Chrome Version : 51.0.2704.7 a8bebc2b0cd3e3018b7c9f6ac698f04dd226abba-refs/branch-heads/2704@{#48} (32/64-bit)
OS : All(Win 7 aero enabled).
Url : https://www.google.co.in/?gfe_rd=cr&ei=2iYPV6rRILLT8gfA3ajYAw

What steps will reproduce the problem?
1. Launch chrome and navigate to above url.
2. Open devtools and select emulated view and go to 'Elements' section.
3. Now press 'Ctrl + F' keys from keyboard to open 'Find by' search box and enter 'div' to search.
4. Now press 'Esc' key from keyboard to open console drawer and drag it upwards to 'Find by' search box area and click on down arrow button of 'Find by' search box and observe

Actual: Flickering is seen after clicking on down arrow button of Find by search box in devtools.
Expected: Flickering should not be seen after clicking on down arrow button of Find by search box in devtools.

This is a regression issue broken in 'M-45' and below is the manual regression and Narrow bisect info :
Good Build: 45.0.2405.0
Bad Build:  45.0.2407.0

Narrow bisect:
https://chromium.googlesource.com/chromium/src/+log/1f9c03ff842490fd24fd5cd93920ad57b3479a1e..19452cebfcffc0566cfb23f80ba4664a5c2d86bb?pretty=fuller&n=50

Blink bisect :
https://chromium.googlesource.com/chromium/blink/+log/548ec29cc8098e2f7cb07cc48f0bef6416458ea4..4efc09a4fde2d5ae0ba08bc049848c43fa7ecaa9?pretty=fuller&n=50

Suspecting: 195500 from Blink bisect

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

Deleted: Actual_video.mp4 904 KB

Actual_video.mp4 904 KB Download

Deleted: Expected_video.mp4 1.1 MB

Expected_video.mp4 1.1 MB Download