message: Respect .readonly property in printMethod.
diff: @@ -2287,6 +2287,10 @@ function printMethod(path, options, print) {
  parts.push("static ");
  }
  + if (node.readonly) {
  + parts.push("readonly ");
  + }
  +
  if (nodeValue.async) {
  parts.push("async ");
  }
  