Roll Skia from 8d43858ed21a to 6a204db32c49 (7 revisions)

https://skia.googlesource.com/skia.git/+log/8d43858ed21a..6a204db32c49

2020-10-08 brianosman@google.com Change interface block's fVariable from ref to pointer
2020-10-08 ethannicholas@google.com moved SkSL Ternary data into IRNode
2020-10-08 ethannicholas@google.com moved SkSL If data into IRNode
2020-10-08 ethannicholas@google.com changed various SkSL structs into classes
2020-10-08 johnstiles@google.com Remove dedicated name from SymbolTable entries.
2020-10-08 robertphillips@google.com Add HW-filtered masks to thread-safe cache
2020-10-08 kjlubick@google.com [canvaskit] Update npm to 0.19.0

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 jvanverth@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: chromium:1108408
Tbr: jvanverth@google.com
Change-Id: Id23ccede5a1fe460e63b9ae8d452faa07300c1ee
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2461401Reviewed-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@{#815168}

DEPS

@@ -195,7 +195,7 @@ 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': '8d43858ed21a0a1b96f724f04eba510a2c44041f',
+  'skia_revision': '6a204db32c49af517bb475ee3ea07d06dce72203',
   # Three lines of non-changing comments so that
   # the commit queue can handle CLs rolling V8
   # and whatever else without interference from each other.