Roll Skia from bdc3d3c60fa9 to d60c919fc866 (4 revisions)

https://skia.googlesource.com/skia.git/+log/bdc3d3c60fa9..d60c919fc866

2021-01-07 csmartdalton@google.com Revert "Move GrTriangulator internal struct definitions to the .h file"
2021-01-07 johnstiles@google.com Remove compile-time constant support from PrefixExpression.
2021-01-07 adlai@google.com Add a new implementation of reduceOpsTaskSplitting
2021-01-07 kjlubick@google.com [canvaskit] Add docs and example for flags

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 johnstiles@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: johnstiles@google.com
Change-Id: I8a9c6fbc2a78bc578a99a80812b72c30acb063ce
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2615958Reviewed-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@{#841198}

DEPS

@@ -199,7 +199,7 @@ 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': 'bdc3d3c60fa9ebb02e9c8f588050a824f3f73022',
+  'skia_revision': 'd60c919fc866fdb53ea532428a1a8b58b2309dc1',
   # Three lines of non-changing comments so that
   # the commit queue can handle CLs rolling V8
   # and whatever else without interference from each other.