Add alpha type to texture producer

src/gpu/GrTextureParamsAdjuster.h

 /*
  * Copyright 2015 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #ifndef GrTextureMaker_DEFINED
 #define GrTextureMaker_DEFINED
 
@@ skipping 55 matching lines @@
                                     bool coordsLimitedToConstraintRect,
                                     const GrTextureParams::FilterMode* filterOrNullForBicubic,
                                     SkColorSpace* dstColorSpace,
                                     SkSourceGammaTreatment) = 0;
 
     virtual ~GrTextureProducer() {}
 
     int width() const { return fWidth; }
     int height() const { return fHeight; }
     bool isAlphaOnly() const { return fIsAlphaOnly; }
+    virtual SkAlphaType alphaType() const = 0;
     virtual SkColorSpace* getColorSpace() = 0;
 
 protected:
     GrTextureProducer(int width, int height, bool isAlphaOnly)
         : fWidth(width)
         , fHeight(height)
         , fIsAlphaOnly(isAlphaOnly) {}
 
     /** Helper for creating a key for a copy from an original key. */
     static void MakeCopyKeyFromOrigKey(const GrUniqueKey& origKey,
@@ skipping 51 matching lines @@
                                 const SkMatrix& textureMatrix,
                                 const SkRect& constraintRect,
                                 FilterConstraint,
                                 bool coordsLimitedToConstraintRect,
                                 const GrTextureParams::FilterMode* filterOrNullForBicubic,
                                 SkColorSpace* dstColorSpace,
                                 SkSourceGammaTreatment) override;
 
     // We do not ref the texture nor the colorspace, so the caller must keep them in scope while
     // this Adjuster is alive.
-    GrTextureAdjuster(GrTexture*, const SkIRect& area, uint32_t uniqueID, SkColorSpace*);
+    GrTextureAdjuster(GrTexture*, SkAlphaType, const SkIRect& area, uint32_t uniqueID,
+                      SkColorSpace*);
 
 protected:
+    SkAlphaType alphaType() const override { return fAlphaType; }
     SkColorSpace* getColorSpace() override;
     void makeCopyKey(const CopyParams& params, GrUniqueKey* copyKey) override;
     void didCacheCopy(const GrUniqueKey& copyKey) override;
 
     GrTexture* originalTexture() const { return fOriginal; }
 
     /** Returns the content area or null for the whole original texture */
     const SkIRect* contentAreaOrNull() { return fContentArea.getMaybeNull(); }
 
 private:
     SkTLazy<SkIRect>    fContentArea;
     GrTexture*          fOriginal;
+    SkAlphaType         fAlphaType;
     SkColorSpace*       fColorSpace;
     uint32_t            fUniqueID;
 
     GrTexture* refCopy(const CopyParams &copyParams);
 
     typedef GrTextureProducer INHERITED;
 };
 
 /**
  * Base class for sources that start out as something other than a texture (encoded image,
@@ skipping 41 matching lines @@
 
     GrContext* context() const { return fContext; }
 
 private:
     GrContext*  fContext;
 
     typedef GrTextureProducer INHERITED;
 };
 
 #endif