handle antialiased rendering as premultiplied

core/fxge/dib/fx_dib_main.cpp

 // 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
 
 #include "core/fxge/fx_dib.h"
 
 #include <limits.h>
 
@@ skipping 49 matching lines @@
 
 bool CFX_DIBSource::SkipToScanline(int line, IFX_Pause* pPause) const {
   return false;
 }
 
 CFX_DIBitmap::CFX_DIBitmap() {
   m_bExtBuf = false;
   m_pBuffer = nullptr;
   m_pPalette = nullptr;
 #ifdef _SKIA_SUPPORT_PATHS_
-  m_bUnPreMultiply = false;
+  m_nFormat = Format::kCleared;
 #endif
 }
 
 #define _MAX_OOM_LIMIT_ 12000000
 bool CFX_DIBitmap::Create(int width,
                           int height,
                           FXDIB_Format format,
                           uint8_t* pBuffer,
                           int pitch) {
   m_pBuffer = nullptr;
@@ skipping 1607 matching lines @@
                                uint32_t* pSrcPalette) {
   m_pBitmap = pdfium::MakeUnique<CFX_DIBitmap>();
   if (!m_pBitmap->Create(width, height, src_format)) {
     m_pBitmap.reset();
     return false;
   }
   if (pSrcPalette)
     m_pBitmap->CopyPalette(pSrcPalette);
   return true;
 }