Roll DevTools Frontend from ff509c5440f5 to 40fbf5738639 (2 revisions)

https://chromium.googlesource.com/devtools/devtools-frontend.git/+log/ff509c5440f5..40fbf5738639

2021-01-20 soxia@microsoft.com Service Worker Update Cycle Timeline
2021-01-20 tvanderlippe@chromium.org Put platform on the global scope in layout tests

If this roll has caused a breakage, revert this CL and stop the roller
using the controls here:
https://autoroll.skia.org/r/devtools-frontend-chromium
Please CC devtools-waterfall-sheriff-onduty@grotations.appspotmail.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

Bug: chromium:1050549,chromium:1066604
Tbr: devtools-waterfall-sheriff-onduty@grotations.appspotmail.com
Change-Id: I018ee80ed4a0982db93513735d6b8197ebd204d4
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2639520Reviewed-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@{#845302}

DEPS

@@ -278,7 +278,7 @@ vars = {
   # Three lines of non-changing comments so that
   # the commit queue can handle CLs rolling devtools-frontend
   # and whatever else without interference from each other.
-  'devtools_frontend_revision': 'ff509c5440f5259293218d59cf7ffc2417ca96a4',
+  'devtools_frontend_revision': '40fbf5738639c5f0043b73c8714d0a6b61f2bd59',
   # Three lines of non-changing comments so that
   # the commit queue can handle CLs rolling libprotobuf-mutator
   # and whatever else without interference from each other.