BUG ID: Bugzilla bug 7916 Box repaint rect does not include the left overflow

STEPS TO TEST: Scroll and resize the window as necessary to bring the three test cases below into view. Press each Test button once. Do not scroll, resize, or hide the window or switch to another tab.

TEST PASS: In each test, “Lorem” will move down along with “ipsum”.

TEST FAIL: “Lorem” will stay behind as “ipsum” moves down.