This was a test for wkbug.com/87900: Add support for direction on table row group with collapsing borders, but changed behavior when fixing crbug.com/727173.
This test checks that a ltr table and a rtl row group (which should not affect cell ordering) properly compute its collapsing borders when the left-most cell's right border is 'hidden'.
For this test to pass, there should be only a rectangle with green borders.