Roll DevTools Frontend from d4a7e12496b5 to 6ec121d8c3d5 (9 revisions)

https://chromium.googlesource.com/devtools/devtools-frontend.git/+log/d4a7e12496b5..6ec121d8c3d5

2020-08-28 tvanderlippe@chromium.org Fix URL flickering in image preview pane
2020-08-28 tvanderlippe@chromium.org Remove is_legacy_javascript_entrypoint
2020-08-28 devtools-ci-autoroll-builder@chops-service-accounts.iam.gserviceaccount.com Update DevTools DEPS.
2020-08-28 tvanderlippe@chromium.org Fix focus ring for TBT link
2020-08-28 wolfi@chromium.org Fix pie chart backgound color on dark theme
2020-08-28 tvanderlippe@chromium.org Typecheck persistence/IsolatedFileSystem.js with TypeScript
2020-08-28 tvanderlippe@chromium.org Typecheck persistence/FileSystemWorkspaceBinding.js with TypeScript
2020-08-28 szuend@chromium.org Fix blur handler of BreakPointEditDialog
2020-08-28 tvanderlippe@chromium.org Typecheck persistence/EditFileSystemView.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:1066415,chromium:1081452
Tbr: devtools-waterfall-sheriff-onduty@grotations.appspotmail.com
Change-Id: I390512c15e7c9f396f64e28631e0c5234ca6842f
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2381449Reviewed-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@{#802708}

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': 'd4a7e12496b5d698a41eada7baf9647b2413962c',
+  'devtools_frontend_revision': '6ec121d8c3d5d0a91e78ea4731b02f40af4ad43d',
   # 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.