Roll Skia from 9cb74e90792d to 81d4b5d5b45d (6 revisions) (flutter#31360

)

DEPS

@@ -27,7 +27,7 @@ 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': '9cb74e90792d641b8250a20f10492082d3a661ba',
+  'skia_revision': '81d4b5d5b45d8dfd547ecb314d31fc026a454cff',
 
   # WARNING: DO NOT EDIT canvaskit_cipd_instance MANUALLY
   # See `lib/web_ui/README.md` for how to roll CanvasKit to a new version.

ci/licenses_golden/licenses_skia

@@ -1,4 +1,4 @@
-Signature: 8e0b192c05f31c716c6751d6dc7dbff6
+Signature: 55f59a707b3a2d0113ab083bac21ee45
 
 UNUSED LICENSES:
 
@@ -2844,7 +2844,6 @@ FILE: ../../../third_party/skia/gm/textblobrandomfont.cpp
 FILE: ../../../third_party/skia/gm/textblobtransforms.cpp
 FILE: ../../../third_party/skia/gm/textblobuseaftergpufree.cpp
 FILE: ../../../third_party/skia/gm/transparency.cpp
-FILE: ../../../third_party/skia/gm/xform.cpp
 FILE: ../../../third_party/skia/include/codec/SkAndroidCodec.h
 FILE: ../../../third_party/skia/include/codec/SkCodec.h
 FILE: ../../../third_party/skia/include/core/SkEncodedImageFormat.h
@@ -5473,11 +5472,6 @@ FILE: ../../../third_party/skia/docs/examples/Xor.cpp
 FILE: ../../../third_party/skia/docs/examples/incomplete.cpp
 FILE: ../../../third_party/skia/experimental/minimal_ios_mtl_skia_app/main.mm
 FILE: ../../../third_party/skia/experimental/sktext/editor/App.cpp
-FILE: ../../../third_party/skia/experimental/xform/SkShape.cpp
-FILE: ../../../third_party/skia/experimental/xform/SkShape.h
-FILE: ../../../third_party/skia/experimental/xform/SkXform.cpp
-FILE: ../../../third_party/skia/experimental/xform/SkXform.h
-FILE: ../../../third_party/skia/experimental/xform/XContext.cpp
 FILE: ../../../third_party/skia/gm/crbug_918512.cpp
 FILE: ../../../third_party/skia/gm/fp_sample_chaining.cpp
 FILE: ../../../third_party/skia/gm/fpcoordinateoverride.cpp