Roll external/skia ee6b49b3af0b..73fcde07f808 (6 commits)

https://skia.googlesource.com/skia.git/+log/ee6b49b3af0b..73fcde07f808

2019-11-05 robertphillips@google.com Revert "Reland "Implement sample mask and sample locations support in Vulkan""
2019-11-05 robertphillips@google.com Revert "Add a "conservative raster" flag to GrPipeline and implement in Vulkan"
2019-11-05 bungeman@google.com Fix empty run handling in trivial shaper iterators
2019-11-05 fmalita@chromium.org [skottie] Streamlined gradient stop merger
2019-11-05 recipe-mega-autoroller@chops-service-accounts.iam.gserviceaccount.com Roll recipe dependencies (trivial).
2019-11-05 mtklein@google.com implement SkColorFilterShader::isOpaque()

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Change-Id: I37eeea61118eb50d081d8652f4a2ca2274b61c58
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