if (!mRenderer) return NS_OK;
nsSVGOuterSVGFrame::NotifyViewportChange(){  // no point in doing anything when were not init'ed yet:  if (!mViewportInitialized) return NS_OK;  // make sure canvas transform matrix gets (lazily) recalculated:  mCanvasTM = nsnull;    // inform children  SuspendRedraw();  nsIFrame* kid = mFrames.FirstChild();  while (kid) {    nsISVGChildFrame* SVGFrame=nsnull;    kid->QueryInterface(NS_GET_IID(nsISVGChildFrame),(void**)&SVGFrame);    if (SVGFrame)      SVGFrame->NotifyCanvasTMChanged();     kid = kid->GetNextSibling();  }  UnsuspendRedraw();  return NS_OK;}