This test checks that moving an element with an event handler from one window (FrameHost) to another properly migrates the handler too.
On success, you will see a series of "PASS" messages, followed by "TEST COMPLETE".
PASS internals.scrollEventHandlerCount(document) is 0
PASS internals.scrollEventHandlerCount(document) is 1
PASS successfullyParsed is true
TEST COMPLETE