Roll src/third_party/skia 3517aa7b14ad..826484f2631f (18 commits) (flutter#14375)

https://skia.googlesource.com/skia.git/+log/3517aa7b14ad..826484f2631f

git log 3517aa7b14ad..826484f2631f --date=short --first-parent --format='%ad %ae %s'
2019-12-12 egdaniel@google.com Always report SkImage_Gpu subclasses as being texture backed.
2019-12-12 egdaniel@google.com Revert "When converting runtime SkSL to FP SkSL, use default settings"
2019-12-12 recipe-mega-autoroller@chops-service-accounts.iam.gserviceaccount.com Roll recipe dependencies (trivial).
2019-12-11 brianosman@google.com When converting runtime SkSL to FP SkSL, use default settings
2019-12-11 egdaniel@google.com Update FragmentProcessor TextureSampler to hold an GrSurfaceProxyView.
2019-12-11 jvanverth@google.com Change PerspectiveClip to clip directly to half plane.
2019-12-11 jvanverth@google.com Adjust cache key for Metal persistent cache.
2019-12-11 skia-autoroll@skia-public.iam.gserviceaccount.com Roll skia/third_party/skcms ef3043bd8110..64374756e037 (1 commits)
2019-12-11 nifong@google.com Fix audit trail visualization bugs
2019-12-11 fmalita@chromium.org [skottie] Invert effect support
2019-12-11 halcanary@google.com experimental/skottie_ios/SkottieUiView
2019-12-11 csmartdalton@google.com Suppress allocation warnings for tests that induce them intentionally
2019-12-11 mtklein@google.com add SK_CPU_LIMIT_AVX
2019-12-11 halcanary@google.com public.bzl: add metal_objc_srcs()
2019-12-11 fmalita@chromium.org [skottie] Add SkottieSlide frame rate UI option
2019-12-11 halcanary@google.com Roll third_party/externals/libgifcodec ed218be1..38d9c73f (2 commits)
2019-12-11 herb@google.com Remove unused buffer call for SkGlyphRunPaint
2019-12-11 mtklein@google.com roll clang to 9.0

Created with:
  gclient setdep -r src/third_party/skia@826484f2631f

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 djsollen@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: djsollen@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': '3517aa7b14ad52aa662bf38932f2ba358a9f8318',
+  'skia_revision': '826484f2631ff2249da4779ae60947effebd564a',
 
   # 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: 6bffa87a7c5c059414f1658dd2762fdf
+Signature: 1e3c9c336a7abcf29e6b685726fa4f0e
 
 UNUSED LICENSES:
 
@@ -3101,6 +3101,7 @@ FILE: ../../../third_party/skia/modules/skottie/src/effects/FillEffect.cpp
 FILE: ../../../third_party/skia/modules/skottie/src/effects/GaussianBlurEffect.cpp
 FILE: ../../../third_party/skia/modules/skottie/src/effects/GradientEffect.cpp
 FILE: ../../../third_party/skia/modules/skottie/src/effects/HueSaturationEffect.cpp
+FILE: ../../../third_party/skia/modules/skottie/src/effects/InvertEffect.cpp
 FILE: ../../../third_party/skia/modules/skottie/src/effects/LevelsEffect.cpp
 FILE: ../../../third_party/skia/modules/skottie/src/effects/LinearWipeEffect.cpp
 FILE: ../../../third_party/skia/modules/skottie/src/effects/MotionBlurEffect.cpp
@@ -5040,10 +5041,14 @@ FILE: ../../../third_party/skia/docs/examples/Typeface_Methods.cpp
 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/skottie_ios/SkAnimationDraw.h
 FILE: ../../../third_party/skia/experimental/skottie_ios/SkMetalViewBridge.h
 FILE: ../../../third_party/skia/experimental/skottie_ios/SkMetalViewBridge.mm
+FILE: ../../../third_party/skia/experimental/skottie_ios/SkTimeKeeper.h
 FILE: ../../../third_party/skia/experimental/skottie_ios/SkottieMtkView.h
 FILE: ../../../third_party/skia/experimental/skottie_ios/SkottieMtkView.mm
+FILE: ../../../third_party/skia/experimental/skottie_ios/SkottieUIView.h
+FILE: ../../../third_party/skia/experimental/skottie_ios/SkottieUIView.mm
 FILE: ../../../third_party/skia/experimental/skottie_ios/main.mm
 FILE: ../../../third_party/skia/experimental/xform/SkShape.cpp
 FILE: ../../../third_party/skia/experimental/xform/SkShape.h