Fix for Issue 7224

sdk/lib/_internal/compiler/implementation/js_backend/emitter_no_eval.dart

Index: sdk/lib/_internal/compiler/implementation/js_backend/emitter_no_eval.dart
diff --git a/sdk/lib/_internal/compiler/implementation/js_backend/emitter_no_eval.dart b/sdk/lib/_internal/compiler/implementation/js_backend/emitter_no_eval.dart
index 0b6c0f542924bf24f6acfabe93ff5c05d366f62c..9655b9a630e73b054bbdf29446d991a2ca47192a 100644
--- a/sdk/lib/_internal/compiler/implementation/js_backend/emitter_no_eval.dart
+++ b/sdk/lib/_internal/compiler/implementation/js_backend/emitter_no_eval.dart
@@ -123,7 +123,7 @@ $classesCollector.$mangledName = {'': function $mangledName(self, target) {
     }
     String constructorName = namer.safeName(classElement.name.slowToString());
     // Generate the constructor.
-    buffer.add("'': function $constructorName(");
+    buffer.add('"": function $constructorName(');
     buffer.add(Strings.join(argumentNames, ", "));
     buffer.add(") {\n");
     for (int i = 0; i < fields.length; i++) {
@@ -132,6 +132,12 @@ $classesCollector.$mangledName = {'': function $mangledName(self, target) {
     buffer.add(' }');
   }
 
+  void emitSuper(String superName, CodeBuffer buffer) {
+    if (superName != '') {
+      buffer.add(",\n 'super': '$superName'");
+    }
+  }
+
   void emitClassFields(ClassElement classElement,
                        CodeBuffer buffer,
                        bool emitEndingComma,