[Gtk] Unskip the video track tests

[Gtk] Unskip the video track tests
https://bugs.webkit.org/show_bug.cgi?id=82590

Patch by Zan Dobersek <zandobersek@gmail.com> on 2012-04-06
Reviewed by Martin Robinson.

Source/WebCore:

Enable the video track runtime feature for the Gtk port as well.

No new tests - existing ones will be unskipped.

* bindings/generic/RuntimeEnabledFeatures.cpp:
(WebCore):

LayoutTests:

Unskip passing video track tests and update expectations
where necessary.

* platform/gtk/Skipped:
* platform/gtk/fast/dom/prototype-inheritance-2-expected.txt:

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@113446 268f45cc-cd09-0410-ab3c-d52691b4dbfc