add native draw bitmap with alpha mask

core/fxge/include/cfx_renderdevice.h

 // Copyright 2016 PDFium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // Original code copyright 2014 Foxit Software Inc. http://www.foxitsoftware.com
 
 #ifndef CORE_FXGE_INCLUDE_CFX_RENDERDEVICE_H_
 #define CORE_FXGE_INCLUDE_CFX_RENDERDEVICE_H_
 
 #include <memory>
@@ skipping 235 matching lines @@
                                 const CFX_Matrix* pText2User,
                                 const CFX_Matrix* pUser2Device,
                                 const CFX_GraphStateData* pGraphState,
                                 uint32_t fill_color,
                                 uint32_t stroke_color,
                                 CFX_PathData* pClippingPath,
                                 int nFlag);
 
 #ifdef _SKIA_SUPPORT_
   virtual void DebugVerifyBitmapIsPreMultiplied() const;
+  virtual bool SetBitsWithMask(const CFX_DIBSource* pBitmap,
+                               const CFX_DIBSource* pMask,
+                               int left,
+                               int top,
+                               int bitmap_alpha,
+                               int blend_type);
   void Flush();
 #endif
 
  private:
   void InitDeviceInfo();
   void UpdateClipBox();
   FX_BOOL DrawFillStrokePath(const CFX_PathData* pPathData,
                              const CFX_Matrix* pObject2Device,
                              const CFX_GraphStateData* pGraphState,
                              uint32_t fill_color,
                              uint32_t stroke_color,
                              int fill_mode,
                              int blend_type);
 
   CFX_DIBitmap* m_pBitmap;
   int m_Width;
   int m_Height;
   int m_bpp;
   int m_RenderCaps;
   int m_DeviceClass;
   FX_RECT m_ClipBox;
   std::unique_ptr<IFX_RenderDeviceDriver> m_pDeviceDriver;
 };
 
 #endif  // CORE_FXGE_INCLUDE_CFX_RENDERDEVICE_H_