Non fatal errors on duplicated accessors

dart/pkg/compiler/lib/src/resolution/class_members.dart

Index: dart/pkg/compiler/lib/src/resolution/class_members.dart
diff --git a/dart/pkg/compiler/lib/src/resolution/class_members.dart b/dart/pkg/compiler/lib/src/resolution/class_members.dart
index 5e753f8c812b4219625d94d5199b184da27c701c..7fd7edc321700678abd130ec76a726c0452d82f9 100644
--- a/dart/pkg/compiler/lib/src/resolution/class_members.dart
+++ b/dart/pkg/compiler/lib/src/resolution/class_members.dart
@@ -348,8 +348,15 @@ abstract class MembersCreator {
       }
     } else {
       assert(declared.name == superMember.name);
+
       if (declared.isStatic) {
         for (Member inherited in superMember.declarations) {
+          if (cls == inherited.declarer.element) {
+            // An error should already have been reported.
+            assert(invariant(declared.element, compiler.compilationFailed));
+            continue;
+          }
+
           reportMessage(
               inherited.element, MessageKind.NO_STATIC_OVERRIDE, () {
             reportErrorWithContext(
@@ -361,6 +368,11 @@ abstract class MembersCreator {
 
       DartType declaredType = declared.functionType;
       for (Member inherited in superMember.declarations) {
+        if (cls == inherited.declarer.element) {
+          // An error should already have been reported.
+          assert(invariant(declared.element, compiler.compilationFailed));
+          continue;
+        }
 
         void reportError(MessageKind errorKind, MessageKind infoKind) {
           reportMessage(