Update third_party/devtools-frontend a2ca5d5c44..df0ca90392

https://chromium.googlesource.com/devtools/devtools-frontend/+log/a2ca5d5c44..df0ca90392

TBR=aerotwist@chromium.org

Change-Id: I3db2bf865e867523e5c883a9eb9129e70dd5f45b
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1888671Reviewed-by: Yang Guo <yangguo@chromium.org>
Reviewed-by: Paul Lewis <aerotwist@chromium.org>
Commit-Queue: Yang Guo <yangguo@chromium.org>
Cr-Commit-Position: refs/heads/master@{#710732}

DEPS

@@ -243,7 +243,7 @@ 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': 'a2ca5d5c442a1ff23ff228af8c0143887f6722a6',
+  'devtools_frontend_revision': 'df0ca90392989452ad997537308e52a9257f3377',
   # 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.