Test that background position values do not leak between layers

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


PASS bgPosLayers[0].search("-10px") is >= 0
PASS bgPosLayers[0].search("50px") is >= 0
PASS bgPosLayers[1].search("-10px") is -1
PASS bgPosLayers[1].search("50px") is -1
PASS successfullyParsed is true

TEST COMPLETE