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

src/image/SkImagePriv.cpp

Index: src/image/SkImagePriv.cpp
diff --git a/src/image/SkImagePriv.cpp b/src/image/SkImagePriv.cpp
index c44e439b72c8b29eb82837b6dae19797d4b9569b..1f9778550584400757fb4050769d5cf36c9ab67a 100644
--- a/src/image/SkImagePriv.cpp
+++ b/src/image/SkImagePriv.cpp
@@ -141,3 +141,15 @@ void SkImagePrivDrawPicture(SkCanvas* canvas, SkPicture* picture,
     canvas->drawPicture(*picture);
     canvas->restoreToCount(saveCount);
 }
+
+void SkImagePrivDrawPicture(SkCanvas* canvas, SkPicture* picture,

[Justin Novosad, 2013/07/18 21:54:37]

You need to write a good test for this function.  I<m not sure we need this
override to be implemented. You could leave it empty with something like: 
SkASSERT(0); // Not implemented

+                            SkRect src, SkRect dst, const SkPaint* paint) {
+    int saveCount = canvas->getSaveCount();

[Justin Novosad, 2013/07/18 21:54:37]

No need for this call. This value is returned by saveLayer

+
+    canvas->clipRect(src);

[Justin Novosad, 2013/07/18 21:54:37]

Bug: This clip does not get undone.  Also I think it needs to be applied just
before the call to drawPictures.

+    canvas->saveLayer(&dst, paint);

[reed1, 2013/07/19 14:03:45]

Why saveLayer instead of just save?

+    canvas->translate(dst.x(), dst.y());

[Justin Novosad, 2013/07/18 21:54:37]

This is not the right transform to map src to dst. 

[reed1, 2013/07/19 14:03:45]

SkMatrix has a mapRectToRect helper function you can use, which you could then
concat() onto the canvas.

+
+    canvas->drawPicture(*picture);
+    canvas->restoreToCount(saveCount);
+}