when it's completely scrolled. 
Up/down arrow of drop down list should get disabled when it's completely scrolled.

This is a non regression issue, seen from M-30 series.

Note: This issue is not seen on 'Mac' OS.

Kindly review the attached screen-cast for reference. 
 

Deleted: Actual behavior.mp4 831 KB

Actual behavior.mp4 831 KB Download