Roll Skia from 415642b766fa to b9a172aaef22 (3 revisions)

https://skia.googlesource.com/skia.git/+log/415642b766fa..b9a172aaef22

2020-12-18 skia-autoroll@skia-public.iam.gserviceaccount.com Roll SwiftShader from 1ca6504eb7bb to 1cc5b3357d2f (2 revisions)
2020-12-18 skia-autoroll@skia-public.iam.gserviceaccount.com Roll ANGLE from 909ea88b5e6d to de703db564d6 (5 revisions)
2020-12-18 skia-autoroll@skia-public.iam.gserviceaccount.com Roll Chromium from 09282fd5 to a51698b2 (491 revisions)

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 tdenniston@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: tdenniston@google.com
Test: Test: Test: BufferStorageTestES3.BufferStorageFlagsPersistentCoherentWrite
Change-Id: I1d770cc26ec1e1b052eab578ded446d5f9d709ac
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2597833Reviewed-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@{#838436}

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': '415642b766face3623257248e2c0f1d99d1406b2',
+  'skia_revision': 'b9a172aaef229207376501f54e94df1b7f2237aa',
   # Three lines of non-changing comments so that
   # the commit queue can handle CLs rolling V8
   # and whatever else without interference from each other.