[vm] Don't enable the profiler by default. Enable the profiler at startup with --observe, or later …

runtime/observatory/lib/src/service/object.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.
 
 part of service;
 
 // Some value smaller than the object ring, so requesting a large array
 // doesn't result in an expired ref because the elements lapped it in the
 // object ring.
 const int kDefaultFieldLimit = 100;
@@ skipping 877 matching lines @@
   }
 
   Future setName(String newName) {
     return invokeRpc('setVMName', {'name': newName});
   }
 
   Future<ServiceObject> getFlagList() {
     return invokeRpc('getFlagList', {});
   }
 
+  Future enableProfiler() {
+    return invokeRpc("_enableProfiler", {});
+  }
+
   Future<ServiceObject> _streamListen(String streamId) {
     Map params = {
       'streamId': streamId,
     };
     // Ignore network errors on stream listen.
     return invokeRpc('streamListen', params)
         .catchError((e) => ignoreNetworkErrors(e));
   }
 
   Future<ServiceObject> _streamCancel(String streamId) {
@@ skipping 3791 matching lines @@
   final String alias;
   final String method;
   final String service;
 
   Service(this.alias, this.method, this.service) {
     assert(this.alias != null);
     assert(this.method != null);
     assert(this.service != null);
   }
 }