Two days ago, TestSwarm updated the jquery-core browser set from Chrome 43/44 to Chrome 44/45.

This revealed a test failure.

http://swarm.jquery.org/result/619430:

offset: fractions (see #7730 and #7885) (1, 1, 2)
Check top
Expected: 1000
Result: 999.984375

Looks like Chrome 45 is more precise than our tests expect.