Roll src/third_party/dart b3457c8cc2c1..32ce9c7872e2 (7 commits) (#15504)

https://dart.googlesource.com/sdk.git/+log/b3457c8cc2c1..32ce9c7872e2

git log b3457c8cc2c1..32ce9c7872e2 --date=short --first-parent --format='%ad %ae %s'
2020-01-11 brianwilkerson@google.com Enable prefer_collection_literals in three packages
2020-01-11 brianwilkerson@google.com Hook up the fix for use_function_type_syntax_for_parameters
2020-01-11 brianwilkerson@google.com Add a fix for prefer_iterable_whereType
2020-01-11 scheglov@google.com Stop passing ContextBuilder to Workspace(s).
2020-01-11 scheglov@google.com Use ElementTypeProvider in MethodInvocationResolver.
2020-01-11 scheglov@google.com Extract BinaryExpressionResolver.
2020-01-11 scheglov@google.com Issue 40062. Restore check for extededType subtype.

Created with:
  gclient setdep -r src/third_party/dart@32ce9c7872e2

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': 'b3457c8cc2c1d8451d61fa8c6ab4a3d7529f7d76',
+  'dart_revision': '32ce9c7872e241b338502c56e78109fa079ff6c5',
 
   # WARNING: DO NOT EDIT MANUALLY
   # The lines between blank lines above and below are generated by a script. See create_updated_flutter_deps.py