Reviewed by Simon Fraser.

        Support background-clip: content-box
        https://bugs.webkit.org/show_bug.cgi?id=48771

        Addded content-box as a valid background-clip value.

        * WebCore/css/CSSParser.cpp:
        (WebCore::parseBackgroundClip):
2011-01-18  Krithigassree Sambamurthy  <krithigassree.sambamurthy@nokia.com>

        Reviewed by Simon Fraser.

        Support background-clip: content-box
        https://bugs.webkit.org/show_bug.cgi?id=48771

        Added test cases to check the various valid background-clip values.

        * fast/css/background-clip-text-expected.txt:
        * fast/css/background-clip-values-expected.checksum: Added.
        * fast/css/background-clip-values-expected.txt: Added.
        * fast/css/background-clip-values.html: Added.
        * fast/css/script-tests/background-clip-text.js:

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@76047 268f45cc-cd09-0410-ab3c-d52691b4dbfc