Turn off the code that is forcing stocksapp to build 50 times a second, and change the code that tr…

sky/sdk/lib/widgets/widget.dart

 // Copyright 2015 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.
 
 import 'dart:async';
 import 'dart:collection';
 import 'dart:mirrors';
 import 'dart:sky' as sky;
 
 import '../base/hit_test.dart';
@@ skipping 494 matching lines @@
   }
 
   Widget build();
 
 }
 
 Set<Component> _dirtyComponents = new Set<Component>();
 bool _buildScheduled = false;
 bool _inRenderDirtyComponents = false;
 
+List<int> _debugFrameTimes = <int>[];
+
 void _buildDirtyComponents() {
   Stopwatch sw;
   if (_shouldLogRenderDuration)
     sw = new Stopwatch()..start();
 
   try {
     sky.tracing.begin('Widgets._buildDirtyComponents');
     _inRenderDirtyComponents = true;
 
     List<Component> sortedDirtyComponents = _dirtyComponents.toList();
     sortedDirtyComponents.sort((Component a, Component b) => a._order - b._order);
     for (var comp in sortedDirtyComponents) {
       comp._buildIfDirty();
     }
 
     _dirtyComponents.clear();
     _buildScheduled = false;
   } finally {
     _inRenderDirtyComponents = false;
     sky.tracing.end('Widgets._buildDirtyComponents');
   }
 
   Widget._notifyMountStatusChanged();
 
   if (_shouldLogRenderDuration) {
     sw.stop();
-    print('Render took ${sw.elapsedMicroseconds} microseconds');
+    _debugFrameTimes.add(sw.elapsedMicroseconds);
+    if (_debugFrameTimes.length >= 1000) {
+      _debugFrameTimes.sort();
+      const int i = 99;
+      print('_buildDirtyComponents: ${i+1}th fastest frame out of the last ${_debugFrameTimes.length}: ${_debugFrameTimes[i]} microseconds');
+      _debugFrameTimes.clear();
+    }

[abarth-chromium, 2015/06/29 22:39:57]

Did you mean to check this in?

   }
 }
 
 void _scheduleComponentForRender(Component c) {
   assert(!_inRenderDirtyComponents);
   _dirtyComponents.add(c);
 
   if (!_buildScheduled) {
     _buildScheduled = true;
     new Future.microtask(_buildDirtyComponents);
@@ skipping 453 matching lines @@
     if (root.parent == null) {
       // we haven't attached it yet
       assert(_container.child == null);
       _container.child = root;
     }
     assert(root.parent == _container);
   }
 
   Widget build() => builder();
 }