Roll src/third_party/skia 32803ff..6863bb0 (7 commits) (#13318)

https://skia.googlesource.com/skia.git/+log/32803ff74448..6863bb0930cf

git log 32803ff..6863bb0 --date=short --no-merges --format='%ad %ae %s'
2019-10-23 jvanverth@google.com Set Metal rendertargetproxy via drawableSize
2019-10-23 senorblanco@chromium.org Dawn: implement unified UBOs.
2019-10-23 michaelludwig@google.com Revert "hide color filters from blitters"
2019-10-23 mtklein@google.com hide color filters from blitters
2019-10-23 bsalomon@google.com Rewrite ReadPixels_Gpu test to be more exhaustive and share code.
2019-10-23 robertphillips@google.com Rename *worstCase* to backingStore* in GrSurfaceProxy
2019-10-23 fmalita@chromium.org GPU support for SkColorFilters::HSLAMatrix

Created with:
  gclient setdep -r src/third_party/skia@6863bb0930cf

If this roll has caused a breakage, revert this CL and stop the roller
using the controls here:
https://autoroll.skia.org/r/skia-flutter-autoroll
Please CC michaelludwig@google.com on the revert to ensure that a human
is aware of the problem.

To report a problem with the AutoRoller itself, please file a bug:
https://bugs.chromium.org/p/skia/issues/entry?template=Autoroller+Bug

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

Bug: None
TBR=michaelludwig@google.com

Author: skia-flutter-autoroll

DEPS

@@ -26,7 +26,7 @@ vars = {
   'skia_git': 'https://skia.googlesource.com',
   # OCMock is for testing only so there is no google clone
   'ocmock_git': 'https://github.com/erikdoe/ocmock.git',
-  'skia_revision': '32803ff7444854c109d1a751a2f240812aca0d29',
+  'skia_revision': '6863bb0930cf5e31322585c49460a01e057c16e9',
 
   # When updating the Dart revision, ensure that all entries that are
   # dependencies of Dart are also updated to match the entries in the

ci/licenses_golden/licenses_skia

@@ -1,4 +1,4 @@
-Signature: 7a58a7e8b60f1b1e69ae079305b161c1
+Signature: e91c49302698328fa1e7e4b79acc4850
 
 UNUSED LICENSES:
 
@@ -3841,9 +3841,15 @@ FILE: ../../../third_party/skia/src/gpu/GrUtil.h
 FILE: ../../../third_party/skia/src/gpu/GrWaitRenderTask.cpp
 FILE: ../../../third_party/skia/src/gpu/GrWaitRenderTask.h
 FILE: ../../../third_party/skia/src/gpu/effects/GrColorMatrixFragmentProcessor.fp
+FILE: ../../../third_party/skia/src/gpu/effects/GrHSLToRGBFilterEffect.fp
+FILE: ../../../third_party/skia/src/gpu/effects/GrRGBToHSLFilterEffect.fp
 FILE: ../../../third_party/skia/src/gpu/effects/GrSaturateProcessor.fp
 FILE: ../../../third_party/skia/src/gpu/effects/generated/GrColorMatrixFragmentProcessor.cpp
 FILE: ../../../third_party/skia/src/gpu/effects/generated/GrColorMatrixFragmentProcessor.h
+FILE: ../../../third_party/skia/src/gpu/effects/generated/GrHSLToRGBFilterEffect.cpp
+FILE: ../../../third_party/skia/src/gpu/effects/generated/GrHSLToRGBFilterEffect.h
+FILE: ../../../third_party/skia/src/gpu/effects/generated/GrRGBToHSLFilterEffect.cpp
+FILE: ../../../third_party/skia/src/gpu/effects/generated/GrRGBToHSLFilterEffect.h
 FILE: ../../../third_party/skia/src/gpu/effects/generated/GrSaturateProcessor.cpp
 FILE: ../../../third_party/skia/src/gpu/effects/generated/GrSaturateProcessor.h
 FILE: ../../../third_party/skia/src/gpu/geometry/GrQuadBuffer.h