* floats-clear-multicol-balancing-*:
Change border-width from "normal" to "5px" so that the optimal column
height is 85px. This also makes those reftests renders the same across
all browsers since each browser renders "normal" differently.
* column-balancing-overflow-005:
This test is already wrong as its height is 13px/3 = 4.3333px, so it can
pass with some fuzzy. This patch makes the target column height
4px (including the children's overflow). This is the same as the `<p>`'s
height 4px in reference file.
* box-decoration-break-border-image:
Add 1px to .vbreak so that the optimal column balancing height is a
integer. Also, remove a whitespace between two `<span>` in `<pos2>` to make the
test more robust because the width of the whitespace is not an integer.
Differential Revision: https://phabricator.services.mozilla.com/D83729
