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

src/image/SkImage_Base.h

Index: src/image/SkImage_Base.h
diff --git a/src/image/SkImage_Base.h b/src/image/SkImage_Base.h
index 9ae13de4aed7c0a3ef20fb9c6f648ec2fd04ceb2..bc54e3a088590dc564c52e4c568c227de43a4dd8 100644
--- a/src/image/SkImage_Base.h
+++ b/src/image/SkImage_Base.h
@@ -15,6 +15,7 @@ public:
     SkImage_Base(int width, int height) : INHERITED(width, height) {}
 
     virtual void onDraw(SkCanvas*, SkScalar x, SkScalar y, const SkPaint*) = 0;
+    virtual void onDraw(SkCanvas*, const SkRect* src, const SkRect& dst, const SkPaint*) = 0;

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

Bad practice to overload a virtual with diff parameters (too easy to have one
shadow the other). Please create a new name, e.g. onDrawRectToRect or something
like that.

     virtual GrTexture* onGetTexture() { return NULL; }
 
     // return a read-only copy of the pixels. We promise to not modify them,