Clean up a bunch of our Dart code.

sky/engine/core/painting/Point.dart

Index: sky/engine/core/painting/Point.dart
diff --git a/sky/engine/core/painting/Point.dart b/sky/engine/core/painting/Point.dart
index 169edd6959605d0f550df1ec9894da4a8f2a1418..bb2cbd95c6984efbe1d98a2045bbb29ae786176a 100644
--- a/sky/engine/core/painting/Point.dart
+++ b/sky/engine/core/painting/Point.dart
@@ -6,17 +6,17 @@ part of dart.sky;
 
 /// Holds 2 floating-point coordinates.
 class Point {
+  const Point(this.x, this.y);
+
   final double x;
   final double y;
 
-  const Point(this.x, this.y);
+  static const Point origin = const Point(0.0, 0.0);
 
   bool operator ==(other) => other is Point && x == other.x && y == other.y;
   Size operator -(Point other) => new Size(x - other.x, y - other.y);
   Point operator +(Size size) => new Point(x + size.width, y + size.height);
 
-  static const Point origin = const Point(0.0, 0.0);
-
   // does the equivalent of "return this - Point(0,0)"
   Size toSize() => new Size(x, y);