Chrome version : 50.0.2661.26 0abdf9cbb43ea5639687aa21a2bcb206b1dc6d7b-refs/branch-heads/2661@{#169}  (32/64 bit)
OS : All (Win 7 aero enabled)

Steps : 
1. Launch Chrome, open NTP, go to devtools and click on 'Toggle device toolbar'.
2. Click in the 'Width' text box and press 'Tab' key twice to move focus on 'Zoom' drop down.
3. Hit 'Space Bar' and observe.

Actual : In devtools, Zoom drop down list does not open using 'Space Bar'
Expected : Zoom drop down list should open using 'Space Bar'

This is a regression issue broken in 'M-50' and below is the manual regression and narrow bisect info.
Good build : 50.0.2655.0
Bad build : 50.0.2656.0

Narrow Bisect :
https://chromium.googlesource.com/chromium/src/+log/5e288c8b55f4ab8173485fa69f7ee59e2c6a3a5f..ae67350c3a10889adb6bf3f47002227546245737?pretty=fuller&n=10000

Suspecting : 376345 from narrow bisect

@dgozman : Could you please help to reassign if your change is not the cause for this issue

 

Deleted: Actual_dev_zoom.mp4 977 KB

Actual_dev_zoom.mp4 977 KB Download

Deleted: Expected_dev_zoom.mp4 730 KB

Expected_dev_zoom.mp4 730 KB Download