Roll DevTools Frontend from 405b7b290354 to 2f29f1b55a5b (4 revisions)

https://chromium.googlesource.com/devtools/devtools-frontend.git/+log/405b7b290354..2f29f1b55a5b

2021-08-27 alexrudenko@chromium.org Remove FixedColor metric
2021-08-27 sigurds@chromium.org Improve Timing reporting for server-delayed requests
2021-08-27 kprokopenko@chromium.org Use type-safe events for NetworkProject
2021-08-27 devtools-ci-autoroll-builder@chops-service-accounts.iam.gserviceaccount.com Update DevTools Chromium DEPS.

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 file a bug in Chromium: https://bugs.chromium.org/p/chromium/issues/entry

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/main/autoroll/README.md

Bug: chromium:1228674,chromium:1231524,chromium:1242479
Tbr: devtools-waterfall-sheriff-onduty@grotations.appspotmail.com
Change-Id: I8db893b4be0c7ce7227b70ab04b2b0d2f2477b4e
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/3124002
Commit-Queue: chromium-autoroll <chromium-autoroll@skia-public.iam.gserviceaccount.com>
Bot-Commit: chromium-autoroll <chromium-autoroll@skia-public.iam.gserviceaccount.com>
Cr-Commit-Position: refs/heads/main@{#915907}