Update SkSpecialImage API

src/core/SkSpecialImage.h

 /*
  * Copyright 2016 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file
  */
 
 #ifndef SkSpecialImage_DEFINED
 #define SkSpecialImage_DEFINED
 
+#include "SkNextID.h"
 #include "SkRefCnt.h"
 
+// remove this when internal_getProxy goes away (see skbug.com/4965)
+#include "SkImageFilter.h"
+
 class GrTexture;
 class SkBitmap;
 class SkCanvas;
 class SkImage;
 struct SkImageInfo;
 class SkPaint;
 class SkSpecialSurface;
 
+enum {
+    kNeedNewImageUniqueID_SpecialImage = 0
+};
+
 /**
  * This is a restricted form of SkImage solely intended for internal use. It
  * differs from SkImage in that:
  *      - it can only be backed by raster or gpu (no generators)
  *      - it can be backed by a GrTexture larger than its nominal bounds
  *      - it can't be drawn tiled
  *      - it can't be drawn with MIPMAPs
  * It is similar to SkImage in that it abstracts how the pixels are stored/represented.
  *
  * Note: the contents of the backing storage outside of the subset rect are undefined.
  */
 class SkSpecialImage : public SkRefCnt {
 public:
     int width() const { return fSubset.width(); }
     int height() const { return fSubset.height(); }
+    uint32_t uniqueID() const { return fUniqueID; }
+    virtual bool isOpaque() const { return false; }
+    virtual size_t getSize() const = 0;
 
     /**
      *  Draw this SpecialImage into the canvas.
      */
     void draw(SkCanvas*, SkScalar x, SkScalar y, const SkPaint*) const;
 
     static SkSpecialImage* NewFromImage(const SkIRect& subset, const SkImage*);
-    static SkSpecialImage* NewFromRaster(const SkIRect& subset, const SkBitmap&);
-    static SkSpecialImage* NewFromGpu(const SkIRect& subset, GrTexture*);
+    static SkSpecialImage* NewFromRaster(SkImageFilter::Proxy*,
+                                         const SkIRect& subset,
+                                         const SkBitmap&);
+    static SkSpecialImage* NewFromGpu(SkImageFilter::Proxy*,
+                                      const SkIRect& subset,
+                                      uint32_t uniqueID,
+                                      GrTexture*, 
+                                      SkAlphaType at = kPremul_SkAlphaType);
 
     /**
      *  Create a new surface with a backend that is compatible with this image.
      */
     SkSpecialSurface* newSurface(const SkImageInfo&) const;
 
+    // These three internal methods will go away (see skbug.com/4965)
+    bool internal_getBM(SkBitmap* result);
+    static SkSpecialImage* internal_fromBM(SkImageFilter::Proxy*, const SkBitmap&);
+    SkImageFilter::Proxy* internal_getProxy();
+
 protected:
-    SkSpecialImage(const SkIRect& subset) : fSubset(subset) { }
+    SkSpecialImage(SkImageFilter::Proxy* proxy, const SkIRect& subset, uint32_t uniqueID)
+        : fSubset(subset)
+        , fUniqueID(kNeedNewImageUniqueID_SpecialImage == uniqueID ? SkNextID::ImageID()
+                                                                   : uniqueID)
+        , fProxy(proxy) {
+    }
 
-    // The following 3 are for testing and shouldn't be used.
+    // The following 3 are for testing and shouldn't be used. (see skbug.com/4965)
     friend class TestingSpecialImageAccess;
     friend class TestingSpecialSurfaceAccess;
     const SkIRect& subset() const { return fSubset; }
 
     /**
      *  If the SpecialImage is backed by cpu pixels, return the const address
      *  of those pixels and, if not null, return the ImageInfo and rowBytes.
      *  The returned address is only valid while the image object is in scope.
      *
      *  The returned ImageInfo represents the backing memory. Use 'subset'
      *  to get the active portion's dimensions.
      *
      *  On failure, return false and ignore the pixmap parameter.
      */
     bool peekPixels(SkPixmap*) const;
 
     /**
      *  If the SpecialImage is backed by a gpu texture, return that texture.
      *  The active portion of the texture can be retrieved via 'subset'.
      */
     GrTexture* peekTexture() const;
 
+    // TODO: remove this ASAP (see skbug.com/4965)
+    SkImageFilter::Proxy* proxy() const { return fProxy; }
+
 private:
-    const SkIRect fSubset;
+    const SkIRect   fSubset;
+    const uint32_t  fUniqueID;
+
+    // TODO: remove this ASAP (see skbug.com/4965)
+    SkImageFilter::Proxy* fProxy;
 
     typedef SkRefCnt INHERITED;
 };
 
 #endif