Dart: Removes name conflicts from generated bindings.

mojo/public/dart/src/proxy.dart

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 part of bindings;
 
 abstract class Proxy extends core.MojoEventStreamListener {
   Map<int, Completer> _completerMap;
   int _nextId = 0;
 
@@ skipping 62 matching lines @@
     }
 
     var completer = new Completer();
     _completerMap[id] = completer;
     return completer.future;
   }
 
   // Need a getter for this for access in subclasses.
   Map<int, Completer> get completerMap => _completerMap;
 }
+
+
+// Generated Proxy classes implement this interface.
+abstract class ProxyBase {
+  final Proxy impl;
+  final String name;
+}