use special-image for imagefilters and save/restore layer

include/core/SkDevice.h

 /*
  * Copyright 2010 The Android Open Source Project
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #ifndef SkDevice_DEFINED
 #define SkDevice_DEFINED
 
 #include "SkRefCnt.h"
 #include "SkCanvas.h"
 #include "SkColor.h"
 #include "SkSurfaceProps.h"
 
 class SkBitmap;
 class SkClipStack;
 class SkDraw;
 class SkDrawFilter;
 class SkImageFilterCache;
 struct SkIRect;
 class SkMatrix;
 class SkMetaData;
 class SkRegion;
+class SkSpecialImage;
 class GrRenderTarget;
 
 class SK_API SkBaseDevice : public SkRefCnt {
 public:
     /**
      *  Construct a new device.
     */
     explicit SkBaseDevice(const SkSurfaceProps&);
     virtual ~SkBaseDevice();
 
@@ skipping 234 matching lines @@
         onCreateDevice on this device with kNeverTile_TileExpectation.
      */
     virtual void drawDevice(const SkDraw&, SkBaseDevice*, int x, int y,
                             const SkPaint&) = 0;
 
     virtual void drawTextOnPath(const SkDraw&, const void* text, size_t len, const SkPath&,
                                 const SkMatrix*, const SkPaint&);
     virtual void drawTextRSXform(const SkDraw&, const void* text, size_t len, const SkRSXform[],
                                  const SkPaint&);
 
+    virtual void drawSpecial(const SkDraw&, SkSpecialImage*, int x, int y, const SkPaint&);
+    virtual sk_sp<SkSpecialImage> makeSpecial(const SkBitmap&);
+    virtual sk_sp<SkSpecialImage> makeSpecial(const SkImage*);
+    virtual sk_sp<SkSpecialImage> asSpecial();
+
     bool readPixels(const SkImageInfo&, void* dst, size_t rowBytes, int x, int y);
 
     ///////////////////////////////////////////////////////////////////////////
 
     /** Update as needed the pixel value in the bitmap, so that the caller can
         access the pixels directly.
         @return The device contents as a bitmap
     */
     virtual const SkBitmap& onAccessBitmap() = 0;
 
@@ skipping 103 matching lines @@
     SkSurfaceProps fSurfaceProps;
 
 #ifdef SK_DEBUG
     bool        fAttachedToCanvas;
 #endif
 
     typedef SkRefCnt INHERITED;
 };
 
 #endif