Add fine grained command line and service protocol control over timeline streams recording

runtime/observatory/lib/src/elements/timeline_page.dart

 // Copyright (c) 2015, 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 timeline_page_element;
 
 import 'dart:async';
 import 'dart:convert';
 import 'dart:html';
 import 'observatory_element.dart';
@@ skipping 39 matching lines @@
   Future refresh() async {
     return postMessage('refresh');
   }
 
   Future clear() async {
     await app.vm.invokeRpc('_clearVMTimeline', {});
     return postMessage('clear');
   }
 
   Future recordOn() async {
-    return app.vm.invokeRpc('_setVMTimelineFlag', {
-      '_record': 'all',
+    return app.vm.invokeRpc('_setVMTimelineFlags', {
+      'recordedStreams': ['all'],
     });
   }
 
   Future recordOff() async {
-    return app.vm.invokeRpc('_setVMTimelineFlag', {
-      '_record': 'none',
+    return app.vm.invokeRpc('_setVMTimelineFlags', {
+      'recordedStreams': [],
     });
   }
 
   _updateSize() {
     IFrameElement e = $['root'];
     final totalHeight = window.innerHeight;
     final top = e.offset.top;
     final bottomMargin = 32;
     final mainHeight = totalHeight - top - bottomMargin;
     e.style.setProperty('height', '${mainHeight}px');
     e.style.setProperty('width', '100%');
   }
 
 
   StreamSubscription _resizeSubscription;
 }