Update dart:mirrors to use Symbol.

dart/runtime/lib/mirrors_patch.dart

 // Copyright (c) 2012, 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.
 
 import "dart:nativewrappers";
+// TODO(ahe): Move _symbol_dev.Symbol to its own "private" library?
+import "dart:_collection-dev" as _symbol_dev;
 
 /**
  * Returns a [MirrorSystem] for the current isolate.
  */
 patch MirrorSystem currentMirrorSystem() {
   return _Mirrors.currentMirrorSystem();
 }
 
 /**
  * Creates a [MirrorSystem] for the isolate which is listening on
  * the [SendPort].
  */
 patch Future<MirrorSystem> mirrorSystemOf(SendPort port) {
   return _Mirrors.mirrorSystemOf(port);
 }
 
 /**
  * Returns an [InstanceMirror] for some Dart language object.
  *
  * This only works if this mirror system is associated with the
  * current running isolate.
  */
 patch InstanceMirror reflect(Object reflectee) {
   return _Mirrors.reflect(reflectee);
 }
+
+patch class MirrorSystem {
+  /* patch */ static String getName(Symbol symbol) {
+    return _symbol_dev.Symbol.getName(symbol);
+  }
+}