Clip inkwell splash around the floating action button

sky/sdk/lib/framework/rendering/box.dart

Index: sky/sdk/lib/framework/rendering/box.dart
diff --git a/sky/sdk/lib/framework/rendering/box.dart b/sky/sdk/lib/framework/rendering/box.dart
index 53021807e804c5eb4ebaef53ee673336ccfeb4f7..6b5d0f0d419cbbfa67b664f69779734f7f36c86f 100644
--- a/sky/sdk/lib/framework/rendering/box.dart
+++ b/sky/sdk/lib/framework/rendering/box.dart
@@ -439,8 +439,8 @@ class RenderShrinkWrapWidth extends RenderProxyBox {
   }
 }
 
-class RenderClip extends RenderProxyBox {
-  RenderClip({ RenderBox child }) : super(child);
+class RenderClipRect extends RenderProxyBox {
+  RenderClipRect({ RenderBox child }) : super(child);
 
   void paint(RenderObjectDisplayList canvas) {
     if (child != null) {
@@ -452,6 +452,22 @@ class RenderClip extends RenderProxyBox {
   }
 }
 
+class RenderClipOval extends RenderProxyBox {
+  RenderClipOval({ RenderBox child }) : super(child);
+
+  void paint(RenderObjectDisplayList canvas) {
+    if (child != null) {
+      Rect rect = new Rect.fromSize(size);
+      canvas.saveLayer(rect, new Paint());
+      Path path = new Path();
+      path.addOval(rect);
+      canvas.clipPath(path);
+      child.paint(canvas);
+      canvas.restore();
+    }
+  }
+}
+
 class RenderPadding extends RenderBox with RenderObjectWithChildMixin<RenderBox> {
 
   RenderPadding({ EdgeDims padding, RenderBox child }) {