Shadow DOM: Slots and fallback contents

Test passes if there are two lines of text "B", "A" below.

B

A

Test passes if there are two lines of text "D", "C" below.

D

C

Test passes if there are two lines of text "F", "E" below.

F

E

Test passes if there is one line of text "SLOT4" below.

SLOT4

Test passes if there is one line of text "SLOT5" below.

SLOT5