add local caching for skia draws

core/fxge/skia/fx_skia_device.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.
 
 #ifndef CORE_FXGE_SKIA_FX_SKIA_DEVICE_H_
 #define CORE_FXGE_SKIA_FX_SKIA_DEVICE_H_
 
 #if defined(_SKIA_SUPPORT_)
 
 #include "core/fxge/include/ifx_renderdevicedriver.h"
 
 class SkCanvas;
 class SkMatrix;
 class SkPaint;
 class SkPath;
 class SkPictureRecorder;
+class SkiaState;
 struct SkIRect;
 
 class CFX_SkiaDeviceDriver : public IFX_RenderDeviceDriver {
  public:
   CFX_SkiaDeviceDriver(CFX_DIBitmap* pBitmap,
                        FX_BOOL bRgbByteOrder,
                        CFX_DIBitmap* pOriDevice,
                        FX_BOOL bGroupKnockout);
   explicit CFX_SkiaDeviceDriver(SkPictureRecorder* recorder);
   CFX_SkiaDeviceDriver(int size_x, int size_y);
@@ skipping 88 matching lines @@
                       const CFX_Matrix* pMatrix,
                       const FX_RECT& clip_rect,
                       int alpha,
                       FX_BOOL bAlphaMode) override;
 
   virtual uint8_t* GetBuffer() const;
 
   void PaintStroke(SkPaint* spaint,
                    const CFX_GraphStateData* pGraphState,
                    const SkMatrix& matrix);
+  void Flush();
   SkPictureRecorder* GetRecorder() const { return m_pRecorder; }
   void PreMultiply();
+  SkCanvas* SkiaCanvas() { return m_pCanvas; }
+  void Dump() const;
 
  private:
+  friend class SkiaState;
+
   CFX_DIBitmap* m_pBitmap;
   CFX_DIBitmap* m_pOriDevice;
   SkCanvas* m_pCanvas;
   SkPictureRecorder* const m_pRecorder;
+  std::unique_ptr<SkiaState> m_pCache;
   FX_BOOL m_bRgbByteOrder;
   FX_BOOL m_bGroupKnockout;
 };
 #endif  // defined(_SKIA_SUPPORT_)
 
 #endif  // CORE_FXGE_SKIA_FX_SKIA_DEVICE_H_