Zero out GrSamplerState in constructor to recover performance loss on Linux from r4102. (Noise in padding bytes was breaking operator==()) Visual review by bsalomon@.
Zero out GrSamplerState in constructor to recover performance loss on Linux from r4102.
(Noise in padding bytes was breaking operator==())
Visual review by bsalomon@.



csulmone/skia,csulmone/skia,csulmone/skia,csulmone/skia