GitLab

Don't hide the mute button for anything with audio when using the new
media playback UI.  The old behavior is unchanged.

Note that on clank, we don't really know if an audio track is present,
so we always show the mute button.

BUG=521789

Review URL: https://codereview.chromium.org/1303553003

git-svn-id: svn://svn.chromium.org/blink/trunk@200908 bbb929c8-8fbe-4397-9dbb-9b2b20218538