Add prescale option to deferred params

include/core/SkImage.h

 /*
  * Copyright 2012 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #ifndef SkImage_DEFINED
 #define SkImage_DEFINED
 
@@ skipping 325 matching lines @@
      *  If the result image cannot be created, or the result would be transparent black, null
      *  is returned, in which case the offset and outSubset parameters should be ignored by the
      *  caller.
      */
     sk_sp<SkImage> makeWithFilter(const SkImageFilter* filter, const SkIRect& subset,
                                   const SkIRect& clipBounds, SkIRect* outSubset,
                                   SkIPoint* offset) const;
 
     /** Drawing params for which a deferred texture image data should be optimized. */
     struct DeferredTextureImageUsageParams {
+        DeferredTextureImageUsageParams() : fPreScaleMipLevel(0) {}
+        DeferredTextureImageUsageParams(const SkMatrix matrix, const SkFilterQuality quality, 
+                                        int preScaleMipLevel)
+            : fMatrix(matrix), fQuality(quality), fPreScaleMipLevel(preScaleMipLevel) {}
         SkMatrix        fMatrix;
         SkFilterQuality fQuality;
+        int             fPreScaleMipLevel;
     };
 
     /**
      * This method allows clients to capture the data necessary to turn a SkImage into a texture-
      * backed image. If the original image is codec-backed this will decode into a format optimized
      * for the context represented by the proxy. This method is thread safe with respect to the
      * GrContext whence the proxy came. Clients allocate and manage the storage of the deferred
      * texture data and control its lifetime. No cleanup is required, thus it is safe to simply free
      * the memory out from under the data.
      *
@@ skipping 86 matching lines @@
 
 private:
     const int       fWidth;
     const int       fHeight;
     const uint32_t  fUniqueID;
 
     typedef SkRefCnt INHERITED;
 };
 
 #endif