Update dart2js diagnostics to prepare for filtering.

tests/compiler/dart2js/mock_compiler.dart

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 library mock_compiler;
 
 import "package:expect/expect.dart";
 import 'dart:async';
 import 'dart:collection';
 
@@ skipping 321 matching lines @@
     var script = new Script(uri, new MockFile(source));
     var library = new LibraryElementX(script);
     library.libraryTag = new LibraryName(null, null, null);
     parseScript(source, library);
     library.setExports(library.localScope.values.toList());
     registerSource(uri, source);
     libraries.putIfAbsent(uri.toString(), () => library);
     return library;
   }
 
-  void reportWarning(Spannable node, var message) {
-    if (message is! Message) message = message.message;
-    warnings.add(new WarningMessage(node, message));
-    reportDiagnostic(spanFromSpannable(node),
-        'Warning: $message', api.Diagnostic.WARNING);
-  }
-
-  void reportError(Spannable node,
-                   MessageKind errorCode,
-                   [Map arguments = const {}]) {
-    Message message = errorCode.message(arguments);
-    errors.add(new WarningMessage(node, message));
-    reportDiagnostic(spanFromSpannable(node), '$message', api.Diagnostic.ERROR);
-  }
-
-  void reportInfo(Spannable node,
-                   MessageKind errorCode,
-                   [Map arguments = const {}]) {
-    Message message = errorCode.message(arguments);
-    infos.add(new WarningMessage(node, message));
-    reportDiagnostic(spanFromSpannable(node), '$message', api.Diagnostic.INFO);
-  }
-
-  void reportHint(Spannable node,
-                   MessageKind errorCode,
-                   [Map arguments = const {}]) {
-    Message message = errorCode.message(arguments);
-    hints.add(new WarningMessage(node, message));
-    reportDiagnostic(spanFromSpannable(node), '$message', api.Diagnostic.HINT);
+  // TODO(johnniwinther): Remove this when we don't filter certain type checker
+  // warnings.
+  void reportWarning(Spannable node, MessageKind errorCode,
+                     [Map arguments = const {}]) {
+    reportDiagnostic(node,
+        errorCode.error(arguments, terseDiagnostics),
+        api.Diagnostic.WARNING);
   }
 
   void reportFatalError(Spannable node,
                         MessageKind errorCode,
                         [Map arguments = const {}]) {
     reportError(node, errorCode, arguments);
   }
 
-  void reportMessage(SourceSpan span, var message, api.Diagnostic kind) {
-    var diagnostic = new WarningMessage(null, message.message);
+  void reportDiagnostic(Spannable node,
+                        Diagnostic message,
+                        api.Diagnostic kind) {
+    var diagnostic = new WarningMessage(node, message.message);
     if (kind == api.Diagnostic.ERROR) {
       errors.add(diagnostic);
     } else if (kind == api.Diagnostic.WARNING) {
       warnings.add(diagnostic);
     } else if (kind == api.Diagnostic.INFO) {
       infos.add(diagnostic);
     } else if (kind == api.Diagnostic.HINT) {
       hints.add(diagnostic);
     }
-    reportDiagnostic(span, "$message", kind);
-  }
-
-  void reportDiagnostic(SourceSpan span, String message, api.Diagnostic kind) {
     if (diagnosticHandler != null) {
+      SourceSpan span = spanFromSpannable(node);
       if (span != null) {
-        diagnosticHandler(span.uri, span.begin, span.end, message, kind);
+        diagnosticHandler(span.uri, span.begin, span.end, '$message', kind);
       } else {
-        diagnosticHandler(null, null, null, message, kind);
+        diagnosticHandler(null, null, null, '$message', kind);
       }
     }
   }
 
   bool get compilationFailed => !errors.isEmpty;
 
   void clearMessages() {
     warnings = [];
     errors = [];
     hints = [];
@@ skipping 179 matching lines @@
     } else {
       sourceFile = compiler.sourceFiles[uri.toString()];
     }
     if (sourceFile != null && begin != null && end != null) {
       print(sourceFile.getLocationMessage(message, begin, end, true, (x) => x));
     } else {
       print(message);
     }
   };
 }