Roll src/third_party/skia 2c5b856a7f09..b1e9971eb712 (3 commits)

https://skia.googlesource.com/skia.git/+log/2c5b856a7f09..b1e9971eb712

git log 2c5b856a7f09..b1e9971eb712 --date=short --first-parent --format='%ad %ae %s'
2020-01-27 brianosman@google.com Switch runtime SkSL to always sample at explicit coords
2020-01-27 sergeyu@google.com Fix GrSmallPathRenderer to respect max texture size.
2020-01-27 kjlubick@google.com [canvaskit] Fix test for drawOnce

Created with:
  gclient setdep -r src/third_party/skia@b1e9971eb712

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 reed@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/+/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
Bug: None
Tbr: reed@google.com
Change-Id: Ic888343ead714d0dca80f0a603993d6d7293f4f9
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2022967Reviewed-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@{#735439}

DEPS

@@ -181,7 +181,7 @@ 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': '2c5b856a7f098d01d59b965b0f11705d0d624e01',
+  'skia_revision': 'b1e9971eb7126d29468c42d6fa74fb8a3cfca5bd',
   # Three lines of non-changing comments so that
   # the commit queue can handle CLs rolling V8
   # and whatever else without interference from each other.