Roll Skia from 98b928fcfad7 to dffd20efe95c (6 revisions)

https://skia.googlesource.com/skia.git/+log/98b928fcfad7..dffd20efe95c

2020-11-02 kjlubick@google.com [canvaskit] Add unit tests to wasm_gm_tests
2020-11-02 csmartdalton@google.com Fix Wang's formula for cubics
2020-11-02 johnstiles@google.com Revert "heif: Add AVIF type and AVIF sniffing"
2020-11-02 vigneshv@google.com heif: Add AVIF type and AVIF sniffing
2020-11-02 johnstiles@google.com Split Texture test into separate 1D and 2D tests.
2020-11-02 robertphillips@google.com Add callback to thread-safe cache to resolve vertexData collisions

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 bsalomon@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:1108408
Tbr: bsalomon@google.com
Change-Id: Ifd340bf5099bdfaf3a22a6bf1f95044e238ded68
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2513799Reviewed-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@{#823257}

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': '98b928fcfad7ddc772d5a053027fd226da57e77f',
+  'skia_revision': 'dffd20efe95cfa6c4d928c9091c99825ab7b4a3c',
   # Three lines of non-changing comments so that
   # the commit queue can handle CLs rolling V8
   # and whatever else without interference from each other.