GitLab

 - Nested controls are removed:
 The aria attributes of buttons inside <a> links are removed,
 so they won't be read twice by a screen reader.

 - Missing aria labels are added to radio buttons.

Bug: 853996
Change-Id: I9e009425c4d6cc0c03135856135fb830d96cf989
Reviewed-on: https://chromium-review.googlesource.com/1206810
Commit-Queue: Thomas Tangl <tangltom@chromium.org>
Reviewed-by: Scott Chen <scottchen@chromium.org>
Cr-Commit-Position: refs/heads/master@{#589371}