Reviewed by Xan Lopez.

        [GTK] Pixel dumps do not include scrollbars in output images
        https://bugs.webkit.org/show_bug.cgi?id=53216

        Update expected results which should show scrollbars.

        * platform/gtk/css2.1/t0803-c5502-mrgn-r-02-c-expected.checksum:
        * platform/gtk/css2.1/t0803-c5502-mrgn-r-02-c-expected.png:
        * platform/gtk/css2.1/t0803-c5505-mrgn-02-c-expected.checksum:
        * platform/gtk/css2.1/t0803-c5505-mrgn-02-c-expected.png:
        * platform/gtk/css2.1/t080301-c411-vt-mrgn-00-b-expected.checksum:
        * platform/gtk/css2.1/t080301-c411-vt-mrgn-00-b-expected.png:
        * platform/gtk/css2.1/t0905-c5525-fltclr-00-c-ag-expected.checksum:
        * platform/gtk/css2.1/t0905-c5525-fltclr-00-c-ag-expected.png:
        * platform/gtk/css2.1/t0905-c5525-fltmrgn-00-c-ag-expected.checksum:
        * platform/gtk/css2.1/t0905-c5525-fltmrgn-00-c-ag-expected.png:
        * platform/gtk/css2.1/...