Improve stocks2 performance

sky/sdk/lib/rendering/box.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:math' as math;
 import 'dart:sky' as sky;
 
 import 'package:vector_math/vector_math.dart';
 
 import '../base/debug.dart';
@@ skipping 24 matching lines @@
                         this.left: 0.0 });
   const EdgeDims.symmetric({ double vertical: 0.0,
                              double horizontal: 0.0 })
     : top = vertical, left = horizontal, bottom = vertical, right = horizontal;
 
   final double top;
   final double right;
   final double bottom;
   final double left;
 
-  operator ==(EdgeDims other) => (top == other.top) ||
-                                 (right == other.right) ||
-                                 (bottom == other.bottom) ||
-                                 (left == other.left);
+  bool operator ==(other) {
+    if (identical(this, other))
+      return true;
+    return other is EdgeDims
+        && top == other.top
+        && right == other.right
+        && bottom == other.bottom
+        && left == other.left;
+  }
 
   int get hashCode {
     int value = 373;
     value = 37 * value + top.hashCode;
     value = 37 * value + left.hashCode;
     value = 37 * value + bottom.hashCode;
     value = 37 * value + right.hashCode;
     return value;
   }
   String toString() => "EdgeDims($top, $right, $bottom, $left)";
@@ skipping 114 matching lines @@
 
   Size constrain(Size size) {
     Size result = new Size(constrainWidth(size.width), constrainHeight(size.height));
     if (size is _DebugSize)
       result = new _DebugSize(result, size._owner, size._canBeUsedByParent);
     return result;
   }
 
   bool get isInfinite => maxWidth >= double.INFINITY && maxHeight >= double.INFINITY;
 
+  bool get hasTightWidth => minWidth == maxWidth;
+  bool get hasTightHeight => minHeight == maxHeight;
+  bool get isTight => hasTightWidth && hasTightHeight;
+
+  bool operator ==(other) {
+    if (identical(this, other))
+      return true;
+    return other is BoxConstraints &&
+           minWidth == other.minWidth &&
+           maxWidth == other.maxWidth &&
+           minHeight == other.minHeight &&
+           maxHeight == other.maxHeight;
+  }
   int get hashCode {
     int value = 373;
     value = 37 * value + minWidth.hashCode;
     value = 37 * value + maxWidth.hashCode;
     value = 37 * value + minHeight.hashCode;
     value = 37 * value + maxHeight.hashCode;
     return value;
   }
+
   String toString() => "BoxConstraints($minWidth<=w<$maxWidth, $minHeight<=h<$maxHeight)";
 }
 
 class BoxHitTestEntry extends HitTestEntry {
   const BoxHitTestEntry(HitTestTarget target, this.localPosition) : super(target);
   final Point localPosition;
 }
 
 class BoxParentData extends ParentData {
   Point _position = Point.origin;
@@ skipping 844 matching lines @@
     result.add(new HitTestEntry(this));
     return true;
   }
 
   void paint(RenderObjectDisplayList canvas) {
     if (child != null)
       canvas.paintChild(child, Point.origin);
   }
 
   void paintFrame() {
+    sky.tracing.begin('RenderView.paintFrame');
     RenderObject.debugDoingPaint = true;
-    RenderObjectDisplayList canvas = new RenderObjectDisplayList(sky.view.width, sky.view.height);
-    paint(canvas);
-    sky.view.picture = canvas.endRecording();
-    RenderObject.debugDoingPaint = false;
+    try {
+      RenderObjectDisplayList canvas = new RenderObjectDisplayList(sky.view.width, sky.view.height);
+      paint(canvas);
+      sky.view.picture = canvas.endRecording();
+    } finally {
+      RenderObject.debugDoingPaint = false;
+      sky.tracing.end('RenderView.paintFrame');
+    }
   }
 
 }
 
 // DEFAULT BEHAVIORS FOR RENDERBOX CONTAINERS
 abstract class RenderBoxContainerDefaultsMixin<ChildType extends RenderBox, ParentDataType extends ContainerParentDataMixin<ChildType>> implements ContainerRenderObjectMixin<ChildType, ParentDataType> {
 
   void defaultHitTestChildren(HitTestResult result, { Point position }) {
     // the x, y parameters have the top left of the node's box as the origin
     ChildType child = lastChild;
@@ skipping 11 matching lines @@
 
   void defaultPaint(RenderObjectDisplayList canvas) {
     RenderBox child = firstChild;
     while (child != null) {
       assert(child.parentData is ParentDataType);
       canvas.paintChild(child, child.parentData.position);
       child = child.parentData.nextSibling;
     }
   }
 }