https://github.com/angular/angular.js/blob/64fd2c421ed582c16812d164a8a6f031b8e66287/src/jqLite.js#L433

It looks like `HTMLElement.style` can't be trusted on IE prior to IE9, which may be why the tests on Travis are seeing an empty array, rather than actual prop names. Not totally sure about this, though. Still, it is seeing `undefined`, which is not great.