GitLab

To test, open a video that has a WebVTT captions file. For example, https://www.iandevlin.com/html5test/webvtt/html5-video-webvtt-sample.html is a nice example.

Introduce new background opacity text track property for webvtt captions and wire it to apply opacity to the WebVTT caption HTML element.

Bug: 897730
Change-Id: Ic8dabc2279117b7ff12eb75a9daa8d26c9d9bb25
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1592622
Commit-Queue: Abigail Klein <abigailbklein@google.com>
Auto-Submit: Abigail Klein <abigailbklein@google.com>
Reviewed-by: Avi Drissman <avi@chromium.org>
Reviewed-by: Elly Fong-Jones <ellyjones@chromium.org>
Cr-Commit-Position: refs/heads/master@{#659116}