Port metrics to RPC

sdk/lib/profiler/profiler.dart

 // Copyright (c) 2014, 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.profiler;
 
 import 'dart:convert';
 
 /// A UserTag can be used to group samples in the Observatory profiler.
 abstract class UserTag {
@@ skipping 168 matching lines @@
 
   static String _printMetric(String id) {
     var metric = _metrics[id];
     if (metric == null) {
       return null;
     }
     return JSON.encode(metric._toJSON());
   }
 
   static String _printMetrics() {
-    var members = [];
+    var metrics = [];
     for (var metric in _metrics.values) {
-      members.add(metric._toJSON());
+      metrics.add(metric._toJSON());
     }
     var map = {
       'type': 'MetricList',
-      'id': 'metrics',
-      'members': members,
+      'metrics': metrics,
     };
     return JSON.encode(map);
   }
 }