Fix two type errors and dart2dart status.

dart/sdk/lib/_internal/compiler/implementation/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 'dart:async';
 import 'dart:mirrors';
 
 import 'dart:_foreign_helper' show JS, JS_CURRENT_ISOLATE;
@@ skipping 384 matching lines @@
       JsVariableMirror mirror = new JsVariableMirror.from(field, metadata);
       if (mirror != null) {
         result[mirror.simpleName] = mirror;
         mirror._owner = this;
       }
     }
     return result;
   }
 
   Map<Symbol, Mirror> get members {
-    Map<Symbol, Mirror> result = variables;
+    Map<Symbol, Mirror> result = new Map<Symbol, Mirror>.from(variables);
     for (JsMethodMirror method in _methods) {
       if (method.isSetter) {
         String name = n(method.simpleName);
         name = name.substring(0, name.length - 1);
         // Filter-out setters corresponding to variables.
         if (result[s(name)] is VariableMirror) continue;
       }
       // Use putIfAbsent to filter-out getters corresponding to variables.
       result.putIfAbsent(method.simpleName, () => method);
     }
@@ skipping 283 matching lines @@
 List extractKeys(victim) {
   return JS('List', '''
 (function(victim, hasOwnProperty) {
   var result = [];
   for (var key in victim) {
     if (hasOwnProperty.call(victim, key)) result.push(key);
   }
   return result;
 })(#, Object.prototype.hasOwnProperty)''', victim);
 }