Use FastaMessage instead of String. Part 1.

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

Index: pkg/front_end/lib/src/fasta/source/diet_listener.dart
diff --git a/pkg/front_end/lib/src/fasta/source/diet_listener.dart b/pkg/front_end/lib/src/fasta/source/diet_listener.dart
index 27347e4836348edde5ea5dcf31d294dc965fb015..c8c41ec22ac6941021c7b0b3b1ebfdc5eaa9d27f 100644
--- a/pkg/front_end/lib/src/fasta/source/diet_listener.dart
+++ b/pkg/front_end/lib/src/fasta/source/diet_listener.dart
@@ -19,7 +19,7 @@ import 'package:kernel/class_hierarchy.dart' show ClassHierarchy;
 
 import 'package:kernel/core_types.dart' show CoreTypes;
 
-import '../fasta_codes.dart' show FastaMessage, codeExpectedBlockToSkip;
+import '../fasta_codes.dart' show Message, codeExpectedBlockToSkip;
 
 import '../parser/parser.dart' show MemberKind, Parser, optional;
 
@@ -518,7 +518,7 @@ class DietListener extends StackListener {
   }
 
   @override
-  Token handleUnrecoverableError(Token token, FastaMessage message) {
+  Token handleUnrecoverableError(Token token, Message message) {
     if (enableNative && message.code == codeExpectedBlockToSkip) {
       Token recover = library.loader.target.skipNativeClause(token);
       if (recover != null) return recover;
@@ -611,9 +611,9 @@ class DietListener extends StackListener {
   }
 
   @override
-  void addCompileTimeErrorFromMessage(FastaMessage message) {
-    library.deprecated_addCompileTimeError(message.charOffset, message.message,
-        fileUri: message.uri,
+  void addCompileTimeError(Message message, int charOffset) {
+    library.deprecated_addCompileTimeError(charOffset, message.message,
+        fileUri: uri,
         // We assume this error has already been reported by OutlineBuilder.
         silent: true);
   }