[GStreamer] webkitwebsrc is exposed to application-side
https://bugs.webkit.org/show_bug.cgi?id=108088

Reviewed by Martin Robinson.

Switch the webkitwebsrc to handle webkit+http(s) uris so it is now
explicit that this element is meant to be used preferrably inside
WebKit. This change is internal to the player.

No new tests, covered by existing http/tests/media tests.

* platform/graphics/gstreamer/MediaPlayerPrivateGStreamer.cpp:
(WebCore::MediaPlayerPrivateGStreamer::setPlaybinURL):
(WebCore):
(WebCore::MediaPlayerPrivateGStreamer::load):
* platform/graphics/gstreamer/MediaPlayerPrivateGStreamer.h:
(MediaPlayerPrivateGStreamer):
* platform/graphics/gstreamer/WebKitWebSourceGStreamer.cpp:
(webKitWebSrcGetProtocols):
(webKitWebSrcSetUri):

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@141695 268f45cc-cd09-0410-ab3c-d52691b4dbfc