Roll Skia from 270b5c04c234 to 71f12666647b (5 revisions)

https://skia.googlesource.com/skia.git/+log/270b5c04c234..71f12666647b

2020-10-28 mtklein@google.com Revert "SkPathView for ownerless (can live on stack) SkPaths"
2020-10-28 egdaniel@google.com Fix variable name in new uma macro.
2020-10-28 johnstiles@google.com Split the SkSL pool into small and large sections.
2020-10-28 fmalita@chromium.org [svg] Convert text-anchor to a presentation attribute
2020-10-28 tdenniston@google.com Add support for arc-length metric in variable width stroke sample

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 jcgregorio@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:1141332
Tbr: jcgregorio@google.com
Change-Id: Ibe8a16f0af07e493d5b2153fdce327b2b41b0439
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2506009Reviewed-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@{#821771}

DEPS

@@ -206,7 +206,7 @@ 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': '270b5c04c23440fdb1ed85f7fe70dbc64c39c6c0',
+  'skia_revision': '71f12666647b40c6d0a95ab75a5c77095a171e54',
   # Three lines of non-changing comments so that
   # the commit queue can handle CLs rolling V8
   # and whatever else without interference from each other.