Remove -internals-media-controls-text-track-list* as web exposed CSS selector.

It has been deprecated since M57 and the usage is quite low now.

Intent to Remove: https://groups.google.com/a/chromium.org/d/msg/blink-dev/ngqnEQg7xac/7YgrxvuXAgAJ

BUG=678285
R=jochen@chromium.org

Review-Url: https://codereview.chromium.org/2750583003
Cr-Commit-Position: refs/heads/master@{#456682}
5 files changed