Roll external/skia 907783bb7..ee6aa80e8 (7 commits)
https://skia.googlesource.com/skia.git/+log/907783bb7..ee6aa80e8
2017-07-13 brianosman@google.com New zero length path GM
2017-07-13 reed@google.com Revert "Revert "Experimental blur code with 32 bit fix.""
2017-07-13 bsalomon@google.com Give GrSimpleMeshDrawOpHelper a cpp file
2017-07-13 ethannicholas@google.com SPIR-V support for more integer operations
2017-07-13 bsalomon@google.com Fix two issues in DashOp
2017-07-13 bsalomon@google.com Make ShadowRRectOp a non-legacy GrMeshDrawOp
2017-07-13 bsalomon@google.com Fail to make render target context if GrContext is abandoned
Test: Presubmit checks will test this change.
Change-Id: Ic945e48dc7c44cfa8941cd33103d7857f4fb8856