[chromium] media/track/track-cue-rendering.html fails

[chromium] media/track/track-cue-rendering.html fails
https://bugs.webkit.org/show_bug.cgi?id=75098

Reviewed by Dan Bernstein.

* media/media-controls.js:
(textTrackDisplayElement): Don't assume there is only one shadow DOM element used to
    display captions.
* media/track/track-cue-nothing-to-render-expected.txt: Updated.
* media/track/track-cue-nothing-to-render.html: Fix the test so it checks the track
    container and cue text pseudo element properties separately.
* media/track/track-cue-rendering-expected.txt: Updated for textTrackDisplayElement change.
* media/track/track-cue-rendering.html: Ditto.

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@103852 268f45cc-cd09-0410-ab3c-d52691b4dbfc