Roll src/third_party/dart c561a9eacc1b..fe9f30c3896e (7 commits) (#14475

)

https://dart.googlesource.com/sdk.git/+log/c561a9eacc1b..fe9f30c3896e

git log c561a9eacc1b..fe9f30c3896e --date=short --first-parent --format='%ad %ae %s'
2019-12-13 gityuan@gmail.com [timeline] support vm events available to systrace
2019-12-13 srujzs@google.com Skip all html tests for d8
2019-12-13 rnystrom@google.com Turn the Dart 2.0 migration tool into an NNBD migration tool.
2019-12-12 scheglov@google.com Stop setting AST properties for DDC.
2019-12-12 zichangguo@google.com [dart:io] RawSocketOption.fromInt should follow the same endian as host
2019-12-12 zichangguo@google.com [vm/debugger] --trace-debugger-stacktrace prints async causal stack trace
2019-12-12 rnystrom@google.com Move NNBD tests (language_2/nnbd) to new NNBD test directory.

Created with:
  gclient setdep -r src/third_party/dart@fe9f30c3896e

If this roll has caused a breakage, revert this CL and stop the roller
using the controls here:
https://autoroll.skia.org/r/dart-sdk-flutter-engine
Please CC dart-vm-team@google.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/+/master/autoroll/README.md

Bug: None
Tbr: dart-vm-team@google.com

DEPS

@@ -34,7 +34,7 @@ vars = {
   # Dart is: https://github.com/dart-lang/sdk/blob/master/DEPS.
   # You can use //tools/dart/create_updated_flutter_deps.py to produce
   # updated revision list of existing dependencies.
-  'dart_revision': 'c561a9eacc1b3d0a93980ef5119f77bf88511a15',
+  'dart_revision': 'fe9f30c3896e7146195ea52434c5082b309b6ee0',
 
   # WARNING: DO NOT EDIT MANUALLY
   # The lines between blank lines above and below are generated by a script. See create_updated_flutter_deps.py

ci/licenses_golden/licenses_third_party

@@ -1,4 +1,4 @@
-Signature: b48f64e897d07a9966a0eafc40b79835
+Signature: 4a9c6b6941eaabf6dfbd9b350ca992a3
 
 UNUSED LICENSES: