Non fatal errors on duplicated accessors

dart/pkg/compiler/lib/src/warnings.dart

Index: dart/pkg/compiler/lib/src/warnings.dart
diff --git a/dart/pkg/compiler/lib/src/warnings.dart b/dart/pkg/compiler/lib/src/warnings.dart
index 082a41eb6ef04613e426c5d69d3370d8faf8f744..908d9cfef9d5b111fc132a44ab4a774317a18aa8 100644
--- a/dart/pkg/compiler/lib/src/warnings.dart
+++ b/dart/pkg/compiler/lib/src/warnings.dart
@@ -182,7 +182,19 @@ main() => new B();
       "Cannot resolve type '#{typeName}'.");
 
   static const MessageKind DUPLICATE_DEFINITION = const MessageKind(
-      "Duplicate definition of '#{name}'.");
+      "Duplicate definition of '#{name}'.",
+      howToFix: "Try to rename or remove this definition.",
+      examples: const ["""
+class C {
+  void f() {}
+  int get f => 1;
+}
+
+main() {
+  new C();
+}
+
+"""]);
 
   static const MessageKind EXISTING_DEFINITION = const MessageKind(
       "Existing definition of '#{name}'.");