Roll Skia from a909dd6b8d8d to 8b85d7b429d1 (5 revisions)

https://skia.googlesource.com/skia.git/+log/a909dd6b8d8d..8b85d7b429d1

2021-09-24 jvanverth@google.com Graphite: add ResourceProvider and CommandBuffer stubs
2021-09-24 michaelludwig@google.com Implement separate crop filter
2021-09-24 johnstiles@google.com Fix for fuzzer-discovered error with invalid var-initializers.
2021-09-24 brianosman@google.com Remove all clamping to "valid" premultiplied colors
2021-09-24 fmalita@chromium.org Scale picture shader (GPU) by input alpha

If this roll has caused a breakage, revert this CL and stop the roller
using the controls here:
https://skia-autoroll.corp.goog/r/android-master-autoroll
Please CC scroggo@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/main/autoroll/README.md

Test: Presubmit checks will test this change.
Exempt-From-Owner-Approval: The autoroll bot does not require owner approval.
Bug: b/186777432
Change-Id: I367c473a0758899c7fb40107cd79587211d230c4