Roll external/skia 46b654df9..baf981f71 (1 commits)

https://skia.googlesource.com/skia.git/+log/46b654df9..baf981f71

2017-07-12 ethannicholas@google.com Revert "converted GrSimpleTextureEffect to sksl"

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Change-Id: Ia28f7e80cc0a8125fb0f790739f665096b1a9d30