Roll Skia from 21bbfc6c2dfe to 30212b7941d6 (6 revisions) (#19009)

https://skia.googlesource.com/skia.git/+log/21bbfc6c2dfe..30212b7941d6

2020-06-11 johnstiles@google.com Fix implicit fallthroughs throughout Skia.
2020-06-11 ethannicholas@google.com Revert "fixed sample(..., matrix) with runtime effects"
2020-06-11 reed@google.com Add filter-quality to imageshader factory
2020-06-11 csmartdalton@google.com Duplicate ccpr/GrCCStrokeGeometry to tessellate/GrStrokeGeometry
2020-06-11 reed@google.com remove unneeded SK_LEGACY_BLITTER_CHOICE flag
2020-06-11 robertphillips@google.com Add new GM to exercise Vulkan YCbCr images

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 bungeman@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/+doc/master/autoroll/README.md

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': '21bbfc6c2dfe07f0406df3dcce4eddd160db92b7',
+  'skia_revision': '30212b7941d6aa3b50978bac103f3c5b1b8cd20a',
 
   # 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

-Signature: cfdd5bbe0473ca5d32a6dea2b2b55e27
+Signature: 1627ef956dbb3f190d56cedf42ae5d78
 
 UNUSED LICENSES:
 
@@ -3493,6 +3493,8 @@ FILE: ../../../third_party/skia/src/gpu/ops/GrQuadPerEdgeAA.cpp
 FILE: ../../../third_party/skia/src/gpu/ops/GrQuadPerEdgeAA.h
 FILE: ../../../third_party/skia/src/gpu/ops/GrStrokeRectOp.cpp
 FILE: ../../../third_party/skia/src/gpu/ops/GrStrokeRectOp.h
+FILE: ../../../third_party/skia/src/gpu/tessellate/GrStrokeGeometry.cpp
+FILE: ../../../third_party/skia/src/gpu/tessellate/GrStrokeGeometry.h
 FILE: ../../../third_party/skia/src/gpu/text/GrAtlasManager.cpp
 FILE: ../../../third_party/skia/src/gpu/text/GrAtlasManager.h
 FILE: ../../../third_party/skia/src/gpu/text/GrSDFMaskFilter.cpp
@@ -3900,6 +3902,7 @@ FILE: ../../../third_party/skia/gm/crbug_1041204.cpp
 FILE: ../../../third_party/skia/gm/crbug_224618.cpp
 FILE: ../../../third_party/skia/gm/encode_color_types.cpp
 FILE: ../../../third_party/skia/gm/userfont.cpp
+FILE: ../../../third_party/skia/gm/ycbcrimage.cpp
 FILE: ../../../third_party/skia/include/gpu/GrBackendSurfaceMutableState.h
 FILE: ../../../third_party/skia/include/gpu/d3d/GrD3DBackendContext.h
 FILE: ../../../third_party/skia/include/gpu/d3d/GrD3DTypes.h