cleanup fasta token classes

pkg/front_end/lib/src/fasta/source/diet_parser.dart

Index: pkg/front_end/lib/src/fasta/source/diet_parser.dart
diff --git a/pkg/front_end/lib/src/fasta/source/diet_parser.dart b/pkg/front_end/lib/src/fasta/source/diet_parser.dart
index 60a6189ffff72c49a09d7a375bcfb7f607cfac33..7d8a8e526df68797b7c207236802d3738f6d9e0c 100644
--- a/pkg/front_end/lib/src/fasta/source/diet_parser.dart
+++ b/pkg/front_end/lib/src/fasta/source/diet_parser.dart
@@ -12,9 +12,7 @@ import '../parser/listener.dart' show Listener;
 
 import '../parser/parser.dart' show MemberKind, optional;
 
-import '../scanner/token.dart' show BeginGroupToken;
-
-import '../../scanner/token.dart' show Token;
+import '../../scanner/token.dart' show BeginToken, Token;
 
 // TODO(ahe): Move this to parser package.
 class DietParser extends ClassMemberParser {
@@ -33,7 +31,7 @@ class DietParser extends ClassMemberParser {
       }
       return reportUnexpectedToken(token).next;
     }
-    BeginGroupToken beginGroupToken = token;
+    BeginToken beginGroupToken = token;
     Token endToken = beginGroupToken.endGroup;
     listener.endFormalParameters(0, token, endToken, kind);
     return endToken.next;