This issue was originally filed by @aam

There is visible degradation in performance of Dartium b/w 0.8.7 and 0.8.5 releases of Dart Editor.

To measure it I modified sunflower.dart so it draws 100 sunflowers size of 1900 to 2000 dots and exits.
0.8.5 version of Dartium exists in 2 seconds, 0.8.7 - in 17 seconds.

PS C:\g\dart-repo\dart> (measure-command {cmd /c C:\dart.28990\chromium\chrome.exe file:///C:/dart/sunflower/web/sunflower.html}).totalseconds
2.0040431

PS C:\g\dart-repo\dart> (measure-command {cmd /c C:\dart.29341\chromium\chrome.exe file:///C:/dart/sunflower/web/sunflower.html}).totalseconds
17.1227792

C:>diff sunflower-original\web\sunflower.html sunflower\web\sunflower.html

--- sunflower-original\web\sunflower.html Thu Oct 31 00:26:38 2013
+++ sunflower\web\sunflower.html Thu Oct 31 00:32:19 2013
@@ -16,9 +16,9 @­@
     <p>A canvas 2D demo.</p>

     <div id="container">

•  <canvas id="canvas" width="300" height="300" class="center"></canvas>
  

•  <canvas id="canvas" width="800" height="800" class="center"></canvas>
  

         <form class="center">

•    <input id="slider" type="range" max="1000" value="500"/>
  

•    <input id="slider" type="range" max="2000" value="500"/>
  

         </form>
         <br/>
         <img src="math.png" width="350px" height="42px" class="center">

C:>diff sunflower-original\web\sunflower.dart sunflower\web\sunflower.dart

--- sunflower-original\web\sunflower.dart Thu Oct 31 00:26:38 2013
+++ sunflower\web\sunflower.dart Thu Oct 31 00:25:30 2013
@@ -11,7 +11,7 @­@
 const int SEED_RADIUS = 2;
 const int SCALE_FACTOR = 4;
 const num TAU = PI * 2;
-const int MAX_D = 300;
+const int MAX_D = 600;
 const num centerX = MAX_D / 2;
 const num centerY = centerX;

@@ -23,8 +23,14 @­@
   (querySelector("#canvas") as CanvasElement).context2D;

 void main() {

• slider.onChange.listen((e) => draw());
• draw();
• for (var i=1900; i < 2000; i++) {
• slider.setAttribute("value", "$i");
• draw();
• }
• window.close();
   }

 /// Draw the complete figure for the current number of seeds.