Dart: Simplifies the handle watcher. Various cleanups and bugfixes.

mojo/public/dart/src/message_pipe.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 core;
 
 
 class _MojoMessagePipeNatives {
   static List MojoCreateMessagePipe(int flags)
       native "MojoMessagePipe_Create";
@@ skipping 95 matching lines @@
       status = MojoResult.INVALID_ARGUMENT;
       return null;
     }
 
     assert((result is List) && (result.length == 3));
     var readResult = new MojoMessagePipeReadResult.fromList(result);
 
     // Copy out the handles that were read.
     if (handles != null) {
       for (var i = 0; i < readResult.handlesRead; i++) {
-        handles[i].h = mojoHandles[i];
+        handles[i] = new RawMojoHandle(mojoHandles[i]);
       }
     }
 
     status = readResult.status;
     return readResult;
   }
 
   MojoMessagePipeReadResult query() => read(null);
 }
 
@@ skipping 19 matching lines @@
     RawMojoHandle end1 = new RawMojoHandle(result[1]);
     RawMojoHandle end2 = new RawMojoHandle(result[2]);
     MojoMessagePipe pipe = new MojoMessagePipe._();
     pipe.endpoints = new List(2);
     pipe.endpoints[0] = new MojoMessagePipeEndpoint(end1);
     pipe.endpoints[1] = new MojoMessagePipeEndpoint(end2);
     pipe.status = new MojoResult(result[0]);
     return pipe;
   }
 }