GitLab

This CL makes it such that the volume level is read out as a percentage
in aria. This CL also amplifies how the accessibility information is
given to aria, by setting attributes instead of explicitly creating
accessibility nodes.

Bug: 905024
Change-Id: I0ee5a91215669f39c7394d3c8f113ae83a74cf00
Reviewed-on: https://chromium-review.googlesource.com/c/1337298Reviewed-by: Nico Weber <thakis@chromium.org>
Reviewed-by: Dominic Mazzoni <dmazzoni@chromium.org>
Reviewed-by: Mounir Lamouri <mlamouri@chromium.org>
Commit-Queue: CJ DiMeglio <lethalantidote@chromium.org>
Cr-Commit-Position: refs/heads/master@{#612160}