[Effen] Port fn.dart from the legacy sky.Node backend to the RenderNode backend, which is currently…

sky/framework/components/ink_well.dart

Index: sky/framework/components/ink_well.dart
diff --git a/sky/framework/components/ink_well.dart b/sky/framework/components/ink_well.dart
index 096fa007963b8465bbb0fdaf8b554921e9436857..cc7181be3b1dc643d548d756fb3ec35293861719 100644
--- a/sky/framework/components/ink_well.dart
+++ b/sky/framework/components/ink_well.dart
@@ -45,14 +45,13 @@ class InkWell extends Component implements ScrollClient {
     );
   }
 
-  sky.ClientRect _getBoundingRect() => (getRoot() as sky.Element).getBoundingClientRect();
-
   void _startSplash(sky.GestureEvent event) {
     setState(() {
       if (_splashes == null)
         _splashes = new LinkedHashSet<SplashController>();
       var splash;
-      splash = new SplashController(_getBoundingRect(), event.x, event.y,
+      var root = getRoot();
+      splash = new SplashController(root.rect, event.x, event.y,
                                     pointer: event.primaryPointer,
                                     onDone: () { _splashDone(splash); });
       _splashes.add(splash);