XP_BZERO(&message_data, sizeof(IL_MessageData));
nsCRT::zero(&message_data, sizeof(IL_MessageData));
il_icon_notify(IL_ImageReq *image_req, int icon_number,               XP_ObservableMsg message){    IL_GroupContext *img_cx = image_req->img_cx;    int icon_width, icon_height;    IL_MessageData message_data;    XP_BZERO(&message_data, sizeof(IL_MessageData));      /* Obtain the dimensions of the icon. */    img_cx->img_cb->GetIconDimensions(img_cx->dpy_cx, &icon_width,                                      &icon_height, icon_number);    /* Fill in the message data and notify observers. */    message_data.image_instance = image_req;    message_data.icon_number = icon_number;    message_data.icon_width = icon_width;    message_data.icon_height = icon_height;    XP_NotifyObservers(image_req->obs_list, message, &message_data);}