Chrome version : 51.0.2672.0 b4fd57023ade2863e463d3380456968dca6c8bcf-refs/heads/master@{#380022} 32/64 bit
OS : All (Win 7 aero enabled)

Steps : 
1. Launch Chrome, open devtools and Press F1 to open the 'Preferences'.
2. Go to 'Devices' and check-uncheck the first device from the list.
3. Now press 'Tab' key twice to move the focus on the first device in a list, hit 'Space Bar' and observe. 

Actual : Unable to select the 'Device' using 'Space Bar'.

Expected : Should be able to select a device using 'Space Bar. 

This is a non regression issue seen from 'M-42' series.(Build : 42.0.2294.0) 

Note : This is a newly added feature 'Devices' in Preferences section from Build : 42.0.2294.0
 

Deleted: Actual_focus.mov 7.0 MB

Actual_focus.mov 7.0 MB Download