Roll src/third_party/dawn 93bea5cb50e3..e3f44e3cd6a1 (2 commits)

https://dawn.googlesource.com/dawn.git/+log/93bea5cb50e3..e3f44e3cd6a1

git log 93bea5cb50e3..e3f44e3cd6a1 --date=short --first-parent --format='%ad %ae %s'
2020-04-15 cwallez@chromium.org ShutDownBase, only tick frontend facilities if they have been created
2020-04-15 cwallez@chromium.org Null: Properly fake commands being completed on WaitForIdle

Created with:
  gclient setdep -r src/third_party/dawn@e3f44e3cd6a1

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 cwallez@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/+/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:1068465,chromium:1068886,chromium:1068887
Tbr: cwallez@google.com
Change-Id: I22df67e28904c6733db151505b5bd93cac800e0a
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2150420Reviewed-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@{#759228}

DEPS

@@ -302,7 +302,7 @@ 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': '93bea5cb50e30f115088be752145df88562bfa25',
+  'dawn_revision': 'e3f44e3cd6a1ab416d5e7b64b09c3c08c935a911',
   # Three lines of non-changing comments so that
   # the commit queue can handle CLs rolling feed
   # and whatever else without interference from each other.