handle antialiased rendering as premultiplied

core/fxge/fx_dib.h

 // Copyright 2014 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_FX_DIB_H_
 #define CORE_FXGE_FX_DIB_H_
 
 #include <memory>
@@ skipping 353 matching lines @@
   bool CompositeRect(int dest_left,
                      int dest_top,
                      int width,
                      int height,
                      uint32_t color,
                      int alpha_flag = 0,
                      void* pIccTransform = nullptr);
 
   bool ConvertColorScale(uint32_t forecolor, uint32_t backcolor);
 
-#ifdef _SKIA_SUPPORT_PATHS_
+#if defined _SKIA_SUPPORT_PATHS_
   bool IsMarkedForUnPreMultiply() const { return m_bUnPreMultiply; }
-
+  bool IsOffscreen() const { return m_bIsOffscreen; }
   void MarkForUnPreMultiply(bool mark) { m_bUnPreMultiply = mark; }
+  void SetIsOffscreen(bool isOff) { m_bIsOffscreen = isOff; }
+  void UnPreMultiply();
 #endif
 
  protected:
   bool GetGrayData(void* pIccTransform = nullptr);
 
   uint8_t* m_pBuffer;
   bool m_bExtBuf;
-#ifdef _SKIA_SUPPORT_PATHS_
+#if defined _SKIA_SUPPORT_PATHS_
+  bool m_bIsOffscreen;
   bool m_bUnPreMultiply;
 #endif
 };
 
 class CFX_DIBExtractor {
  public:
   explicit CFX_DIBExtractor(const CFX_DIBSource* pSrc);
   ~CFX_DIBExtractor();
 
   CFX_DIBitmap* GetBitmap() { return m_pBitmap.get(); }
@@ skipping 284 matching lines @@
   int m_Status;
   FX_RECT m_ClipBox;
   uint32_t m_Flags;
   int m_AlphaFlag;
   void* m_pIccTransform;
   bool m_bRgbByteOrder;
   int m_BlendType;
 };
 
 #endif  // CORE_FXGE_FX_DIB_H_