Version: 58.0.2999.5 6c86d19d495b8ab045d74b3c19addca0fc1ffd48-refs/branch-heads/2999@{#5}
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 open emulated view and drag the LHS resize button of NTP page from LHS to RHS ,observe

Actual: Resize button disappears after dragging it from LHS to RHS
Expected: Resize button should not disappear after dragging it from LHS to RHS

This is a non-regression issue, seen from M-50 series as LHS 'Resize button' appears from build # 50.0.2636.0

Kindly review the attached screen cast for reference.
 

Deleted: Actual_video.mp4 1.0 MB

	Actual_video.mp4 1.0 MB View Download