Rename watchPerformance to watch

sky/sdk/lib/widgets/material.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 'package:sky/animation/animation_performance.dart';
 import 'package:sky/painting/box_painter.dart';
 import 'package:sky/widgets/animated_component.dart';
 import 'package:sky/widgets/animation_builder.dart';
 import 'package:sky/widgets/basic.dart';
 import 'package:sky/widgets/default_text_style.dart';
@@ skipping 29 matching lines @@
   Color color;
 
   final AnimationBuilder _builder = new AnimationBuilder();
 
   void initState() {
     _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(
+    watch(_builder.createPerformance(
         [_builder.shadow],
         duration: _kAnimateShadowDuration
     ));
-    watchPerformance(_builder.createPerformance(
+    watch(_builder.createPerformance(
         [_builder.backgroundColor],
         duration: _kAnimateColorDuration
     ));
     super.initState();
   }
 
   void syncFields(Material source) {
     child = source.child;
     type = source.type;
     level = source.level;
@@ skipping 23 matching lines @@
     return color == null ? null : new AnimatedColor(color);
   }
 
   Widget build() {
     return _builder.build(
       new DefaultTextStyle(style: Theme.of(this).text.body1, child: child)
     );
   }
 
 }