Roll DevTools Frontend from 256b2c258767 to c9e3d3e3a7e0 (6 revisions)

https://chromium.googlesource.com/devtools/devtools-frontend.git/+log/256b2c258767..c9e3d3e3a7e0

2020-10-05 pfaffe@chromium.org Implement support for the JavaScript formatter API
2020-10-05 sigurds@chromium.org Prepare for removal of isScrolledToBottom from Element's prototype
2020-10-05 tvanderlippe@chromium.org Typecheck sources/SourcesView.js with TypeScript
2020-10-05 bmeurer@chromium.org Fix accidentally inversed experiment.
2020-10-05 yangguo@chromium.org [ts] Type-check har_importer/HARFormat.js with TypeScript
2020-10-05 bmeurer@chromium.org [ts] Type-check worker_main/WorkerMain.js with TypeScript

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:1011811,chromium:1128416,chromium:1135143
Tbr: devtools-waterfall-sheriff-onduty@grotations.appspotmail.com
Change-Id: I9b23e31a76d9a4b3034134e9c0af2c18392668a0
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2450869Reviewed-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@{#813886}

DEPS

@@ -266,7 +266,7 @@ 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': '256b2c2587679c74a8fbdaeb9d0b1601c22e889f',
+  'devtools_frontend_revision': 'c9e3d3e3a7e06e18fec7ef2599c397ecbbefa0da',
   # 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.