Add SkImage->draw() call with src and dst rects.

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 66 matching lines @@
      * 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*);
 
     /**
+     *  Draw the image, cropped to the src rect, to the dst rect of a canvas. 
+     *  If src is larger than the bounds of the image, the rest of the image is 
+     *  filled with transparent black pixels. 

[reed1, 2013/07/19 19:32:30]

// See SkCanvas::drawBitmapRectToRect for similar behavior.

+     */
+    void draw(SkCanvas*, const SkRect* src, const SkRect& dst, const SkPaint*);
+    
+    /**
      *  Encode the image's pixels and return the result as a new SkData, which
      *  the caller must manage (i.e. call unref() when they are done).
      *
      *  If the image type cannot be encoded, or the requested encoder type is
      *  not supported, this will return NULL.
      */
     SkData* encode(SkImageEncoder::Type t = SkImageEncoder::kPNG_Type,
                    int quality = 80) const;
 
 protected:
@@ skipping 10 matching lines @@
     const int       fWidth;
     const int       fHeight;
     const uint32_t  fUniqueID;
 
     static uint32_t NextUniqueID();
 
     typedef SkRefCnt INHERITED;
 };
 
 #endif