Bug 697647 - VideoFrame's visible region should use the pre-transform size rather than the raw video buffer size. r=roc

layout/generic/nsVideoFrame.cpp

@@ -288,7 +288,7 @@ nsVideoFrame::BuildLayer(nsDisplayListBuilder* aBuilder,
   transform.Translate(r.TopLeft());
   transform.Scale(r.Width()/frameSize.width, r.Height()/frameSize.height);
   layer->SetTransform(gfx3DMatrix::From2D(transform));
-  layer->SetVisibleRegion(nsIntRect(0, 0, videoSize.width, videoSize.height));
+  layer->SetVisibleRegion(nsIntRect(0, 0, frameSize.width, frameSize.height));
   nsRefPtr<Layer> result = layer.forget();
   return result.forget();
 }