Transforms are very common in SVG, but nsDisplayTransform and the layer that is created for it involve a lot of overhead. The cost can be way more than a simple matrix multiply (i.e. multiple allocations, lots of extra code path followed, etc.). For static SVG this is all just extra cost for no gain. We should think about whether we can avoid creating nsDisplayTransform items unless we know that the transform will create an active layer. We can perhaps propagate transforms down through BuildDisplayList, or something.