Chrome Version : 54.0.2832.0 (Official Build) 6c7eba987dc174e1522212efec1676619aa26a5a-refs/heads/master@{#412743} (64-bit)
OS: Mac (10.10.5)(10.11.5), Windows (7,8,8.1,10), Linux(14.04 LTS)

What steps will reproduce the problem?
1. Launch chrome and navigate to chrome://md-settings/advanced.
2. Scroll down the page and expand the ‘Languages’ section.
3. Now click on both the ‘More action’ icon and observe.

Actual : Unnecessarily both the drop down lists are seen at a same time.
Expected : Only one drop down list should be displayed at a time. 

This is a regression issue broken in M-54, below is the Manual Regression and Narrow Bisect info.
Good build: 54.0.2827.0
Bad build: 54.0.2828.0

Narrow Bisect : 
https://chromium.googlesource.com/chromium/src/+log/4484fdda108318287327f618c5b3e464f7dc10ae..af4de58dba85c0556a4ca0716c8154e8dbfcfde7?pretty=fuller&n=10000

Suspecting: r411716 from narrow bisect.
 

Deleted: Actual.mov 4.2 MB

Actual.mov 4.2 MB Download

Deleted: Expected.mov 3.3 MB

Expected.mov 3.3 MB Download