1 Verifies that dragging mouse in/out of an element doesn't fire redundant mouseenter or mouseleave events (crbug.com/470258)
3 On success, you will see a series of "PASS" messages, followed by "TEST COMPLETE".
6 outer received mouseenter
7 PASS wasInside['outer'] is false
8 outer received mousedown
9 inner received mouseenter
10 PASS wasInside['inner'] is false
11 inner received mouseleave
12 PASS wasInside['inner'] is true
13 outer received mouseup
14 outer received mouseleave
15 PASS wasInside['outer'] is true
16 PASS successfullyParsed is true