Trivial code style changes in animation code.

sky/sdk/lib/widgets/material.dart

Index: sky/sdk/lib/widgets/material.dart
diff --git a/sky/sdk/lib/widgets/material.dart b/sky/sdk/lib/widgets/material.dart
index cc7ebffb9afd690cd593a79cbb691f3b53a90616..107193b4ebea716719a6b1ee07adf09d34bc2df8 100644
--- a/sky/sdk/lib/widgets/material.dart
+++ b/sky/sdk/lib/widgets/material.dart
@@ -39,18 +39,22 @@ class Material extends AnimatedComponent {
   int level;
   Color color;
 
-  AnimationBuilder _builder;
+  final AnimationBuilder _builder = new AnimationBuilder();

[Matt Perry, 2015/07/13 17:32:55]

Wouldn't this cause us to allocate a new object for Materials that we're going
to throw away?

[abarth-chromium, 2015/07/13 17:41:06]

Constructors for final fields are called lazily the first time someone reads
them.

[abarth-chromium, 2015/07/13 17:44:59]

s/Constructors/initializers/

 
   void initState() {
-    _builder = new AnimationBuilder()
+    _builder
       ..shadow = new AnimatedType<double>(level.toDouble())
       ..backgroundColor = _getBackgroundColor(type, color)
       ..borderRadius = edges[type]
       ..shape = type == MaterialType.circle ? Shape.circle : Shape.rectangle;
     watchPerformance(_builder.createPerformance(
-        [_builder.shadow], duration: _kAnimateShadowDuration));
+        [_builder.shadow],
+        duration: _kAnimateShadowDuration
+    ));
     watchPerformance(_builder.createPerformance(
-        [_builder.backgroundColor], duration: _kAnimateColorDuration));
+        [_builder.backgroundColor],
+        duration: _kAnimateColorDuration
+    ));
     super.initState();
   }