WebProcess spins beneath [QTMovie movieFileTypes:]

WebProcess spins beneath [QTMovie movieFileTypes:]
https://bugs.webkit.org/show_bug.cgi?id=81133

Reviewed by Eric Carlson.

No new tests; speculative fix for top WebProcess spin.

When checking to see if a given mime type is supported by QuickTime,
immediately exclude all types that do not begin with 'audio/' or 'video/'.
* platform/graphics/mac/MediaPlayerPrivateQTKit.mm:
(WebCore::MediaPlayerPrivateQTKit::supportsType):

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@110727 268f45cc-cd09-0410-ab3c-d52691b4dbfc