Roll src/third_party/dart b52d264..05e70d5 (17 commits) (#15085)

https://dart.googlesource.com/sdk.git/+log/b52d264f5b2f..05e70d5b38cb

git log b52d264..05e70d5 --date=short --first-parent --format='%ad %ae %s'
2019-12-30 whesse@google.com [infra] Add unapproved failures test to builder status script
2019-12-30 zichangguo@google.com [vm/io] add endian.host to RawSocketOption.fromInt
2019-12-30 srawlins@google.com analyzer: move tests for 10 error codes to separate files
2019-12-30 srawlins@google.com analyzer: Fix duplicate error-reporting with duplicate field formals
2019-12-30 srawlins@google.com analyzer: move 'non-error' tests for 12 codes to separate files
2019-12-30 scheglov@google.com Remove reporting duplicate CompileTimeErrorCode.CONST_NOT_INITIALIZED from ConstructorFieldsVerifier.
2019-12-30 devoncarew@google.com [analyzer] improve the cursor insertion position for required params
2019-12-30 scheglov@google.com Simplify SyntheticIdentifier to partial SimpleIdentifier.
2019-12-30 scheglov@google.com Remove 'referencingLibrary' from several Scope.lookupX() methods.
2019-12-29 scheglov@google.com Add canReferenceElementWithoutThisPrefix() to LinterContext.
2019-12-29 devoncarew@google.com [analyzer] fix an issue with the missing_required_param warning ending in two periods
2019-12-29 brianwilkerson@google.com Add a fix for prefer_if_null_operators
2019-12-29 devoncarew@google.com [analyzer] insert missing params before child/children
2019-12-28 paulberry@google.com Migration: teach FixBuilder to add the `required` keyword when necessary.
2019-12-28 mfairhurst@google.com [nnbd_migration] Handle invokeType on function invocation expression
2019-12-28 brianwilkerson@google.com Enable unnecessary_this in several packages
2019-12-28 brianwilkerson@google.com Update the generators to not generate unnecessary uses of "this"

Created with:
  gclient setdep -r src/third_party/dart@05e70d5b38cb

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

Author: skia-flutter-autoroll

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': 'b52d264f5b2f33b224e30acc7856704f50698207',
+  'dart_revision': '05e70d5b38cb1b4e005129a18002fb82ee289524',
 
   # 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: 67f4e29d8adfc6b21bf1b66bf4678677
+Signature: a23e05dee944ceaf341ddc8395792001
 
 UNUSED LICENSES: