Roll Dawn from c120b02dbe14 to 200941c79751 (2 revisions)

https://dawn.googlesource.com/dawn.git/+log/c120b02dbe14..200941c79751

2021-01-05 enga@chromium.org dawn_wire: Return early in callbacks after the server is destroyed
2021-01-05 enga@chromium.org Use a common helper for std::nothrow

If this roll has caused a breakage, revert this CL and stop the roller
using the controls here:
https://autoroll.skia.org/r/dawn-chromium-autoroll
Please CC enga@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:dawn-linux-x64-deps-rel;luci.chromium.try:dawn-mac-x64-deps-rel;luci.chromium.try:dawn-win10-x64-deps-rel;luci.chromium.try:dawn-win10-x86-deps-rel
Bug: chromium:1147416,chromium:1161943
Tbr: enga@google.com
Change-Id: Ieca735f8f5f5ddf478ec35a7d8ad6570e8426dd2
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2610805Reviewed-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@{#840157}

DEPS

@@ -314,7 +314,7 @@ vars = {
   # Three lines of non-changing comments so that
   # the commit queue can handle CLs rolling feed
   # and whatever else without interference from each other.
-  'dawn_revision': 'c120b02dbe147b4cfdfabc55b7c63808e662bf05',
+  'dawn_revision': '200941c797512895039e9f0315fc18fd9d9734ad',
   # Three lines of non-changing comments so that
   # the commit queue can handle CLs rolling feed
   # and whatever else without interference from each other.