Roll external/skia baf981f71..5b8e2b899 (5 commits)
https://skia.googlesource.com/skia.git/+log/baf981f71..5b8e2b899
2017-07-12 fmalita@chromium.org Clarify adjustMatrixAndAppendStages semantics
2017-07-12 bsalomon@google.com Revert "Make DashOp a non-legacy GrMeshDrawOp."
2017-07-12 reed@google.com add guard for recent api change
2017-07-12 reed@google.com Revert "Revert "Change image encode api to return sk_sp""
2017-07-12 bsalomon@google.com Make DashOp a non-legacy GrMeshDrawOp.
Test: Presubmit checks will test this change.
Change-Id: Ie3954ec831ad1d7d821b01740b509e705c052cdb