Replace a forgotten call to SkImage::draw() by SkCanvas::drawImageRect()

src/image/SkImage.cpp

Index: src/image/SkImage.cpp
diff --git a/src/image/SkImage.cpp b/src/image/SkImage.cpp
index 13b6fcd463a8db574b53ffb24af8ef3183fab77e..41ac2165cbaa5756b48259c52ff7498b59163bfc 100644
--- a/src/image/SkImage.cpp
+++ b/src/image/SkImage.cpp
@@ -135,6 +135,6 @@ bool SkImage_Base::onReadPixels(SkBitmap* bitmap, const SkIRect& subset) const {
     paint.setXfermodeMode(SkXfermode::kClear_Mode);
     canvas.drawRect(dstR, paint);
 
-    const_cast<SkImage_Base*>(this)->onDrawRectToRect(&canvas, &srcR, dstR, NULL);
+    canvas.drawImageRect(this, &srcR, dstR);
     return true;
 }