Clip inkwell splash around the floating action button

sky/engine/core/painting/Canvas.idl

Index: sky/engine/core/painting/Canvas.idl
diff --git a/sky/engine/core/painting/Canvas.idl b/sky/engine/core/painting/Canvas.idl
index 95cacfc3b2c2bd8f98518f941ab5269f3c27a64e..538e492905fec0d317325082afcfbefe3e73898f 100644
--- a/sky/engine/core/painting/Canvas.idl
+++ b/sky/engine/core/painting/Canvas.idl
@@ -10,7 +10,8 @@ interface Canvas {
   readonly attribute float width;
 
   void save();
-  void saveLayer(Rect bounds /* optional */, Paint paint /* optional */);
+  // TODO(jackson): Paint should be optional, but making it optional causes crash
+  void saveLayer(Rect bounds, /* optional */ Paint paint);
   void restore();
 
   void translate(float dx, float dy);
@@ -20,6 +21,8 @@ interface Canvas {
   void concat(Float32List matrix4);
 
   void clipRect(Rect rect);
+  void clipRRect(RRect rrect);
+  void clipPath(Path path);
 
   void drawLine(float x0, float y0, float x1, float y1, Paint paint);
   void drawPicture(Picture picture);