Chrome Version: 57.0.2987.37 (Official Build) (64-bit)47a57c88d21c9db6c802e723966c0d7a1e5a991c-refs/branch-heads/2987@{#374} 64 bit
OS: Mac (10.11.6,10.12.1)

Steps:
1. Launch Chrome, navigate to chrome://settings and set 'Font size' to 'Large'.
2. Go to NTP and select Cast open from context menu and observe.

Actual: Unwanted white line is seen on cast overlay after setting ''Font size' to 'Large'.

Expected: No white line should be seen on cast overlay after setting 'Font size' to 'Large'.

This is a regression issue broken in M-50, below is bisect info.

Good build: 50.0.2637.0
Bad build: 50.02638.0

Narrow bisect:
https://chromium.googlesource.com/chromium/src/+log/50ac11db71e0311d95d6bfd5a4912bf98cebe64c..eec02e1394905a98671bc640cd05504698dccc8f?pretty=fuller&n=30

Suspecting: r372809 ?

Please help to re-assign if your change is not the cause for this issue

Note: This is Mac OS specific issue, not seen on Windows and Linux OS
 

Deleted: Actual_result.mov 3.3 MB

Actual_result.mov 3.3 MB Download

Deleted: Expected_result.mov 2.4 MB

Expected_result.mov 2.4 MB Download