IsCanvasFrame(nsIFrame *aFrame)
IsCanvasFrame(nsIPresContext* aPresContext, nsIFrame *aFrame)
IsCanvasFrame(nsIFrame *aFrame){  nsCOMPtr<nsIAtom> frameType;  aFrame->GetFrameType(getter_AddRefs(frameType));  return (frameType == nsLayoutAtoms::canvasFrame ||          frameType == nsLayoutAtoms::rootFrame ||          frameType == nsLayoutAtoms::pageFrame);}