Roll src/third_party/dart f144d5fdca56..1e4a56ee7202 (20 commits)

[skia-flutter-autoroll]

https://dart.googlesource.com/sdk.git/+log/f144d5fdca56..1e4a56ee7202

git log f144d5f..1e4a56e --date=short --first-parent --format='%ad %ae %s'
2020-04-04 pquitslund@google.com remove type params for list param args
2020-04-04 rnystrom@google.com Migrate language_2/double to NNBD.
2020-04-04 rnystrom@google.com Migrate language_2/double_literals to NNBD.
2020-04-04 rnystrom@google.com Migrate language_2/constructor to NNBD.
2020-04-04 scheglov@google.com Update analyzer expectation for language/const/switch2_test
2020-04-04 scheglov@google.com Match InterfaceType(s) using allSupertypes.
2020-04-04 rnystrom@google.com Migrate language_2/control_flow_collections to NNBD.
2020-04-03 alexmarkov@google.com [tests/nnbd] Fix lib/async/zone_error_callback_test for NNBD strong mode
2020-04-03 scheglov@google.com Add default values for optional parameters in const/constructor2_test
2020-04-03 alexmarkov@google.com [tests/nnbd] Fix lib/isolate tests for NNBD strong mode
2020-04-03 bkonyi@google.com Revert "[ VM / DartDev ] Fixed issue where trying to find the directory of the Dart executable would fail if we encountered a relative symlink while trying to determine the absolute path."
2020-04-03 aam@google.com Revert "[vm] Share some comparison and condition code across platforms."
2020-04-03 liama@google.com [nnbd/libs] Fix nullability issue in file_impl
2020-04-03 rnystrom@google.com Migrate language_2/deferred to NNBD.
2020-04-03 sortie@google.com [benchmark] Remove dart-ast, dart-aot-ast, and dart-bytecode targets.
2020-04-03 liama@google.com [nnbd/libs] Fix nullability issues in secure sockets
2020-04-03 bkonyi@google.com [ VM / DartDev ] Re-enable DartDev
2020-04-03 askesc@google.com [vm] Distinguish between bool objects by a single bit in their pointers.
2020-04-03 askesc@google.com [vm] Share some comparison and condition code across platforms.
2020-04-03 askesc@google.com Revert "[dart:_http] Allow the embedder to prohibit HTTP traffic."

Created with:
gclient setdep -r src/third_party/dart@1e4a56ee7202

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