Cross-domain video loads do not prompt for authorization.

Cross-domain video loads do not prompt for authorization.
https://bugs.webkit.org/show_bug.cgi?id=159195
<rdar://problem/26234612>

Reviewed by Brent Fulgham.

Source/WebCore:

Test: http/tests/media/video-auth.html (modified)

We should prompt for authorization when a cross-origin <video> is embedded
in a web page.

* loader/MediaResourceLoader.cpp:
(WebCore::MediaResourceLoader::requestResource):

LayoutTests:

Add a cross-origin authorization sub-test.

* http/tests/media/video-auth.html:
* http/tests/media/video-auth-expected.txt:

git-svn-id: https://svn.webkit.org/repository/webkit/trunk@202579 268f45cc-cd09-0410-ab3c-d52691b4dbfc