cleanup fasta token classes

pkg/analyzer/lib/src/summary/fasta/stack_listener.dart

Index: pkg/analyzer/lib/src/summary/fasta/stack_listener.dart
diff --git a/pkg/analyzer/lib/src/summary/fasta/stack_listener.dart b/pkg/analyzer/lib/src/summary/fasta/stack_listener.dart
index 1b04d9b1b3df7812dfe06e9a35b0a1f4eaa39220..d8b29ea7d4148d9a4b933890f3eabd8fb577fde1 100644
--- a/pkg/analyzer/lib/src/summary/fasta/stack_listener.dart
+++ b/pkg/analyzer/lib/src/summary/fasta/stack_listener.dart
@@ -9,7 +9,9 @@ import 'dart:collection' show Queue;
 import 'package:front_end/src/fasta/parser.dart'
     show IdentifierContext, Listener, MemberKind;
 
-import 'package:front_end/src/fasta/scanner.dart' show BeginGroupToken, Token;
+import 'package:front_end/src/fasta/scanner.dart' show Token;
+
+import 'package:front_end/src/scanner/token.dart' show BeginToken;
 
 enum NullValue {
   Arguments,
@@ -96,7 +98,7 @@ abstract class StackListener extends Listener {
     push(NullValue.TypeVariables);
   }
 
-  void handleParenthesizedExpression(BeginGroupToken token) {
+  void handleParenthesizedExpression(BeginToken token) {
     debugEvent("ParenthesizedExpression");
   }