GitLab

This CL fix the issue where user cannot use keyboard to access
global media controls dialog and detailed controls in quick settings.

Change-Id: I909e00e4e55ad0460886eb3ea3e231eaf0d79195
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2503399Reviewed-by: Tommy Steimel <steimel@chromium.org>
Reviewed-by: Tetsui Ohkubo <tetsui@chromium.org>
Commit-Queue: Jazz Xu <jazzhsu@chromium.org>
Cr-Commit-Position: refs/heads/master@{#821678}