Don't drop 1px rects for FocusableNodes if all we have is 1px rects

This avoids returning a null boundingRect unless we absolutely have to.

Bug: 70768
Change-Id: I06fbc1191ba567774691e755c5e071e049cf07e9
Merge "Don't drop 1px rects for FocusableNodes if all we have is 1px rects"