Clip inkwell splash around the floating action button

sky/engine/core/painting/CanvasPath.h

 // 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.
 
 #ifndef SKY_ENGINE_CORE_PAINTING_PATH_H_
 #define SKY_ENGINE_CORE_PAINTING_PATH_H_
 
 #include "math.h"
 
 #include "sky/engine/core/painting/Rect.h"
@@ skipping 25 matching lines @@
     void lineTo(float x, float y)
     {
         m_path.lineTo(x, y);
     }
 
     void arcTo(const Rect& rect, float startAngle, float sweepAngle, bool forceMoveTo)
     {
         m_path.arcTo(rect.sk_rect, startAngle*180.0/M_PI, sweepAngle*180.0/M_PI, forceMoveTo);
     }
 
+    void addOval(const Rect& oval)
+    {
+        m_path.addOval(oval.sk_rect);
+    }
+
     void close()
     {
         m_path.close();
     }
 
     const SkPath& path() const { return m_path; }
 
 private:
     CanvasPath();
 
     SkPath m_path;
 };
 
 } // namespace blink
 
 #endif  // SKY_ENGINE_CORE_PAINTING_PATH_H_