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

include/core/SkImage.h

Index: include/core/SkImage.h
diff --git a/include/core/SkImage.h b/include/core/SkImage.h
index c2ee5093fb679898c7c94d37814db7a1dc9d3049..85875d566f3786e9da6e6e523279d3bda28894a2 100644
--- a/include/core/SkImage.h
+++ b/include/core/SkImage.h
@@ -84,6 +84,15 @@ public:
     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. 
+     *
+     *  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).
      *