Roll external/skia 442155056..4f94ef6cb (20 commits)

https://skia.googlesource.com/skia.git/+log/442155056..4f94ef6cb

2018-09-12 michaelludwig@google.com Reland "Base Gradient FP Refactor"
2018-09-12 swiftshader-skia-autoroll@skia-buildbots.google.com.iam.gserviceaccount.com Roll third_party/externals/swiftshader fe79649598fb..d7a21ccd41ce (1 commits)
2018-09-12 fmalita@chromium.org Improved SkPath packing
2018-09-12 borenet@google.com [infra] Update recipe deps, fix usage of bot_update
2018-09-12 caryclark@skia.org Revert "remove SK_SUPPORT_LEGACY_TYPEFACE_MAKEFROMSTREAM"
2018-09-12 jcgregorio@google.com Fix container builder command line.
2018-09-12 mtklein@google.com revise p3 GM
2018-09-12 brianosman@google.com Add F16 test-case to all_bitmap_configs
2018-09-12 robertphillips@google.com Expand SkPath fuzzer
2018-09-12 halcanary@google.com SkPDF: do all rasterScale calculations in one place.
2018-09-12 fmalita@chromium.org [sksg] Trim down sksg::Matrix size
2018-09-12 reed@google.com remove SK_SUPPORT_LEGACY_TYPEFACE_MAKEFROMSTREAM
2018-09-12 brianosman@google.com Remove raw-data version of createTextureProxy
2018-09-12 reed@google.com allow path.add(path) safely
2018-09-12 egdaniel@google.com Add unit test to test basic importing and drawing of AHardwareBuffers.
2018-09-12 reed@google.com change language for pathkit
2018-09-12 brianosman@google.com Revert "Revert "Add Adreno workaround for MSAA + stencil + ReadPixels""
2018-09-12 pcc@google.com SkRemoteGlyphCache: Make serialization code bitness agnostic.
2018-09-12 robertphillips@google.com Loosen up assert in SkImage_Gpu::asTextureProxyRef
2018-09-12 brianosman@google.com Revert "Add Adreno workaround for MSAA + stencil + ReadPixels"

The AutoRoll server is located here: https://autoroll-internal.skia.org/r/android-master-autoroll

Documentation for the AutoRoller is here:
https://skia.googlesource.com/buildbot/+/master/autoroll/README.md

If the roll is causing failures, please contact the current sheriff, who should
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Test: Presubmit checks will test this change.
Change-Id: Ibb2c7f0f4ff315c4080170ed432aa4bb9676b493
Exempt-From-Owner-Approval: The autoroll bot does not require owner approval.