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

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

 // Copyright (c) 2013, 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 cpu_profile_table_element;
 
 import 'dart:async';
 import 'dart:html';
 import 'package:observatory/models.dart' as M;
 import 'package:observatory/src/elements/containers/virtual_collection.dart';
@@ skipping 109 matching lines @@
         new NavRefreshElement(queue: _r.queue)..onRefresh.listen(_refresh),
         new NavRefreshElement(label: 'Clear', queue: _r.queue)
           ..onRefresh.listen(_clearCpuProfile),
         new NavNotifyElement(_notifications, queue: _r.queue)
       ]),
     ];
     if (_progress == null) {
       children = content;
       return;
     }
-    content.add(new SampleBufferControlElement(_progress, _progressStream,
+    content.add(new SampleBufferControlElement(_vm, _progress, _progressStream,
         showTag: false, queue: _r.queue));
     if (_progress.status == M.SampleProfileLoadingStatus.loaded) {
       content.add(new BRElement());
       content.addAll(_createTables());
       content.add(new BRElement());
       content.addAll(_createTree());
     }
     children = content;
   }
 
@@ skipping 292 matching lines @@
 
   static double _getExclusiveT(M.ProfileFunction f) =>
       f.normalizedExclusiveTicks;
   static double _getInclusiveT(M.ProfileFunction f) =>
       f.normalizedInclusiveTicks;
   double _getCalleeT(M.ProfileFunction f) =>
       _selected.callees[f] / _selected.callees.values.reduce((a, b) => a + b);
   double _getCallerT(M.ProfileFunction f) =>
       _selected.callers[f] / _selected.callers.values.reduce((a, b) => a + b);
 }