if(aFrame == nsnull) return NS_ERROR_NULL_POINTER;
NS_GetObjectFramePluginInstance(nsIFrame* aFrame, nsIPluginInstance*& aPluginInstance){	// TODO: any way to determine this cast is safe?	nsObjectFrame* objectFrame = NS_STATIC_CAST(nsObjectFrame*, aFrame);	return objectFrame->GetPluginInstance(aPluginInstance);}