Use SkPaintImageFilter of a bitmap to implement box reflection masks.

third_party/WebKit/Source/platform/graphics/BoxReflection.h

 // Copyright 2016 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 BoxReflection_h
 #define BoxReflection_h
 
 #include "platform/PlatformExport.h"
 #include "third_party/skia/include/core/SkPicture.h"
 #include "wtf/PassRefPtr.h"
 #include "wtf/RefPtr.h"
 
 class SkImageFilter;
 class SkMatrix;
-class SkPicture;
 
 namespace blink {
 
 class FloatRect;
 
 // A reflection, as created by -webkit-box-reflect. Consists of:
 // * a direction (either vertical or horizontal)
 // * an offset to be applied to the reflection after flipping about the
 //   x- or y-axis, according to the direction
 // * a mask image, which will be applied to the reflection before the
@@ skipping 39 matching lines @@
 }
 
 inline bool operator!=(const BoxReflection& a, const BoxReflection& b)
 {
     return !(a == b);
 }
 
 } // namespace blink
 
 #endif // BoxReflection_h