Adding public API method on SkImage for extracting the GPU texture handle.

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 54 matching lines @@
 
     static SkImage* NewRasterCopy(const Info&, const void* pixels, size_t rowBytes);
     static SkImage* NewRasterData(const Info&, SkData* pixels, size_t rowBytes);
     static SkImage* NewEncodedData(SkData*);
     static SkImage* NewTexture(GrTexture*);
 
     int width() const { return fWidth; }
     int height() const { return fHeight; }
     uint32_t uniqueID() const { return fUniqueID; }
 
+    /**
+     * Return the GrTexture that stores the image pixels. Calling getTexture
+     * does not affect the reference count of the GrTexture object.
+     * Will return NULL if the image does not use a texture.
+     */
+    GrTexture* getTexture();
+
     SkShader*   newShaderClamp() const;
     SkShader*   newShader(SkShader::TileMode, SkShader::TileMode) const;
 
     void draw(SkCanvas*, SkScalar x, SkScalar y, const SkPaint*);
 
 protected:
     SkImage(int width, int height) :
         fWidth(width),
         fHeight(height),
         fUniqueID(NextUniqueID()) {
 
         SkASSERT(width >= 0);
         SkASSERT(height >= 0);
     }
 
 private:
     const int       fWidth;
     const int       fHeight;
     const uint32_t  fUniqueID;
 
     static uint32_t NextUniqueID();
 
     typedef SkRefCnt INHERITED;
 };
 
 #endif