Roll Catapult from d84b21c3f04c to 6dacd170b8de (1 revision)

https://chromium.googlesource.com/catapult.git/+log/d84b21c3f04c..6dacd170b8de

2020-08-05 dproy@chromium.org trace-viewer: Add polyfill to systrace viewer

If this roll has caused a breakage, revert this CL and stop the roller
using the controls here:
https://autoroll.skia.org/r/catapult-autoroll
Please CC oysteine@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:chromeos-kevin-rel;luci.chromium.try:linux_optional_gpu_tests_rel;luci.chromium.try:mac_optional_gpu_tests_rel;luci.chromium.try:win_optional_gpu_tests_rel
Bug: chromium:1036492
Tbr: oysteine@google.com
Change-Id: Ica73c36ed38ff6dfd0b34a7788aaee0d5f56f1b4
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2339438Reviewed-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@{#795114}

DEPS

@@ -258,7 +258,7 @@ vars = {
   # Three lines of non-changing comments so that
   # the commit queue can handle CLs rolling catapult
   # and whatever else without interference from each other.
-  'catapult_revision': 'd84b21c3f04c3164609854d566514084bcca1da4',
+  'catapult_revision': '6dacd170b8de6d4a17d8b836d5f2f22c50e06154',
   # Three lines of non-changing comments so that
   # the commit queue can handle CLs rolling libFuzzer
   # and whatever else without interference from each other.