Chrome Version:54.0.2806.0 (Official Build) 4e19044900929958a03fc2d5c07cb2cc5aab47ff-refs/heads/master@{#407375}(32/64 bit)
OS: Windows(7,8,10), Mac(10.11.4,10.10.5),Linux (14.04 LTS)

What steps will reproduce the problem?
1.Launch chrome, navigate to chrome://md-settings page.
2.Click on 'Manage search engine', then click on iron icon near to the Settings text(Side nav menu opens).
3.Click on ‘Advanced’ drop down and observe.

Actual: Weird behaviour is seen after step 3.
Expected: No such behaviour should seen after step 3.

This is a regression issue, broken in 'M-53', below is manual bisect and narrow bisect:

Good Build : 53.0.2777.0
Bad Build : 53.0.2778.0

Narrow Bisect info:
https://chromium.googlesource.com/chromium/src/+log/9de57cf7d69d8b30d5ae66c902d6a9d501e68664..c6cf0184697c9b473b78cdc0e44490a73da95486?pretty=fuller&n=100

Suspecting: r401711

 

Deleted: Actual.mov 2.1 MB

Actual.mov 2.1 MB Download

Deleted: Expected.mov 2.9 MB

Expected.mov 2.9 MB Download