Modify JS annotations in runtime typedef handling to not drag in native types.

sdk/lib/_internal/compiler/js_lib/js_mirrors.dart

 // Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 library dart._js_mirrors;
 
 import 'shared/runtime_data.dart' as encoding;
 import 'shared/embedded_names.dart' show
     ALL_CLASSES,
     LAZIES,
@@ skipping 2747 matching lines @@
       }
       return typeArgument._mangledName;
     }
     representation =
         runtimeTypeToString(type, onTypeVariable: substituteTypeVariable);
   }
   if (representation != null) {
     return reflectClassByMangledName(
         getMangledTypeName(createRuntimeType(representation)));
   }
-  if (type != null && JS('Object|Null', '#.typedef', type) != null) {
+  if (type != null && JS('', '#.typedef', type) != null) {
     return typeMirrorFromRuntimeTypeRepresentation(
-        owner, JS('Object', '#.typedef', type));
-  } else if (type != null && JS('Object|Null', '#.func', type) != null) {
+        owner, JS('', '#.typedef', type));
+  } else if (type != null && JS('', '#.func', type) != null) {
     return new JsFunctionTypeMirror(type, owner);
   }
   return reflectClass(Function);
 }
 
 Symbol computeQualifiedName(DeclarationMirror owner, Symbol simpleName) {
   if (owner == null) return simpleName;
   String ownerName = n(owner.qualifiedName);
   return s('$ownerName.${n(simpleName)}');
 }
@@ skipping 155 matching lines @@
   // have a part (following a '.') that starts with '_'.
   const int UNDERSCORE = 0x5f;
   if (name.isEmpty) return true;
   int index = -1;
   do {
     if (name.codeUnitAt(index + 1) == UNDERSCORE) return false;
     index = name.indexOf('.', index + 1);
   } while (index >= 0 && index + 1 < name.length);
   return true;
 }