handle antialiased rendering as premultiplied

core/fxge/ge/cfx_renderdevice.cpp

 // 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
 
 #include "core/fxge/cfx_renderdevice.h"
 
 #include <algorithm>
 #include <memory>
@@ skipping 804 matching lines @@
                                        const CFX_DIBSource* pMask,
                                        int left,
                                        int top,
                                        int bitmap_alpha,
                                        int blend_type) {
   return m_pDeviceDriver->SetBitsWithMask(pBitmap, pMask, left, top,
                                           bitmap_alpha, blend_type);
 }
 #endif
 
-#ifdef _SKIA_SUPPORT_PATHS_
-void CFX_RenderDevice::UnPreMultiplyDevice() {
-  SkASSERT(0);
-}
-#endif
-
 bool CFX_RenderDevice::DrawNormalText(int nChars,
                                       const FXTEXT_CHARPOS* pCharPos,
                                       CFX_Font* pFont,
                                       FX_FLOAT font_size,
                                       const CFX_Matrix* pText2Device,
                                       uint32_t fill_color,
                                       uint32_t text_flags) {
   int nativetext_flags = text_flags;
   if (m_DeviceClass != FXDC_DISPLAY) {
     if (!(text_flags & FXTEXT_PRINTGRAPHICTEXT)) {
@@ skipping 237 matching lines @@
                              fill_color, stroke_color, fill_mode,
                              FXDIB_BLEND_NORMAL)) {
         return false;
       }
     }
     if (pClippingPath)
       pClippingPath->Append(&TransformedPath, pUser2Device);
   }
   return true;
 }