Address comments
Address comments

https://dart-review.googlesource.com/c/sdk/+/22760/1/pkg/front_end/lib/src/fasta/parser/parser.dart#4991
Change-Id: I63b0e0940376d04fdcaeecd11df3d04bf800a2d3
Reviewed-on: https://dart-review.googlesource.com/22881
Reviewed-by: Brian Wilkerson <1f7641b6b14c52b9163524ab8d9aabff80176f21@google.com>
Commit-Queue: Dan Rubel <5c5a7a1a3f9344592135bed55605519045cfa711@google.com>

dart-lang/sdk,dart-lang/sdk,dartino/dart-sdk,dart-archive/dart-sdk,dartino/dart-sdk,dartino/dart-sdk,dart-archive/dart-sdk,dartino/dart-sdk,dartino/dart-sdk,dart-archive/dart-sdk,dart-lang/sdk,dart-lang/sdk,dartino/dart-sdk,dartino/dart-sdk,dart-archive/dart-sdk,dart-archive/dart-sdk,dart-archive/dart-sdk,dart-archive/dart-sdk,dart-archive/dart-sdk,dartino/dart-sdk,dart-lang/sdk,dart-archive/dart-sdk,dartino/dart-sdk,dart-lang/sdk,dart-lang/sdk,dart-lang/sdk