Roll Skia from 8a166f3bc757 to 6940cff9c3e7 (2 revisions)

https://skia.googlesource.com/skia.git/+log/8a166f3bc757..6940cff9c3e7

2021-07-23 jcgregorio@google.com Revert "Roll recipe dependencies (nontrivial)."
2021-07-23 jcgregorio@google.com Revert "Roll recipe dependencies (trivial)."

If this roll has caused a breakage, revert this CL and stop the roller
using the controls here:
https://autoroll.skia.org/r/skia-skiabot-test-autoroll
Please CC borenet@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

Tbr: borenet@google.com
Change-Id: I1e423899c98d02cdb395f592050921311a3d8829
Reviewed-on: https://skia-review.googlesource.com/c/skiabot-test/+/431777
Reviewed-by: skia-autoroll <skia-autoroll@skia-public.iam.gserviceaccount.com>
Commit-Queue: skia-autoroll <skia-autoroll@skia-public.iam.gserviceaccount.com>
diff --git a/DEPS b/DEPS
index 26dd9d6..298482a 100644
--- a/DEPS
+++ b/DEPS
@@ -3,7 +3,7 @@
   # 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': '8a166f3bc75766bd22b05524f0d976579b4e4900',
+  'skia_revision': '6940cff9c3e784fc8af44994059dbf32427d8c5a',
   # Three lines of non-changing comments so that
   # the commit queue can handle CLs rolling Skia
   # and whatever else without interference from each other.