Add a simple inksplash example

sky/sdk/lib/framework/animation/generators.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 '../scheduler.dart' as scheduler;
 import 'curves.dart';
 import 'dart:async';
 import 'dart:math' as math;
-import 'dart:sky' as sky;
 import 'mechanics.dart';
 
 abstract class Generator {
   Stream<double> get onTick;
   void cancel();
 }
 
 class FrameGenerator extends Generator {
   Function onDone;
   StreamController _controller;
 
   Stream<double> get onTick => _controller.stream;
 
   int _animationId = 0;
   bool _cancelled = false;
 
   FrameGenerator({this.onDone}) {
     _controller = new StreamController(
       sync: true,
       onListen: _scheduleTick,
       onCancel: cancel);
   }
 
   void cancel() {
     if (_cancelled) {
       return;
     }
     if (_animationId != 0) {
-      sky.window.cancelAnimationFrame(_animationId);
+      scheduler.cancelAnimationFrame(_animationId);
     }
     _animationId = 0;
     _cancelled = true;
     if (onDone != null) {
       onDone();
     }
   }
 
   void _scheduleTick() {
     assert(_animationId == 0);
-    _animationId = sky.window.requestAnimationFrame(_tick);
+    _animationId = scheduler.requestAnimationFrame(_tick);
   }
 
   void _tick(double timeStamp) {
     _animationId = 0;
     _controller.add(timeStamp);
     if (!_cancelled) {
       _scheduleTick();
     }
   }
 }
@@ skipping 93 matching lines @@
   double _update(double timeStamp) {
     double previousTime = _previousTime;
     _previousTime = timeStamp;
     if (previousTime == 0.0)
       return timeStamp;
     double deltaT = timeStamp - previousTime;
     system.update(deltaT);
     return timeStamp;
   }
 }