Clip inkwell splash around the floating action button

sky/sdk/lib/framework/rendering/box.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 'dart:math' as math;
 import 'dart:sky' as sky;
 import 'dart:typed_data';
 import 'object.dart';
 import '../painting/shadows.dart';
 import 'package:vector_math/vector_math.dart';
@@ skipping 421 matching lines @@
   void performLayout() {
     if (child != null) {
       child.layout(_getInnerConstraints(constraints));
       size = child.size;
     } else {
       performResize();
     }
   }
 }
 
-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) {
       canvas.save();
       canvas.clipRect(new Rect.fromSize(size));
       child.paint(canvas);
       canvas.restore();
     }
   }
 }
 
+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 }) {
     assert(padding != null);
     this.padding = padding;
     this.child = child;
   }
 
   EdgeDims _padding;
   EdgeDims get padding => _padding;
@@ skipping 654 matching lines @@
 
   void defaultPaint(RenderObjectDisplayList canvas) {
     RenderBox child = firstChild;
     while (child != null) {
       assert(child.parentData is ParentDataType);
       canvas.paintChild(child, child.parentData.position);
       child = child.parentData.nextSibling;
     }
   }
 }