Revert "Canonicalize raw type"

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

Index: sdk/lib/_internal/compiler/implementation/js_backend/runtime_types.dart
diff --git a/sdk/lib/_internal/compiler/implementation/js_backend/runtime_types.dart b/sdk/lib/_internal/compiler/implementation/js_backend/runtime_types.dart
index a4545e6e26259dd8e7aed34f008848a22bb26a45..2064f0948462af1fcc7431bdc93b563a37ed24da 100644
--- a/sdk/lib/_internal/compiler/implementation/js_backend/runtime_types.dart
+++ b/sdk/lib/_internal/compiler/implementation/js_backend/runtime_types.dart
@@ -23,10 +23,11 @@ class RuntimeTypeInformation {
         InterfaceType interface = t;
         ClassElement element = t.element;
         if (element.typeVariables.isEmpty) return;
-        bool isRaw = interface.isRaw;
+        bool isRaw = interface.typeArguments.isEmpty;
         if (isRaw && !expandRawType) return;
         builder.add('<');
-        Iterable items = interface.typeArguments;
+        Iterable items =
+            isRaw ? element.typeVariables : interface.typeArguments;
         var stringify = isRaw ? (_) => 'dynamic' : (type) => type.toString();
         bool first = true;
         for (var item in items) {
@@ -48,7 +49,7 @@ class RuntimeTypeInformation {
   static bool hasTypeArguments(DartType type) {
     if (type is InterfaceType) {
       InterfaceType interfaceType = type;
-      return !interfaceType.isRaw;
+      return !interfaceType.typeArguments.isEmpty;
     }
     return false;
   }