Support type argument substitution on unnamed mixin applications.

sdk/lib/_internal/compiler/implementation/js_emitter/class_emitter.dart

Index: sdk/lib/_internal/compiler/implementation/js_emitter/class_emitter.dart
diff --git a/sdk/lib/_internal/compiler/implementation/js_emitter/class_emitter.dart b/sdk/lib/_internal/compiler/implementation/js_emitter/class_emitter.dart
index 9d9a89b3d2d6f10006559f594d83367db75f683e..28b6e8e7f3377742725d1edb3ee2a60ea724f0e9 100644
--- a/sdk/lib/_internal/compiler/implementation/js_emitter/class_emitter.dart
+++ b/sdk/lib/_internal/compiler/implementation/js_emitter/class_emitter.dart
@@ -336,8 +336,14 @@ class ClassEmitter extends CodeEmitterHelper {
 
     String reflectionName = task.getReflectionName(classElement, className);
     if (reflectionName != null) {
+      reflectionName = '+$reflectionName';
+    } else if (classElement.isUnnamedMixinApplication &&
+               backend.isNeededForReflection(classElement)) {
+      reflectionName = '-$className';
+    }
+    if (reflectionName != null) {
       if (!backend.isNeededForReflection(classElement)) {
-        enclosingBuilder.addProperty("+$reflectionName", js.number(0));
+        enclosingBuilder.addProperty("$reflectionName", js.number(0));
       } else {
         List<int> types = new List<int>();
         if (classElement.supertype != null) {
@@ -346,7 +352,7 @@ class ClassEmitter extends CodeEmitterHelper {
         for (DartType interface in classElement.interfaces) {
           types.add(task.metadataEmitter.reifyType(interface));
         }
-        enclosingBuilder.addProperty("+$reflectionName",
+        enclosingBuilder.addProperty("$reflectionName",
             new jsAst.ArrayInitializer.from(types.map((typeNumber) =>
                 js.number(typeNumber))));
       }