Use FastaMessage instead of String. Part 1.

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

Index: pkg/front_end/lib/src/fasta/source/outline_builder.dart
diff --git a/pkg/front_end/lib/src/fasta/source/outline_builder.dart b/pkg/front_end/lib/src/fasta/source/outline_builder.dart
index 65f79ed30ee154abebce8b459600a4cff5a828fa..044ca093a9108cb6eed45f2c44277f65beee7acb 100644
--- a/pkg/front_end/lib/src/fasta/source/outline_builder.dart
+++ b/pkg/front_end/lib/src/fasta/source/outline_builder.dart
@@ -6,7 +6,7 @@ library fasta.outline_builder;
 
 import 'package:kernel/ast.dart' show ProcedureKind;
 
-import '../fasta_codes.dart' show FastaMessage, codeExpectedBlockToSkip;
+import '../fasta_codes.dart' show Message, codeExpectedBlockToSkip;
 
 import '../parser/parser.dart' show FormalParameterType, MemberKind, optional;
 
@@ -156,7 +156,7 @@ class OutlineBuilder extends UnhandledListener {
   }
 
   @override
-  void handleRecoverExpression(Token token, FastaMessage message) {
+  void handleRecoverExpression(Token token, Message message) {
     debugEvent("RecoverExpression");
     push(NullValue.Expression);
     push(token.charOffset);
@@ -839,7 +839,7 @@ class OutlineBuilder extends UnhandledListener {
   }
 
   @override
-  void handleRecoverableError(Token token, FastaMessage message) {
+  void handleRecoverableError(Token token, Message message) {
     if (silenceParserErrors) {
       debugEvent("RecoverableError");
     } else {
@@ -848,7 +848,7 @@ class OutlineBuilder extends UnhandledListener {
   }
 
   @override
-  Token handleUnrecoverableError(Token token, FastaMessage message) {
+  Token handleUnrecoverableError(Token token, Message message) {
     if (enableNative && message.code == codeExpectedBlockToSkip) {
       var target = library.loader.target;
       Token recover = target.skipNativeClause(token);
@@ -861,9 +861,9 @@ class OutlineBuilder extends UnhandledListener {
   }
 
   @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);
   }
 
   @override