Chrome Version: 57.0.2958.3 (Official Build) a3121b731f3def912d78dbe9d15d0b93113ff1a9-refs/branch-heads/2958@{#4} 32/64 Bit.
OS: Windows (7,8,8.1,10),  Linux (14.04 LTS)

Steps:
1. Launch chrome and open a NTP, press F12 to open devtools and dock to bottom.
2. Press F1 to open settings page, click on any drop down menu and scroll down the overlay.
3. Press Enter key and observe the position of the overlay.

Actual: Drop down list misalignment is observed.

Expected: Drop down list should not be misplaced.

This is a regression issue broken in M-48.

Manual Regression range:
Good Build: 48.0.2540.0
Bad Build: 48.0.2541.0 

Narrow bisect:
https://chromium.googlesource.com/chromium/src/+log/4dfcf99da1c72086f44018b5976e80801dd682a5..8ada225e624feab9237180cdc3b8059c3a4a7a96?pretty=fuller&n=10000

Suspecting: 354871 ?

Kindly help to re-assign, if your changes are not cause for this issue. 

Note: Issue not seen on Mac OS.