Comment 4 for bug 1434193

This shouldn't be an issue just in trunk - it should be there in 1.5 as well because it's due to the fix for bug 1402975 (at least, I think it is).

Basically, when running on mobile we set a layout viewport with of 960px for pages that don't have a viewport meta tag so that desktop sites are laid out better (this is the same as Chrome/Android). The issue with the test is that it creates an absolute positioned element which is positioned relative to the layout viewport, and the layout viewport != device viewport. This is the expected behaviour