Reviewed by David Levin.

        Remove the artificial -32px shift for media controls in mediaDocuments
        so that they overlap the canvas as they do in non-mediaDocuments.
        This also fixes test_shell failing to update the media slider (see
        linked crbug below).

        https://bugs.webkit.org/show_bug.cgi?id=27798
        http://crbug.com/72623

        Test: media/video-controls-in-media-document.html
        Added a render test that asserts that the controls show up in the
        expected spot (0,208) instead of below the canvas (0,240).

        * css/mediaControlsChromium.css:

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@78680 268f45cc-cd09-0410-ab3c-d52691b4dbfc