Roll src/third_party/dawn c15160f3ab08..dc9f1e680699 (1 commits)

https://dawn.googlesource.com/dawn.git/+log/c15160f3ab08..dc9f1e680699

git log c15160f3ab08..dc9f1e680699 --date=short --no-merges --format='%ad %ae %s'
2019-10-02 enga@chromium.org Add validation tests for WebGPU bind group "persistence"

Created with:
  gclient setdep -r src/third_party/dawn@dc9f1e680699

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
TBR=cwallez@google.com

Bug: None
Change-Id: Iadbfdfb47a6a82f5402e90a234ccdcb349e34bde
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1835063Reviewed-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@{#701925}

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': 'c15160f3ab08dcbb31adeac8490b394ed89a6d5b',
+  'dawn_revision': 'dc9f1e68069917f29d552d9cb0b7993fcb7c4059',
   # Three lines of non-changing comments so that
   # the commit queue can handle CLs rolling feed
   # and whatever else without interference from each other.