Version: 57.0.2987.8 5716357fa4e765126615b02d3d6eb0da9b95a03a-refs/branch-heads/2987@{#54} (64-bit)
OS: Windows(7,8,8.1,10),Linux (14.04 LTS),Mac OS X(10.11.6, 10.12.1)

What steps will reproduce the problem?
1. Launch chrome, navigate to NTP and open devtools.
2. Now drag the browser window from bottom to top and then click on 'Customize and control devtools' button and go to 'More tools' options list.(Vertical Scroll bar appears).
3. Now drag the vertical scroll bar downwards and observe

Actual: 'More tools' option list disappears after dragging the vertical scroll bar downwards
Expected: 'More tools' option list should stay and not disappear after dragging the vertical scroll bar downwards in order to select the last option from list.

This is a non-regression issue, seen from M-54 series as 'Vertical scroll bar' appears from build # 54.0.2796.0 

Kindly review the attached screen cast for reference.
 

Deleted: Actual_video.mov 8.8 MB

Actual_video.mov 8.8 MB Download