Roll Skia from fe3d9a23095e to 1748c6a3b8c8 (4 revisions)

https://skia.googlesource.com/skia.git/+log/fe3d9a23095e..1748c6a3b8c8

2020-09-25 skia-autoroll@skia-public.iam.gserviceaccount.com Roll SwiftShader from a09406249fa3 to b94db86cf9b3 (1 revision)
2020-09-25 skia-autoroll@skia-public.iam.gserviceaccount.com Roll dawn from 75e5ed6161fc to eec9edfd5769 (3 revisions)
2020-09-25 brianosman@google.com Change VariableReference::fVariable to a pointer
2020-09-24 robertphillips@google.com Reduce needless spread of GrNonAtomicRef.h

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 csmartdalton@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: csmartdalton@google.com
Change-Id: I7e379e66aeaebff208ec0ea70367ede57adf7775
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2430651Reviewed-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@{#810659}

DEPS

@@ -195,7 +195,7 @@ 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': 'fe3d9a23095ece58faf11e6013ed25913536d095',
+  'skia_revision': '1748c6a3b8c865a5fc7c22687fe34f3cafd563fa',
   # Three lines of non-changing comments so that
   # the commit queue can handle CLs rolling V8
   # and whatever else without interference from each other.