nsresult rv = nsGenericHTMLLeafElement::GetAttribute(kNameSpaceID_None, nsHTMLAtoms::width, aValue);
NS_ENSURE_ARG_POINTER(aWidth); *aWidth = 0;
nsHTMLImageElement::GetWidth(nsAWritableString& aValue){  nsresult rv = nsGenericHTMLLeafElement::GetAttribute(kNameSpaceID_None,                                                       nsHTMLAtoms::width,                                                       aValue);  if (rv == NS_CONTENT_ATTR_NOT_THERE) {    PRInt32 width = 0;    aValue.Truncate();     // A zero width most likely means that the image is not loaded yet.    if (NS_SUCCEEDED(GetWidth(&width)) && width) {      nsAutoString widthStr;      widthStr.AppendInt(width);      aValue.Append(widthStr);      aValue.Append(NS_LITERAL_STRING("px"));    }  }  return NS_OK;}