Bug 1111786 - Cherry-pick the skia 6f90475632b0ff8e9e83916ee6373d3c26cc9284 commit; r=upstream

Rewrite NaN checks in terms of SkScalarIsNaN()


We are trying to replace Skia's NaN checker with our own in Mozilla,
so it would be nice to have to patch a single place by making sure
these NaN checks used SkScalarIsNaN().
Bug 1111244 - Reorder the list of includes to shut up check_spidermonkey_style.py

Landed on a CLOSED TREE

--HG--
extra : amend_source : de2c4a84f13e64ab05e5dc18b4192d08b4ee38b5