Chrome Version: 49.0.2623.110 (Official Build) 575538bc320e213510be1e66f3521382e615129d-refs/branch-heads/2623@{#657} 32/64-bit.
OS: Windows(Aero enabled), Mac.

What steps will reproduce the problem?
1. Launch chrome, open 'DevTools' window and go to 'Settings' page using 'F1' key.
2. Keep focus on 'Color format' drop down list (Using double click) under 'Element' section.
3. Now, press 'H' key from keyboard and observe the drop down list of 'Color format'.

Nothing happens on pressing 'H' key from keyboard.
Corresponding color format (HEx/HSL) should get selected in drop-down list.

This is a regression issue, broken in M-46 series, below are manual regression range and bisect info.

Manual regression range:
Good build: 46.0.2471.2 
Bad build: 46.0.2473.0

Narrow bisect:
https://chromium.googlesource.com/chromium/src/+log/d34042912daf7277cf5f0c6d890be6b0ca54f8cd..04c8ac0345fd29aeedeaed091999b6307197e463?pretty=fuller&n=10

Blink bisect:
https://chromium.googlesource.com/chromium/blink/+log/39495a923bb16c207c55d752b40ca5b30a6e060e..b2b9135664b0337e297d37bc50673504b0c6eb61?pretty=fuller&n=100

Suspecting: 199943

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

Note: 
1. This issue is only reproducible for 'H' alphabet.
2. This issue is reproducible for all the drop-down list in 'Settings' page.
3. This issue is not seen on 'Linux' OS.

Kindly review the attached screencast for reference.
 

Deleted: Actual_behaviour.mp4 657 KB

Actual_behaviour.mp4 657 KB Download

Deleted: Expected_behavior.mp4 632 KB

Expected_behavior.mp4 632 KB Download