Tests a flag to make background shorthand property not override background-size when it's already set.

On success, you will see a series of "PASS" messages, followed by "TEST COMPLETE".


PASS e.style.background is 'url("dummy://test.png") center center / cover no-repeat border-box border-box red'
PASS e.style.backgroundSize is 'cover'

PASS successfullyParsed is true

TEST COMPLETE