Add operator==, hashCode, and toString for Rect and Point dart classes.

sky/engine/core/painting/Rect.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.
 
 part of dart.sky;
 
 class Rect {
   Float32List _value;
   double get left => _value[0];
   double get top => _value[1];
   double get right => _value[2];
   double get bottom => _value[3];
 
   void setLTRB(double left, double top, double right, double bottom) {

[sethladd, 2015/05/27 22:19:49]

Dart has named constructors. You could do:

Rect.LTRB(double left, double top, double right, double bottom) {
  _value = new Float32List.fromList([left, top, right, bottom]);
}

[Matt Perry, 2015/05/28 17:05:54]

Done.

     _value = new Float32List.fromList([left, top, right, bottom]);
   }
+
+  bool operator ==(other) {
+    if (!(other is Rect)) return false;
+    for (var i = 0; i < 4; ++i) {
+      if (_value[i] != other._value[i])
+        return false;
+    }
+    return true;
+  }
+  int get hashCode {
+    return _value.fold(373, (value, item) => (37 * value + item.hashCode));
+  }
+  String toString() {

[sethladd, 2015/05/27 22:19:49]

consider using => here

[Matt Perry, 2015/05/28 17:05:54]

Done.

+    return "Rect.LTRB($left, $top, $right, $bottom)";
+  }
 }