support gradients and stroke+fill

core/fxge/agg/fx_agg_driver.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_AGG_FX_AGG_DRIVER_H_
 #define CORE_FXGE_AGG_FX_AGG_DRIVER_H_
 
 #include "core/include/fxge/fx_ge.h"
@@ skipping 104 matching lines @@
   void CancelDIBits(void* handle) override;
   FX_BOOL DrawDeviceText(int nChars,
                          const FXTEXT_CHARPOS* pCharPos,
                          CFX_Font* pFont,
                          CFX_FontCache* pCache,
                          const CFX_Matrix* pObject2Device,
                          FX_FLOAT font_size,
                          FX_DWORD color,
                          int alpha_flag,
                          void* pIccTransform) override;
-  int GetDriverType() override { return 1; }
+  int GetDriverType() const override { return 1; }
 
   FX_BOOL RenderRasterizer(agg::rasterizer_scanline_aa& rasterizer,
                            FX_DWORD color,
                            FX_BOOL bFullCover,
                            FX_BOOL bGroupKnockout,
                            int alpha_flag,
                            void* pIccTransform);
 
   void SetClipMask(agg::rasterizer_scanline_aa& rasterizer);
 
   virtual uint8_t* GetBuffer() const;
   const CFX_DIBitmap* GetBitmap() const { return m_pBitmap; }
 
  private:
   CFX_DIBitmap* m_pBitmap;
   CFX_ClipRgn* m_pClipRgn;
   CFX_ArrayTemplate<CFX_ClipRgn*> m_StateStack;
   void* m_pPlatformGraphics;
   void* m_pPlatformBitmap;
   void* m_pDwRenderTartget;
   int m_FillFlags;
   int m_DitherBits;
   FX_BOOL m_bRgbByteOrder;
   CFX_DIBitmap* m_pOriDevice;
   FX_BOOL m_bGroupKnockout;
 };
 
 #endif  // CORE_FXGE_AGG_FX_AGG_DRIVER_H_