Rename "BorderSide.None" to "BorderSide.none", since it's a constant, and change the sky.Size.infin…

sky/engine/core/painting/Size.dart

Index: sky/engine/core/painting/Size.dart
diff --git a/sky/engine/core/painting/Size.dart b/sky/engine/core/painting/Size.dart
index 0339cf20a696fe8710aa706c2b04225cf3bb18a9..6747a65523e8d4ebf154b6a5ecf6e36f769f417f 100644
--- a/sky/engine/core/painting/Size.dart
+++ b/sky/engine/core/painting/Size.dart
@@ -12,11 +12,11 @@ class Size {
 
   const Size(this.width, this.height);
 
-  const Size.infinite() : width = double.INFINITY, height = double.INFINITY;
-
   const Size.fromWidth(this.width) : height = double.INFINITY;
   const Size.fromHeight(this.height) : width = double.INFINITY;
 
+  static const Size infinite = const Size(double.INFINITY, double.INFINITY);
+
   bool operator ==(other) => other is Size && width == other.width && height == other.height;
 
   // does the equivalent of "return new Point(0,0) + this"