This test checks to ensure that the window object is cleared during a navigation.
If the test passes, you will see only PASS messages below.
PASS: element 0 in the window's prototype chain was cleared
PASS: element 1 in the window's prototype chain was cleared
PASS: element 2 in the window's prototype chain was cleared
PASS: element 3 in the window's prototype chain was cleared
PASS: element 4 in the window's prototype chain was cleared