Roll src/third_party/skia b1b87d9df81e..a1e5630183c1 (10 commits) (#5637)

Auto-roller completed checks. Merging.

DEPS

@@ -23,7 +23,7 @@ vars = {
   'fuchsia_git': 'https://fuchsia.googlesource.com',
   'github_git': 'https://github.com',
   'skia_git': 'https://skia.googlesource.com',
-  'skia_revision': 'b1b87d9df81eb4ddb25fc76a2a2a6664fc4ef0ec',
+  'skia_revision': 'a1e5630183c1b0d5a7d6df53f30e026aedb2c539',
 
   # When updating the Dart revision, ensure that all entries that are
   # dependencies of Dart are also updated to match the entries in the

travis/licenses_golden/licenses_third_party

-Signature: bb93df10d0b6b7b727917f6b44fd7c60
+Signature: 6e6764dfa1de955bc41f3d2e2bf778b5
 
 UNUSED LICENSES:
 
@@ -17371,6 +17371,8 @@ FILE: ../../../third_party/skia/src/gpu/effects/GrUnpremulInputFragmentProcessor
 FILE: ../../../third_party/skia/src/gpu/effects/GrYUVtoRGBEffect.cpp
 FILE: ../../../third_party/skia/src/gpu/effects/GrYUVtoRGBEffect.fp
 FILE: ../../../third_party/skia/src/gpu/effects/GrYUVtoRGBEffect.h
+FILE: ../../../third_party/skia/src/gpu/mtl/GrMtlTextureRenderTarget.h
+FILE: ../../../third_party/skia/src/gpu/mtl/GrMtlTextureRenderTarget.mm
 FILE: ../../../third_party/skia/src/gpu/ops/GrClearStencilClipOp.cpp
 FILE: ../../../third_party/skia/src/gpu/ops/GrDebugMarkerOp.cpp
 FILE: ../../../third_party/skia/src/gpu/text/GrAtlasManager.cpp
@@ -19078,7 +19080,6 @@ FILE: ../../../third_party/skia/src/gpu/text/GrTextContext.cpp
 FILE: ../../../third_party/skia/src/gpu/text/GrTextContext.h
 FILE: ../../../third_party/skia/src/gpu/text/GrTextUtils.cpp
 FILE: ../../../third_party/skia/src/gpu/text/GrTextUtils.h
-FILE: ../../../third_party/skia/src/gpu/vk/GrVkBackendContext.cpp
 FILE: ../../../third_party/skia/src/gpu/vk/GrVkBuffer.cpp
 FILE: ../../../third_party/skia/src/gpu/vk/GrVkBuffer.h
 FILE: ../../../third_party/skia/src/gpu/vk/GrVkCaps.cpp