Clip inkwell splash around the floating action button

sky/sdk/lib/framework/components2/floating_action_button.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 '../fn2.dart';
 import '../rendering/box.dart';
 import '../painting/shadows.dart';
 import '../theme2/colors.dart';
 import 'dart:sky' as sky;
 import 'ink_well.dart';
@@ skipping 22 matching lines @@
         callback: (sky.Canvas canvas) {
           const double radius = _kSize / 2.0;
           sky.Paint paint = new sky.Paint()..color = Red[500];
           var builder = new ShadowDrawLooperBuilder()
             ..addShadow(const sky.Size(0.0, 5.0),
                         const sky.Color(0x77000000),
                         5.0);
           paint.setDrawLooper(builder.build());
           canvas.drawCircle(radius, radius, radius, paint);
         },
-        child: new Container(
-          width: _kSize,
-          height: _kSize,
-          child: new InkWell(children: children))),
+        child: new ClipOval(
+          child: new Container(
+            width: _kSize,
+            height: _kSize,
+            child: new InkWell(children: children)
+          )
+        )
+      ),
       level: level);
   }
 
 }