[Mac] "automatic" track selection should only select a track that matches user language
https://bugs.webkit.org/show_bug.cgi?id=114976

Reviewed by Jer Noble.

Source/WebCore:

Test: media/track/track-automatic-subtitles.html

* page/CaptionUserPreferencesMac.mm:
(WebCore::CaptionUserPreferencesMac::textTrackSelectionScore): When in "automatic" mode, only
    consider text tracks that match the user's preferred language when the primary audio track
    does not.

LayoutTests:

* media/track/track-automatic-subtitles-expected.txt: Added.
* media/track/track-automatic-subtitles.html: Added.
* platform/mac/TestExpectations: Skip track-user-preferences.html, the logic is no longer
     correct for the Mac port.


git-svn-id: http://svn.webkit.org/repository/webkit/trunk@148907 268f45cc-cd09-0410-ab3c-d52691b4dbfc