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

src/image/SkImagePriv.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 SkImagePriv_DEFINED
 #define SkImagePriv_DEFINED
 
@@ skipping 21 matching lines @@
  *
  *  If the bitmap's config cannot be converted into a corresponding
  *  SkImage::Info, or the bitmap's pixels cannot be accessed, this will return
  *  NULL.
  */
 extern SkImage* SkNewImageFromBitmap(const SkBitmap&, bool canSharePixelRef);
 
 extern void SkImagePrivDrawPicture(SkCanvas*, SkPicture*,
                                    SkScalar x, SkScalar y, const SkPaint*);
 
+extern void SkImagePrivDrawPicture(SkCanvas*, SkPicture*,
+                                   SkRect src, SkRect dst, const SkPaint*);
 /**
  *  Return an SkImage whose contents are those of the specified picture. Note:
  *  The picture itself is unmodified, and may continue to be used for recording
  */
 extern SkImage* SkNewImageFromPicture(const SkPicture*);
 
 static inline size_t SkImageMinRowBytes(const SkImage::Info& info) {
     size_t rb = info.fWidth * SkImageBytesPerPixel(info.fColorType);
     return SkAlign4(rb);
 }
@@ skipping 10 matching lines @@
 // may be called to see if the surface and the image share the same GrTexture,
 // in which case the surface may need to perform a copy-on-write.
 extern GrTexture* SkTextureImageGetTexture(SkImage* textureImage);
 
 // Update the texture wrapped by an image created with NewTexture. This
 // is called when a surface and image share the same GrTexture and the
 // surface needs to perform a copy-on-write
 extern void SkTextureImageSetTexture(SkImage* image, GrTexture* texture);
 
 #endif