Roll Skia from 5b589fd27351 to 4c6f57a23e63 (3 revisions)

https://skia.googlesource.com/skia.git/+log/5b589fd27351..4c6f57a23e63

2020-11-30 tdenniston@google.com [svg] Use new code path for rest of presentation attrs
2020-11-30 bsalomon@google.com Remove GrRenderTargetContextPriv and GrSurfaceContextPriv
2020-11-30 reed@google.com move SkMipmapBuilder to private

If this roll has caused a breakage, revert this CL and stop the roller
using the controls here:
https://autoroll.skia.org/r/skia-autoroll
Please CC westont@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

Cq-Include-Trybots: luci.chromium.try:android_optional_gpu_tests_rel;luci.chromium.try:linux-blink-rel;luci.chromium.try:linux-chromeos-compile-dbg;luci.chromium.try:linux_optional_gpu_tests_rel;luci.chromium.try:mac_optional_gpu_tests_rel;luci.chromium.try:win_optional_gpu_tests_rel
Cq-Do-Not-Cancel-Tryjobs: true
Bug: None
Tbr: westont@google.com
Change-Id: I6eb02db08d9b1182a6414bf4ad849dbb520ee159
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2566650Reviewed-by: chromium-autoroll <chromium-autoroll@skia-public.iam.gserviceaccount.com>
Commit-Queue: chromium-autoroll <chromium-autoroll@skia-public.iam.gserviceaccount.com>
Cr-Commit-Position: refs/heads/master@{#832125}

DEPS

@@ -200,7 +200,7 @@ vars = {
   # Three lines of non-changing comments so that
   # the commit queue can handle CLs rolling Skia
   # and whatever else without interference from each other.
-  'skia_revision': '5b589fd273516c38c7d00c81bdbaedcc7ab4db3f',
+  'skia_revision': '4c6f57a23e63d9a3ab0509798ce3adbbf10e03ec',
   # Three lines of non-changing comments so that
   # the commit queue can handle CLs rolling V8
   # and whatever else without interference from each other.