Version: 50.0.2661.37 (Official Build)4cf5e769930d697e8f617cff6a12f0d27dbfee89-refs/branch-heads/2661@{#250} (32/64-bit)
OS: All (Win 7- Aero enabled)

Precondition: Enable 'Media Router' flag from 'chrome://flags'.

What steps will reproduce the problem?
1) Launch chrome, go to NTP, right click and select 'Cast' option (Cast overlay opens).
2) Click on 'Cast to' dropdown, press Tab key 3 times (focus is on 'Cast tab' option).
3) Press Shift + Tab from keyboard and observe.

On pressing Shift + Tab, focus shifts to 'x' button.
 
On pressing Shift + Tab, focus should be on 'Share your screen' option.

This is a Regression issue broken in M-49, below is the bisect info
Manual bisect:
Good build: 49.0.2584.0 
Bad build: 49.0.2585.0

Narrow bisect URL:
https://chromium.googlesource.com/chromium/src/+log/cbe2f9589a0bebd848e4d5f1eb8cf6bede3c87d1..ee6999fe7f583ad8a33b64d375be95454aff613a?pretty=fuller&n=100

Suspecting: r363693

 

Deleted: cast_actual.mp4 452 KB

cast_actual.mp4 452 KB Download

Deleted: cast_expected.mp4 460 KB

cast_expected.mp4 460 KB Download