Roll src/third_party/dart eb4ab61349..d3a5b82355 (4 commits)

dart-lang/sdk@d3a5b82355 Spell checking: allow "`" as a delimiter in code.
dart-lang/sdk@5e323ba031 [CFE] Allow eof in assert to avoid crash
dart-lang/sdk@63b9a155f7 [CFE] Fix potential parser crash when parsing typedef
dart-lang/sdk@5fa4ec4564 [pkg:vm_service] misc cleanup in pkg:vm_service

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': 'eb4ab613491b2965deba3157c33ca402b59d3b2d',
+  'dart_revision': 'd3a5b8235557ea72b2e69c5647d512fd2cec3fbd',
 
   # WARNING: DO NOT EDIT MANUALLY
   # The lines between blank lines above and below are generated by a script. See create_updated_flutter_deps.py